Most solar systems are installed on a roof of a house or a building. The exception are solar farms or ground-mounted solar installations but these are rare, and usually 100% commercial solar systems. The reason most solar systems are installed on a roof is because of limited space – especially in the urban environment.

Roofs on the other hand represent significant unused space, and are usually not shaded by trees, nearby buildings, etc – they are the highest point of a building with great sun exposure, which makes them perfect to install solar panels on.

In this article we will discuss solar roofing systems, which integrate roofing materials with solar PV panels or solar thermal systems. Although most roof-mounted solar systems are installed on top of existing roof – be it an asphalt shingles roof or any type of flat roof – these solar systems are not integrated into the roofing material, and therefore are not solar roofs.

What is solar roofing? Roof-integrated solar systems explained.

Solar roofing is a final product which integrates a Solar Panel with the roofing material suitable for either sloped or flat roof. The solar panels used in solar roofing are usually thin-film photovoltaic laminates. Most popular Solar PV laminates commercially used today, are the Unisolar thin-film PV panels.

Unisolar thin-film PV laminates were originally designed to fit into and be integrated with standing seam metal roof panels. Unisolar panels are 15.5 inches wide and fit perfectly into a 16″ standing seam panels, and are attached or laminated with special butyl adhesive that is on the back of each Uni-solar PV panel.

As time progressed and solar integrators were having flat roof leak repair issues with solar systems they installed on flat commercial roofs. After they installed solar mounting racks and attached them to the roof deck, the fasteners would start leaking after a while. Roofing manufacturers answered this issue with different versions of flat roofing materials that integrated Unisolar PV panels – one such system is IB Solar Roof. There are many types of both solar metal roofs and solar flat roofs, using solar PV panels from various manufacturers (though as I said, most do use Unisolar PV laminates).

In this article we will discuss different types of solar roofing systems such as Solar Metal Roofing, Solar Flat Roofs, and Solar Shingles that get integrated with regular asphalt shingles roofs.

Solar Metal Roofing

Most common type of solar metal roofing is the standing seam metal roof with integrated Unisolar PV laminates. Unisolar PV laminates were initially designed to fit in the pan of standing seam panels, with the connection terminals concealed by the ridge cap. Because the connectors or terminals of these PV panels are not UV stable they need to be hidden from the sun, while the rest of the panel is of course exposed to the sun to generate solar electricity.

The benefits of standing seam solar metal roofing include fast installation, easy troubleshooting, lifetime leak free roof performance, and in US, you can get the 30% solar tax credit for the metal roof also, as it is a part of the solar system.

Solar Metal Shingles

Another type of solar metal roofing would be the solar metal shingles roofing. The concept is similar to solar standing seam roofing, but since metal shingles are much smaller, the solar PV laminates have to be adjusted to the size of the shingle. Also, all the terminals must be connected during the installation – if you miss just one, the circle will be broken ans the solar system will not work. Imagine finding the broken link when you have hundreds of not thousands of metal shingles to take of to find on broken connection.

Price-wise, I think that standing seam solar metal roofing is much more viable, as there is substantially less installation labor involved and much less potential troubleshooting, if something goes wrong. Imagine hiring a solar integrator and a professional metal roofer at $75-100 per hour – each – to find whats wrong with your solar metal shingles roof. Even if everything is peachy, the amount of time that will be used to install solar metal shingles is much more than that of solar standing seam roof. The total solar system price will be significantly higher just from all that extra labor.

Bottom line, the choice of solar metal roofing system that you decide to use will be more of a personal preference. Both will work great when professionally installed, and will last a very long time.

Solar Flat Roofing

Main reason for flat roofing materials manufacturers to begin developing solar flat roofing systems was to A) eliminate roof leaks associated with flat-roof solar installations, and B) sell more flat roofing materials, which is their main business after all.

Solar Flat Roofing is a great concept, but has some limitations. First, the angle on the solar panels is flat, so these solar panels will not catch as much sun light as tilted or sloped solar panels. Second, solar flat roofs will be much more effective in warm climates vs. colder northern climates such as New England, as in the winter, flat roofs are completely covered with snow and sunlight does not get through to the solar panels.

That said, the benefits of solar flat roofs far outweigh the drawbacks of solar flat roofs in colder climates. The solar PV panels that are integrated into the roofing membrane, eliminates 99% of roof penetrations, considerably reduces the wight of the solar system and the total solar system price. Not only the solar panels prices are lower for roof-integrated solar systems, you also eliminate the entire rack-mounting system (which costs about $1 per watt of your solar system) – and that is not small beans – you will save about 10-15% off your total solar system cost. Also since the roof solar system weighs much less than regular solar panels mounted on racks, you also eliminate substantial wight, and your building construction costs will be much lees, because you can reduce roof load requirements.

Solar Shingles

Solar shingles are very similar to solar metal shingles described above. The main difference is that they are designed to work with 3-tab or architectural asphalt shingles instead of a metal roofing shingles.

Although the solar shingles may seem as a great concept, please consider the following factor which make them not such a viable option when it comes to solar roofing. Solar Shingles are rather expensive… But all solar is expensive. Biggest problem with solar shingles in my opinion (roofer’s point of view that is) is following:

Solar shingles, just like metal solar shingles, take very long time to install, as each shingle must be connected to the rest of the solar system in series. However, unlike solar metal roofing shingles, there is no room to conceal the terminals under the shingle, so all connections must take place inside the attic space. Holes must be pre-drilled for each shingle, and terminals are fed inside the attic where they are connected.

