I think the only subject I asked about that you did not discuss was the differences in susceptablity to hail damage between flat roof material choices. I wonder if large hail stones may discount PVC as the best choice is some areas of the country.

I’m glad your starting point endevor is to provide your customers a long lasting maintenance free roof that is the least expensive choice over the long term.
That is real care, respect, Equality and love for your fellow human.

Again thank you for your really great site and the opportunity to openly discuss.

Jim mcdaniels
Colorado springs co 80905

I will start off by saying that when EPDM rubber roof can be installed as one piece (as is the case with your garage roof), that I do not see anything wrong with it. In fact I do mention this on our site. But when a roof is more complicated, and nearly flat (e.g. no slope for water to run off), the glued seams disadvantage becomes a problem in relatively short period of time.

I did mention seam failures within just one year of roof being installed. While this is not common, it happens often enough, and especially on residential flat roof with rubber membrane. On average, seams last about 7-10 years when installed correctly, and using peel-and-stick seam tape, flashing material and cover tape where required (do not bee confused by the name peel-and-stick, as it is actually the better way to install rubber roofs, as compared to older splice adhesive or black glue).

Still, most rubber roofs that we come across, fail within 1-9 years from installation. And one year seam failure mark is actually more common for us, as we often replace residential flat roofs that were installed by hack roofing contractors.

As for EPDM rubber roofing lasting 40 years – that is true in some cases, but, you need to understand that rubber membrane is not what fails – it’s once again, the seams. And seams on these 40 years old rubber roofs have been re-glued at least once or twice and later, as rubber roofing industry began switching to peel-and-stick accessories, the seams we “re-seamed” using first the 6″ inch cover tape and later ans these seams begin leaking again, a 12 inch cover tape is used on top of 6″. So yes, membrane does hold, while seams fail and require repair. When it comes to rubber roof repair, it adds to the total cost of the roof, and not to mention interior damages and wet insulation.

As for the Cool Roof – a black rubber surface does not really help to “heat” the building as in the winter cold does not enter the building or home – the heat escapes. And when it’s cold outside, and there is sun out, the roof is still pretty cold, and it can be covered in snow, so the sun does little to help heat the building. Cool white surface of PVC and TPO roofing, does help tremendously in the summer. Imagine this: on an 85 degree day, temperature of white roof such as IB, only goes op to 90 degrees and you can put your bare knees on this roof and not get burned. Black rubber will go to almost 160-170 degrees and you cant touch it with bare knees for more than a couple of seconds – it becomes painful. I tried both!

And why would you coat a perfectly good black roof, instead of going with PVC roofing? There is no price difference, when yo add the price to install a rubber roof ($4-5 per square foot) plus the white roof coating ($1.5-2.50 / sq. ft.). Coating is a whole different subject in itself – you need to clean the roof and put primer and than at least two coats of either acrylic coating (chepaer and not as long lasting and also, not waterproofing) or Urethane coating which is more expensive.

All in all, taking into account all of the above – roof repairs, interior repairs, hassles to deal with leaks, coating the roof, etc., it makes much more sense to go with more expansive PVC roofing, instead of rubber roof (imho), and especially so for homeowners. I say homeowners, because certified rubber roofing contractors rarely install residential roofs, so you as homeowner, usually end up having an untrained roofer who only installs asphalt shingles, doing your flat roof. I see too many residential rubber roofs failing for this to be a coincidence.

As for you – I think you did the right thing buy putting rubber on your garage, as it is a single piece with no seams and no flashing.

I am an owner of a flat roof detached garage and needed a replacement roof. I found your website very very helpful, but ended up going with a EPDM black rubber roof because my handyman is helping design a deck system to place on top and we are on a budget and e-bay sells the EPDM for an ok price and we were able to purchase one sheet to cover the entire roof with no seams and we were able to use wood trim to terminate etc. so we greatly reduced our materials cost.

After much reading on the net, I get the feeling you paint a true but skewed picture of the EPDM and PVC advantages and disadvantages. If this is true I hope you adjust your information accordingly to show a clearer picture of their comparison unbiased.

You talk about the EPDM seams and what not having such disadvantages indicating that the seams fail around 1 year….however,
I did find some on the internet stating these roofs installed over 40 years old are still working, that the black roof can help heat in the winter, that white paint coatings can be purchased to make them white for summer heat reflection, that they have improved the EPDM formulas, that the PVC is much more expensive, that the PVC and TPO are very susceptible to hail damage (hail damage is the reason my insurance company is paying for a new roof to replace the old rolled asphalt).

I concluded that I am too poor to have a PVC roof and that in my area the hail is a great concern.

Thank-you

Jim