This slows down the installation process significantly and usually you cannot finish this in one day. If it starts to rain, your roof is toast. There are too many penetrations under solar shingles, and it is very easy for water to get in. Of course there are ways to prevent roof from leaking even if it rains and roof is not finished. You can run the last row of shingles and overlap it with roof underlayment, which will prevent roof leak. Still this makes the total job that much more complicated and costly.

One more thing to consider is the fact that asphalt shingles only last about 15 years and will have to be replace down the road, where as a metal roof will last pretty much forever, or at least a lifetime of your house.

Conclusion: Pros and cons of solar roofing

As you can see, there are many options for solar roofs. Most are lifetime and and will work great. Some will last not so long (read asphalt roof shingles). In general the benefit of solar roofing is that you install it once and forget about it – there is no maintenance, no roof repair issues, no hassle.

On the other hand, solar roofing is more expensive as you are not only buying a new solar system, you are also getting a new roof, and in case of a metal roof, it is pretty expensive – certainly more expensive than asphalt shingles roofing. Even with 30% federal tax credit and some local solar rebates, it is a substantial investment up front. However in the long run it will pay for itself, with electricity generation and lack of roof and interior repairs.

Solar Roofing Resources

Solar System Guide – everything you need top know when designing a residential Solar PV system – positioning of your roof toward the sun, shading and angles of your solar panels, choosing the solar panels and inverter, etc.

Metal Roofing Materials – learn about different metal roof types and which metal is better to use – steel, aluminum, copper, zinc, etc., as well as learn more about metal roofing prices.

Metal roofing is an excellent choice for quality-minded homeowners, as metal roof is virtually the only lifetime roof system that light weight, long-lasting, and most of all – affordable. If you compare prices of metal roof to slate or clay tile prices, you will realize that an average metal roof will cost you only about one third the price of natural slate, while it will look the same or better and last at least as long.

There are many styles of metal roofs and many choices for roofing material – your choices range from galvanized steel / aluminum metal roofs, to premium metals such as zinc, copper and stainless steel roofing. You can choose between a “standard” vertical panel (standing seam) metal roof, or a metal roof made to look as either cedar shingles, shakes, natural slate or flat and barrel tile.

You will also get a wide range of colors to choose from. The result will be such that you will get the look you want with the price you can afford, and the long-lasting performance of metal roofing.

Metal roofing – premium roofing material at down to earth prices:

There is much confusion about the prices of metal roofs, as there is a wide range of metal roof styles and materials to choose form and some will cost a lot more than other. In this metal roofing prices guide, we will show you how much you should expect to pay for different metal roofing systems, and how the choice of metal roofing materials will affect your roofing cost. But before we jump into roof pricing for each type of metal roof, let me clarify one thing: metal roofs are pricey as compared to asphalt shingles roof, but keep in mind that metal roof is a lifetime roofing material and so should be compared to its counter-parts in the roofing market – other lifetime roofs, such as natural slate, clay Spanish tiles, concrete tiles, and lately, synthetic slate roofing.

Asphalt shingles on the other hand are not a lifetime roofing materials and you can expect to replace an average asphalt shingle roof every 15 years. Even the “50 years” or “lifetime” asphalt shingles won’t last more than 25-30 years as they will simply dry out / roast under sun’s heat and ultraviolet rays.





Also we want to mention that metal roofs cost just as much as a cedar shingles roof, but they will outlast cedar shingle by at least 3 times on average, as cedar shingles rarely last longer than 20 years, due to moisture, mold, mildew and moss growth, etc. Also you can get a metal roof that looks just like a cedar shingles roof, at almost the same price.

Benefits of metal roofing:

• Metal roof is a lifetime roofing material, and you can expect an new metal roof to easily outlast your house (when installed correctly). Even the galvanized steel metal roof, which is usually warranted for 50 years, will usually last well beyond its warranty period, unless it is subject to corrosion due to external sources/causes, such as salt-air environment or mixing of different, incompatible metals, such as copper, aluminum or zinc.
• Main benefit of metal roof is that it is made out of the most durable roofing materials available, and metal does not deteriorate with ages, unlike asphalt shingles. Sun’s UV rays have no effect on metal roof performance, with the exception for the paint fading, which happens rather slow and gradually, and goes virtually unnoticed, for metal roofs coated with Kynar 500 / Hylar 5000 coating.
• Metal roofs are light weight, and do not require any special framing to support the wight of a roof systems. Average metal roof weights 50-80 lbs. per 100 square feet, or one roofing square, compared to 250 lbs for asphalt shingles and as much as 800 lbs for slate or tile roofs. Due to low weight of a metal roof, they can easily be installed over  existing shingles, which will further reduce your roof installation price. However there are some exceptions, which we will discuss bellow.
• Metal roofs are Cool Roofs by nature, as they do not store solar heat, and unlike asphalt shingles, quickly cool down as soon as sun goes down. When coated with “Cool Roof” coating, metal roofs will qualify for a $1500 cool roof federal tax credit.
• Metal roofs shed ice and water and are a natural solution for ice dams problems and related roof leaks. Although Ice Dams are more than just a “roof problem”, nearly every asphalt shingles roof will be subjected to ice dams, no matter how well it is ventilated and insulated. Metal roofs prevent ice build up, as any snow and ware will slide off a metal roof. Even when ice build up occurs on a metal roof, continuous vertical panels and interlocking metal shingles design will not let the water back up under the roof and leak inside your house.

Metal Roofing Prices:

Although roof prices differ from region to region, metal roofing prices are more stable and even, compared to cost of asphalt shingle roofs. We will look at metal roof prices based on metal roof type and material. Metal roof prices described bellow, are the going average in Massachusetts, Connecticut and Rhode Island, but there should not be much difference in metal roof cost, where you live, unless the economic situation in your region is very dire. Usually roof prices have direct co-relationship to the cost of living in your area and metal roofs are not exception.

Before we dive into metal roofing prices, lets establish a reference point for which roof prices are given: Our model roof will be a 1500 sq. feet gable roof with one chimney, a ridge and two roof “planes”, as well as 3 bathroom vent pipes. There are also two skylights on the roof and about 50 feet of roof to wall flashing (side-wall flashing). Our “model” roof has a plywood deck with no shingles or any other roofing materials on it and all wood is in sound shape. We will install 3 feet wide Ice and Water Shield along the eaves of our roof and GAF DeckArmor underlayment on the rest of the roof. We also will install 5 snow-guards over each door used in the winter, and over garage doors, and a ridge vent along the ridge.

So here is a basic rundown on roof specs:

• Roof slop – walkable – 3 to 6 roof pitch.
• No tear-off.
• Roof installation to include Ice and Water shield along the eaves / valleys, and GAF DeckArmor over the rest of the roof.
• Roof installation includes Ridge vent cut in and installation.
• Roof installation includes new, color-matching chimney flashing and counter flashing.
• Skylight flashing and chimney flashing for more than one chimney is usually extra, and is not included in the following per-square roof pricing.
• Snow guards are normally installed only over doors which you use in the winter – typically 5 or 7 snow-guards per door. Any additional snow-guards are charge for at about $15 per snow-guard.
• When roof difficulty goes up, the price-per-square goes up. So a roof with many valleys, dormers, side-wall flashing, etc., will cost more, than a simple roof in the picture bellow.

We will list the metal roofing prices for different metal roof materials in the order of low to high price. Also notice that there is a difference in price of steel roof vs. aluminum roof, with aluminum being about a $100 more per square, compared to G90 or Galvalume steel.

Steel shingles metal roof prices:

Steel interlocking shingles is the least expensive architectural metal roof system, though id does not mean that it is “the worst quality”. In fact, steel shingles, such as those demonstrated above, are a very high quality metal roofing system, but cost the least as they are the least expensive metal roof material for us to purchase and a metal roof shingles are the “easiest to install”.

On average, one square of steel shingles will cost you about $800 to install on a simple roof such as the one described above, excluding any tear-off, and other extras such as multiple chimneys/skylights flashing, gutters, leaf-guards, etc. This price includes any one of the three available profiles: Slate, Wood Shingle and Tile.

Aluminum shingles metal roof prices:

Similar to prices of steel interlocking shingles, aluminum shingles will cost $900 per square, which includes the difference in material prices. All other items remaining the same. Aluminum shingles installation is virtually the same as steel shingles, with the exception of using aluminum ring-shank nails and usually not using clips, as aluminum shingles are smaller (1 sq. ft. each) and have a built in attachment “ear”.

Standing seam metal roofing prices:

Standing seam metal roof material costs more to install, and is usually more difficult / time consuming to install if there are any roof penetrations such as sky-lights or chimneys, as the flashing method for roof curbs on standing seam metal roofs is very complicated due to roof design. Additionally, the roofing material prices for standing seam are considerably higher, as the metal gauge is higher compared to metal shingles in both steel and aluminum.





A simple roof with standing seam metal panels will cost about $1000 per square for steel metal roof. As soon as difficulty of a roof goes up, the installation process becomes much more complicated as compared to metal shingles, and the price difference per square  becomes higher than is the case with metal shingles. This is due in part to the lack of a method to install roof staging on a standing seam metal roof, and a need to use the hydraulic lift on most hip roofs, as there is no way to attach a hook ladder on a hip roof.

Aluminum standing seam metal roof will usually cost about $1100 per square to account for material price difference. Also, the snow-guards choices for standing seam roofs offer great range for styles, but also increase the overall cost.

Exposed fasteners (EF) metal roofing – Multi-rib / R-panel / V5 crimp panel / corrugated metal roof prices:

Unlike the architectural metal roofing such as standing seam, exposed fasteners metal roofs cost considerably less, but are also of a much lower material quality and are limited in terms of installation / flashing methods for complicated roofs. EF metal roofs are designed to be a cheap metal roof for farm / industrial / commercial buildings, and are rarely used in residential metal roofing. This type of metal roofing is usually made with a cheap 29 ga steel and acrylic paint / coating, instead of a minimum 26 ga steel and Kynar 500 paint for architectural standing seam. Also the limited flashing method, makes this type of metal roofing a bad choice for complicated roofs. Exposed fasteners also pose a great possibility of a roof leak and will normally require re-sealing and re-tightening in about 10 years, as neoprene rubber gasket dries out and water begins to sip in.

Price of an EF metal roof averages between $600-650 per square. The difference in roof price is due in part to considerably lower quality and cost of roofing material as well as faster, simpler installation.

Specialty metal roofing products – stone coated steel, copper and zinc metal roofs:

Stone coated steel is one example of specialty metal roofing. Although it is pretty common in the south and med-west, it is rather rare in New England, and due to high material costs ad complicated installation, stone coated steel metal roofing is only installed when a specific style of a light metal roof is required. Most common style if stone coated steel roofs is the Spanish tile impressions.

Stone coated steel roofing is usually made form a 24 or 22 gauge, G90 galvanized steel, and is coated with tiny stone granules painted in typical colors of of clay tile roofs installed throughout Southern Europe, with dominating red and orange shades.

Stone coated steel roofs are usually installed over horizontal battens, and installation goes from top to bottom instead of typical bottom-up installation process.

Stone coated steel roofs usually cost about $1300+ per square, including installation of 2×2″ battens, and underlayment. All roof penetration flashing is rather complicated due to design limitations of stone coated steel metal roofs and hence will cost even more than curb flashings for standing seam roofs.

Despite higher than usual roof prices, stone coated steel roofs offer a beautiful look of a Spanish tile roof, at a fraction of the total cost of the real clay tiles, while the roof quality is at lease the same if not better. The relatively light weight of stone coated steel roofs eliminates the need for special framing required to support the weight of real clay tiles.

Spanish tile stone coated metal roof which we installed at Venus De Milo restaurant in Swansea, MA

Copper roofing prices

Copper is rarely installed over entire roof due to extremely high material prices. Copper is usually used for smaller, custom roofs, such as decorative bay-window roofs, curved metal roofs, etc. However if you want to have a copper roof installed over your entire house, the most cost-effective copper roof would be to use copper interlocking metal shingles, which have the same design as aluminum shingles, and are once again, the easiest type of copper roof to install and cost less than copper standing seam.





Since copper is a pretty soft metal, is can be molded and formed to look like almost any type of roof. Copper looks particularly “awesome” when it’s made to look like Spanish tile, especially when the natural green patina occurs on it due to normal oxidation. The Spanish tile copper roofing is by far the most expensive copper roof, when you price it for the whole house. Of course it will still be less expensive per square foot, compared to custom copper roofing.





Copper roof prices:

The least expensive copper roof shingles will cost you about $2000 per square. This number is not very firm though as copper prices are very volatile and have risen dramatically in the recent months (since Jan. 2010). This price includes all flashing made from 16 oz. copper as well as copper shingles which are also made from 16 oz. copper. You also have a choice of 20 oz. copper, but that will bump up your copper roofing cost another $100 per square.

Copper Spanish tile will cost you about $2750 per square, as it is made from 20 oz. copper by default, costs considerably more than copper shingles and the installation of copper Spanish tile roof is also much more complicated.

Any custom copper work will be priced on per job basis as there is really no way to provide standard pricing for custom copper roof work. However, a typical straight panel copper way window will cost you between $2500 and $3000. Any curved copper roof installation will increase the roof price dramatically.

Zinc Roof prices:

Zinc roofing costs virtually the same as copper, though in some cases it is actually less expensive. Zinc roof is usually installed as standing seam, though, custom zinc roofing shingles can be ordered and manufactured as a special order. In general, you can expect to pay $1800-1900 per sq. for zinc roofing on roof sizes over 500 sq. feet.

Metal Roofing Resources:

Use our Roofing Calculator to estimate metal roof prices in Massachusetts, Connecticut and Rhode Island, as well as get free roofing price quote, when you submit a roofing estimate request.

Solar Metal Roofing – Did you know that standing seam metal roof can be combined with a thin-film solar panels such as PV laminates made by UniSolar? Solar metal roofing is the most cost effective way to combine green metal roofing materials with Solar Panels, and get the best price for both!

You can use the Solar Calculator to estimate solar roofing prices based on the roofs size as well as the size of the solar system you are looking to install. Solar calculator will also help you estimate the break-even period and the solar electricity production of your solar PV panels.

References

Metal Roofing prices – a helpful guide to understanding metal roofing prices for materials and labor.

Roofing Costs – related guide to understand roofing prices for common roof types.

Last week, Boston was a host to hordes of roofing sales people, roof manufacturers’ reps and local roofing contractor from all aver Massachusetts and New England. It was the NERCA (North East Roofing Contractors Association) annual roofing convention, where most roofing materials, tools and equipment manufacturers were present, promoting their new products and services.

After being to a few of these shows already, the don’t get any more exciting, but it’s always nice that NERCA sets up up open bars with semi-decent wine, and cheese / crackers / fresh veggies & berries tables. I think for roof sales professionals, these roofing conventions have become a boring necessity as all they do is schmooze with each other and talk about competition. As for me and other roofing contractors, we can always find some new and exciting roofing materials and roofing tools, equipment and services, such as infra-red roof scanners, roof lifts, hydraulic-powered dumpster which can be lifted to the roof level to speed up roof tear-oof and clean up process.
As an Flat Roofs contractor we were there supporting IB Roofs which had a booth there, and I got to meet IB’s new Regional Manager Dana Spurgeon, as well as IB’s local reps in Massachusetts – Jerry Lang and Kevin Laprte (whom I already know of course).

Roofing Equipment presented at Boston Roofing Show:

Besides the obvious and now ritualistic visit to the IB Roofs stand, I wanted to find as many cool, interesting and innovative roofing products at this show, and quickly wondered off, to explore the unknown. My first find was an excellent new automatic hot-air welder by Leister – the new Varimat V2.

This new auto welder, unlike the original Varimat V, has increased and elongated nozzle, and much more powerful fan built into its heat gun, which allows siginificant increas in welding speed from 15 feet per minute for the Varimat V to a maximum 39 feet per minute and realistic 30 feet per minute for the new Varimat V2!

The new Varimat also has new computer controller which lets you save your setting into profiles of various welding speeds and temperature, which can be used for winter and summer roof installation and different roofing membranes, such as TPO roofs and IB single-ply PVC roofing. This new Leister automatic welder is the most advanced tool in its class, and can dramatically speed up roof installation time on large commercial roofing projects. However it comes at a premium price-tag of about $8000 before taxes, requires a more powerful, 6800 watts generator, and of course heavy gauge 240V extension cords, which can easily make the total price for this unit to be over $11000-12000.

Another interesting piece of equipment I found is the hydraulic-powered dumpster lift, which can be driven right up to the roof line and will let roofing contractor to dump old shingles or other roofing materials right off the roof, eliminating clean up, using tarps to cover the exterior walls of the hows and the grass, as well as roofing nails all over your yard, at the end of the day.

Another really interesting piece of roofing equipment is the automatic plates and fastener driver from OMG Roofing. Last year, at the roofing show held at Foxwoods in Connecticut, OMG Roofing demonstrated such unit for flat insulation plates, but did not have one that would quickly fasten the barbed plates used to hold down single ply roofing membranes.

Bellow you can see a video of this plates and fasteners driver in action, attaching a piece of PVC roofing membrane to an ISO insulation over wooden deck roof assembly: Once again, this unit uses barbed plates that are 2 3/8″ in diameter and are made to mechanically attach single ply roofing systems to the roof deck.

Solar Roofing products presented at Boston roofing convention:

Soprema Roofing also had a pretty nice stand where they displayed new Modified Bitumen roofing systems with cool roof reflective layer on the top and SopraSolar roof integrated solar systems. This solar systems, just like the IB’s Solar Wise solar roofing system, uses the UniSolar thing film Solar PV panels, adhered to the roofing membrane.

This new SopraSolar system is a much cleaner installation than Soprema’s original roof-integrated solar systems. The roof integrated solar PV systems are more expensive than regular solar systems, but they offer completely water-tight installation of the roof and solar panels and virtually eliminate roof leaks – calculate solar system cost using Solar Calculator – a free tool that allows you to estimate solar system size, number of kW and how many solar panels you will need as well as solar payback period.

Solar Roofing Tiles:

One more cool roofing product, also using UniSolar thin-film solar panels, which is made in Pennsylvania, is a Spanish roofing tile product, made to easily be installed with clay tiles and provide roof integrated solr panes without any roof penetration or solar mounting racks:

Other interesting roofing materials and products:

Soprema also had a demonstration stand showcasing its PVC roofing systems coated with natural copper, which would actually turn green and the patina process begins. This PVC roof systems also comes with PVC made ribs, so the complete roof system imitates Copper Standing Seam metal roof at a fraction of the cost.

Another interesting product, this time for the sloped roof is a roof vent, which can be installed along th roof eaves, when your roof does not have soffit vents, and improve ventilation of your roof, which will increase the time that your roof will last, make your roof deck last longer and help prevent Ice Dams on your roof.

Ultimate car for the roofing industry:

There was also a rather unconventional vendor present at this year’s roofing convention, who designed a vehicle specially for the roofing sales professionals. This new hybrid concept car features high gas mileage, wide wheel base and extra cargo space for all your roofing samples, brochures and equipment. Unfortunately there is no roof rack on this car, so you won’t be able to take a normal ladder with you, but you can always use a folding telescopic ladder, or as most roofing sales people do – measure the roof off the ground

This new hybrid car is rumored to be a replacement for Toyota Prius, which recently has had a lot of problems with it’s brakes systems and sudden acceleration. This new “bucket” car is supposed to eliminate most problems of a Prius and provide many additional benefits, together with great gas mileage.

As I’m writing this, the 2009 Solar Decathlon in Washington, DC is nearing its completion. Twenty teams from around the globe are competing to build the best Solar Home, judged in ten different categories, including: architecture, engineering, net metering, living comfort as well as others. This year, Massachusetts – home to some of the  greatest colleges and universities in the world – is represented by Team Boston - the joined efforts of Tufts, Boston Architecture College and a team of volunteers, all with the common goal to create green and sustainable home designs that could be readily available and affordable for actual home buyers and home builders. You can read my 2009 Solar Decathlon Review with pictures and videos I took there during Columbus Day weekend.

Cool Flat Roofs and IB Roof Systems are proud sponsors of Team Boston’s solar home.  We provided the project with IB flat roofing materials (provided by IB Roof Systems) and a professional installation, as well as last minute roof design changes, and modifications to roof penetration placement and drainage setup.

The Boston solar home construction is all finished, the Solar Decathlon competition is almost over – the houses will be disassembled and and transported to their final placements. Team Boston solar home has already found its buyer in Cape Cod, where it will be available for public tours. Building this home was a bit less glamorous, and here I will tell you about our part – the installation of a flat roof.

Roof Design:

The roof was designed to allow for house to be transported in 3 sections, and to host 3 rows of solar panels, as well as collect all rain water. The house design team had to work really hard to make all three major requirements work together. The roof and the house were separated into 3 different sections, with separating parapet wall inside and around the perimeter. To avoid roof penetrations and as a result – roof leaks, the solar PV and hot-water racking systems had to be placed on top of parapet walls – both interior and exterior.

The roof drains and all roof penetrations had to be placed so they would be away from future solar system racking steel beams. The roof itself was designed so that all water in each section, would run toward the roof drain, with an overflow scuppers as back-up drains.

We utilized the 1/4″ (1/4″ rise to 1′ run) tapered insulation system, which would go from 1″ at the lowest spot to 5″ at the highest point. The roof drains were place at the lowest points of each roof section, while all roof penetrations were moved to the highest points on the roof.

Roofing Material: Because of multiple inside corners and roof penetrations, IB Flat Roofing PVC membrane was chosen and the best roofing system for the job, as it allows for all roof flashing components to be hot-air welded together, which eliminates a possibility of roof leaks due to seam failures. Even if the roof would be damaged during the construction process (there was constant foot traffic on the roof, after we finished installing it – plumbers, electricians and Solar PV installers), it would be easy to repair – as easy as welding a patch over damaged area – a one minute repair.

IB Flat Roof Installation – Day 1

Due to scheduling and timing matters, all construction on Boston Solar Home was performed on Fridays, Saturdays and Sundays of each week. We started installing our roof on a Sunday, after 2 days of rain, and as we pulled up to the construction site at Tufts in Medford, MA, it was still drizzling, and the team members were vacuuming and pushing water off the roof. This was a challenge by itself. After pulling the tarps off the roof, there were about 4 inches of rain water trapped between parapet walls of the roof and tightly sealed moisture resistant roof decking. Water was slowly dripping inside the house, but a major part of it was still on the roof. Two holes were drilled through the roof sheeting in the overhang section, where the roof drains would soon be installed. The water quickly drained over the grass, but a third section of the roof had to be manually cleared of water with a wet vac and push-brooms.

Installing Roof Insulation: As we unloaded our tools and materials, the guys from team Boston, were finishing the roof drying process, the drizzle stopped and we were ready to start installing roof insulation – a tapered insulation system that would span between 1.5 and 5 inches. We used different thickness ISO insulation board, starting with 1″ at the bottom, and going up / leveling it off with tapered and straight insulation. All insulation was attached with heavy duty, corrosion resistant screws and plates. At the highest point the R-value of the insulation would be 30-R (6-r value per 1 inch of insulation). Additionally, there are approximately 12 inches of sprayed foam insulation between the rafters, which makes the roof of this solar home, super insulated and eliminates the weakest point in the house, and when it comes to heat loss, as most heat escapes through the roof.

Installing IB Roofing Membrane: Due to weather conditions, we had to start work late, and it was apparent that we would not finish the whole roof in one day – even with the help of about 6 architecture students from BAC, and Tom Paisley – a green builder from Middleboro, MA, who introduced me to people from Team Boston.

We were able to finish one section of the roof completely, including all the parapet wall flashing and inside corner detail, installed a temporary roof drain, as well as welded all the seams. Since the plumbing for the IB U-flow drains was not in place yet, we installed IB membrane drain liner, and fitted it into a temporary PVC pipe. On the second section of the roof, we only had time to lay down the field sheets of membrane and a drain liner, and left the parapet wall flashing and corners for next day.

IB Flat Roof Installation – Day 2

As we arrived to the job site the next morning, the sun was beaming down on us, and the temperature was nearing 95 degrees – there was not even a sign of rain from previous days.  I was so happy that the roofs we install are white and barely gain any heat form the sun – otherwise it would be near impossible to work in these weather conditions. Nevertheless, I went through at least a gallon of water that day.

Architecture students and volunteers were laying down the insulation as I jumped onto the roof, and started planning out the membrane layout, to minimize waste. Since IB Roof comes in 6 feet wide rolls, and the width of the roof sections was about 9-10 feet, there would be 2-3 feet of material I had to cut off. We would cut it in half, and use it for parapet wall flashing.

Once all insulation was in place, we could finish installing the IB Roofing membrane and welding all the seams to make the roof completely watertight. In total we had to flash 12 inside corners (and later, as we were doing the overflow drains, we had to install 6 outside corner flashings), 3 through-roof IB U-flow drains and 4 through roof penetrations: 1 for the bathroom vent and 3 others for Solar PV and Solar Hot Water hook-ups.

All seams were welded with the Swiss made Liester hot-air welding equipment which is a de facto standard in the thermoplastic roofing world. For long seams we used the Liester Triac Drive – an ultra portable semi-automatic welder which can make a life of a roofer much easier. When we need to weld a small section of a seam, the hand welders are perfect. But when it comes to longer seams, doing it by hand become, if not problematic, then very painful - literally. Hand welding can put a lot of stress on your wrists and that is why we invested heavily into automatic welding equipment.

Solar Home Roof installation video: Welding IB roof seams

One major obstacle we still had to solve was the the fact that Solar Home is built to be transportable in 3 sections. The IB roof membrane would have to be cut along the inside parapet walls, to take the house apart, and when the house is put together, it would have to be watertight, and preferably without having a roofer and hot air welding equipment on site. Although the parapet walls would be copped with aluminum parapet caps, it would not be a sufficient way to keep the house watertight and leaks free – maybe just for a short period. But the team could not afford to have roof leaks in the middle of Solar Decathlon competition or after. We had to figure out a way for the roof to be watertight not once, but every time the house is transported and put in place, without additional welding. This we took care of later, once the Solar PV and Hot Water panels rack system was installed.

We finished day two of roof installation as it was getting dark, and most architecture students had already left the job-site. Now we had to wait until the solar panels were ready to be installed.

IB Roof with Solar PV and Solar Hot Water panels – Day 3

Once the IB roof was installed and Boston Solar Home was watertight, we took a little break and concentrated on our everyday roof installation. In this time, the Team Boston was hard at work on the interior of the house as well as getting ready for the final stage of the roof installation – Solar PV and Solar Hot Water installation, which would use a Steel / Aluminum Racking systems bolted to the parapet walls.

By the time we got to the job site on the 3rd day of roof installation, the mounting racks were already in place and some Solar PV panels were also installed. We had to work around them and in some cases actually move the racking system and Solar Panels, so we could get into tight spaces.

We had to install all three IB u-flow drains (which due to their size did not fit between the solar racking system), pipe penetration flashings for exhaust pipe and solar electrical and plumbing hook-ups. We also had to install the over-flow drain scuppers and as I discussed before, we had to figure out a way for the house to be watertight after it was transported to Washington, DC fro the Solar Decathlon and to its future owners, preferably without roofer involvement.

We decided to weld a wide strip of IB membrane over parapet walls – one side would be welded while the other would remain not welded, but flipped over to the other section. This way the cut between house sections would always be watertight and with the addition of parapet caps, the wind driven water would never penetrate the roof. W also had to figure out how the “T” join of 3 house sections would work, and the overlapping joint covers were installed, each welded to its own section of the house.

As we finished installing all roof flashings, the house was all watertight and almost ready for the transportation to the Solar Village in Washington DC, for 2009 Solar Decathlon. There was still a lot of work to be done, like all the heating, interior, and other construction work, but our part was over. I did plan to volunteer some of my time to help team Boston with building this beautiful home, but as the busiest time of the roofing season rolled on, I could harly find time for my full time job. I did not see the Boston Solar Home until I actually went to DC for the Solar Decathlon, during the Columbus Day weekend.

Quick highlights of the Boston Solar Home:

• Size – approximately 800 sq. ft. Competition regulations limit solar home size to 800 sq. ft. and most contenders, except one, built their homes to maximum allotted size.
• Solar PV system size: 6.4 KW DC, with individual mini inverters to maximize electric output, and minimize shading losses.
• Wall insulation: 2 inches (13-r)  of ISO board with aluminum foil (more insulating value than regular ISO board) and 8 inches of in-wall insulation.
• Trombe wall – a liquid-filled solar thermal mass windows, that collect and store solar heat during the day and heat the house at night.
• Solar Hot Water – 5 hot water panels that provide heating and hot water for the house.

Because of size limitations, each team had to use the most efficient solar panels available on the market (not development products). This posed additional obstacles for the designers and builders, and forced the use of rack-mounting system to house solar panels. If the house was not limited to certain size, the use of IB Solar Wise PV system – the building integrated solar PV modules built by Uni-Solar, would greatly reduce the final cost of solar system and simplify the installation. IB SolarWise eliminates the need to use a rack mounting system as it is a thin-film solar system adhered to IB patented membrane – Solar Shield – which distributed the heat gain of solar panels and prevents delamination,  which is often the case when UniSolar panels are installed over rubber roofs of TPO single ply roofing systems.

Getting IB Roof and IB Solar PV systems installed in MA, CT and RI:

If you are interested in having IB PVC roofing membrane or IB SolarWise PV system installed on your home or business, feel free to fill out our online roofing estimate form to get free price quote. You can also use our interactive roofing price calculator to estimate the cost of your roof replacement and compare IB roof prices to those of EPDM Rubber, Modified Bitumen and Tar+Gravel roofs. We recently updated our calculator to account for smaller sized roofs, and to also include options for chimney or skylight flashing, parapet wall flashing and other roof penetrations.

You can check out the roofs that we have installed all over New England by looking at job profiles, which we regularly post for each state:

Flat roofs in Massachusetts

Flat roofs in Connecticut

Job profiles for RI and NH will be posted soon.

The word on the “roofing contractor street” is such that a large PVC roofing manufacturer has problems with their Roof-integrated Solar PV systems. Apparently, the way they designed and installed these solar roofs, the electrical wiring which  connects Solar PV panels to the inverter and essentially the Electric Grid, is overheating and poses serious risks of fire. Since this information is still in rumor stage, and I doubt there will be an official announcement or acknowledgment of these, I for many reasons cannot name the manufacturer, the specifics of the problems or the source. However, there is evidence that it is real. If you are a large roofing contractor in Boston, MA area or in the rest of New England, you are getting the roofing bid lists such as the Blue Book. We do not as large commercial and government roofing jobs are a little out of our league, and we get plenty of work without paying huge sums of money for these bid lists (it costs anywhere from $3000/year to get periodic updates). However, in the last 3 weeks I’ve been contacted twice by two different gentlemen from Suffolk Construction. Basically Suffolk is arguably the largest GC in Boston area with $1.57 Billion in sales in 2008, have over 800 employees and are rated #313 of America’s Largest Private Companies by Forbes.

The picture bellow, shows a Solar roof produced by IB roof systems. This roof does NOT have overheating problems, and is intended to demonstrate what Solar Roofing is.

In any case, the two gentlemen from Suffolk, asked me to bid a new job in the pipeline of roof bidding lists:  A 4,000 squares (400,000 sq. ft.) on the IRS building in Andover, MA, and also they wanted 500 KW solar PV system that would be roof integrated – essentially they were interested in out IB Solar Wise PV system which in some ways is similar to the one above, but without the wiring overheating of course The similarity is in the usage of the UniSolar Thin-Film PV laminates. Other than that, all other components of these Solar Roof systems are proprietary and are very different. So how are the two evens connected? It is my understanding that the Solar roof described above, was originally specified for this IRS roof, but because of the problems, they are looking for the one that works. Because IB SolarWise is about the only Solar Roof systems out there that does not have any problems with it, Suffolk contacted us on two occasions. Aside from the cable overheating and fire hazards, most other flat roofing manufacturers that wanted to use their roofs with UniSolar PV laminates, ran into problems of solar panels delaminating form the roofing membrane. IB Roofs took their time designing the IB SolarWise PV system, and developed a special membrane called IB Solar Shield which is designed to provide excellent adhesion between the PVC material use in IB roofs and the Butyl adhesive on the UniSolar pv laminates. This eliminates the potential of delamination that most (if not all) other roofing manufacturers are facing. The earlier version of IB SolarWise used the solar panels made by Open Energy of California. Later UniSolar panels were chosen as default integrated PV system because it allows for greater flexibility for the contractor, system designers and the customer.

Today’s IB SolarWise PV systems are made in the following way: IB takes 6×19′ Solar Shield membrane and placed 4 UniSolar 136 watt modules using a special process which insures the proper bond between two products. Then the whole IB Solar Wise module gets welded to the already installed IB Flat Roof. IB uses regular UniSolar modules with the connectors facing the outside of the module. Although this requires special housing to protect the connectors from UV rays, it eliminates the possibility of cable overheating as all wares are exposed to the air and are ventilated. This makes IB Solar Wise the best solar-integrated roofing PV system. If you are looking for more information about solar roofing in general or want to know if solar will work for you, we recommend that you read our Solar PV design & installation guide.

Electricity of the 21st century.

Do you know how your electricity is generated? For a long time I kind of knew, but was too lazy to actually ask my father, who is a physicist, what exactly is going on in the power plant. Now it boggles me to live with the fact that in our modern time when an all-inclusive communication and Internet device (iPhone, BlackBerry, etc.) is smaller than a deck of cards, we still use 19th century technology and basic principles to generate our electricity. Once you actually give this idea a thought, it becomes a shocking notion that our best minds were not able to create a better way to create electrical power, than to burn coal and natural gas – two most commonly used sources of energy to create electricity.

Just in case you were wandering, coal or gas is BURNED to heat up water which then becomes hot steam and drives the turbines. This is a basic principle and the actual process is more complicated, but even the “sophisticated” nuclear power plants work in the similar manner.

Note: I did know that electricity can be generated in the old fashion way, but I actually thought that there was some kind of a mechanism to directly convert energy stored in gas / coal / oil directly “into” electricity, instead of emulating the old steam-engine – oops… It is a shame that our 21st century society is still burning fossil fuels to make the turbine spin.

Aside from from the fact that we get our electricity the same way as before WW I, natural gas, oil and especially coal are extremely dirty fuels, emitting dangerous pollutants which affect our the environment in such a horrible  way that just a couple of generations from today, our children may not be able to enjoy the outdoors the same way we can today. I won’t even start about the climate change and global warming. On top of everything mentioned above, humanity is quickly approaching a world-wide energy crisis. Our oil reserves are getting depleted, and if you believe in “Peak Oil” theory, we are about to approach a pick of the curve and it will only become more scarce and prices will keep on rising.

Although coal is very abundant, it is also becoming more expensive to mine and delivery once again involves burning petroleum based fuels, creating more and more pollution. It is obvious to most intelligent people (except those heavily invested in oil, coal, cars, etc.) that we need a clean, renewable source of energy. Despite what may seem like a rhetoric about renewables, I do honestly believe that this is the way we will power our world. However, the renewable energy must be affordable and/or competitive with current sources of energy.

Why Solar?

So what is the answer – what is a modern and clean way to generate electricity? Well, there are a few, and the most popular ones are Wind and Solar. My personal favorite is solar and here is why.

Wind Turbines requires lots of open space and lots of (you guessed it) wind to work effectively. Although wind is a great source of renewable energy, and unlike solar can work at night, it is not “customizable” or adaptable for the urban environment. There is just not enough space or wind in the city.

Solar on the other hand works just as well in city and in the country side. All you need is southern exposure with no or minimal shading. Solar can be installed on a roof a sky-scraper, on the ground or even on a roof of a car. Solar is also a scalable systems, and you can add or remove PV panels and/or inverters at any time. The bottom line is such that solar photo-voltaic power generation is much more practical, and can be implemented where the power is needed. Besides that, both ways of getting “free” electric power from renewable sources are great. Given the notion that solar is more practical and flexible, lets get to the solar PV systems design and implementation.

Getting solar for your home or business.

Despite all the positive aspects of solar, it is expensive – VERY expensive. Additionally, not every site is suitable for a solar system installation. Therefore, if and when you decide to get into solar, the system must be designed and installed to operate at maximum efficiency, to offset its high costs and speed up the pay-off time.

Step 1: Gathering information about a perspective site for the solar project and how much of solar electricity you will need.

As mentioned before, the first step in determining if a solar system shell be installed, a basic site survey must be perfored. Sinse most solar PV systems are installed on roof tops, the basic requirements for a site survey ar as follows:

• The roof plane where the solar system would be installed must have a southern exposure with some variations to the east and west. You can figure this out with a simple compas.
• There should be no shading from trees and surrounding buildings and structures to achieve highest sun light exposure. This gets trick as sun has a different angle to the earth during winter and summer months.  Thus, even in the winter, when sun is at its lowest point, solar panels should have unobstructed exposure to it. Best way to determin where your shading is throughout the year, is to use a special tool called “pathfinder”