We performed this PVC roof repair in Needham, Mass. in October 2011. This was the second time we repaired this 25+ years old Sarnafil PVC flat roof in the last two years. The first time we fixed this roof was exactly two years ago, in October of ’09 – check out our first PVC Flat Roof Repair overview, which covers this roof in particular, and nuances of repairing old PVC flat roofs in general.
Quick Overview of the First Repair
In October of 2009, we fixed this roof for the first time. A contractor was doing some fascia repair work there, and threw some tools onto the roof, creating a hole in the old PVC membrane. We repaired it using new IB PVC flat roofing material. First, we cleaned the old roof with warm water (to remove all dirt and small debris). Next, we rubbed it with acetone and a rough brush, to clean the membrane thoroughly, so the new patch would weld nicely. Then, we welded a PVC patch over the hole, which sealed the roof.
Old patch next to 2 new patches:
The Second Repair
This time around, we found 17 new holes located in different spots throughout this roof. The origin of all these new holes was most likely falling branches, that cracked the brittle surface of this Sarnafil PVC membrane. Typically, small branches do not penetrate a membrane roof – they just bounce off of its surface. But, this roof had gotten pretty stiff over the years, and became easier to penetrate, especially in cold temperature.
PVC Roof Repair Process – Preparing Roof Surface For Patch Welding
We used the same approach to fix this roof, as in the original repair call, though this time around it was much easier to do and went much faster than the first time. It rained the night before we came out, so the thick layer of dirt on the roof got soft from being saturated by rain water, and the roof was much easier to clean.
After removing small water puddles with a squidgy, we used a rough plastic brush to scrape off the remaining dirt, and a small squidgy to clean off the repair surface. Then, we poured acetone over the repair area, and let it sit there for a minute, so it would get deeper into surface dirt, that did not not come off after brushing. Then, we brushed each repair area again, now with acetone over it, and wiped it clean with rags. The surface was now ready for welding a new PVC patch.
Welding a PVC Membrane Patch To the Old Roof
Once the repair area was cleaned, welding patches was a breeze – we set our Leister hot-air welding hand-gun to 7.5 (temperature setting of about 500 degrees Celsius / 930 degrees Fahrenheit), set the patch in place by doing a tack weld directly over the roof penetration, and then welded the patch in place, all around with a 2″ silicone roller (see video above).
Each patch welded in nicely, and the old roof would not blister (condition that we observed during the first repair, when I used a temperature setting of 8 – slightly higher than this time around). When we did the first repair on this roof, the ambient temperature was much colder, so I needed to push the welder temperature up a little more.
Additional Findings, and My Thoughts On Doing Roof Repairs On Old PVC Roofs
When doing one of the patches, I cut out some membrane to check what was below this PVC roof. I found a 1.5″ thick fiber-board insulation that was soaked with water. Also, when walking on the roof, you could feel the insulation was wet / mushy, which means most of the insulation underneath the membrane is wet. I also found a granular surface rolled asphalt-type roofing membrane (most likely 90# rolled roofing or granular surface modified bitumen flat roofing material). This granular surface roofing is what kept the water from leaking into the house, after it saturated the insulation.
At this moment, we are considering options on how to deal with wet insulation under this no-longer leaking PVC roof. One option is complete replacement, which is rather costly – about $6000 (you can use our online roofing calculator to estimate approximate flat roof replacement prices). Another option is to install four or more IB two-way air-vents, which in time will allow this roof to dry out by itself. This would be a time consuming process though, but fortunately there are no big leaks in the second (granular) roof, which I assume the original contractor installed as a second protective measure, in case the roof does leak (this was a new construction addition, at the time when the original PVC roof was installed, and not a second layer of roofing).Adding air vents would be a more economical solution for the homeowner than complete roof replacement.
I also recommended the homeowner to cut the trees that are directly over the roof, which will eliminate falling tree branches from damaging the roof in the future. The trees should be cut regardless of which approach the homeowner chooses to eliminate wet insulation.
All in all, I believe PVC membrane is an excellent choice of roofing material for flat roofs, as it really lasts a long time, and is very easy to repair. This repair job took 3 hours to perform, and cost $475, with materials. If your flat roof (Rubber, PVC or TPO flat roof) leaks, and you live anywhere in Massachusetts, Connecticut or Rhode Island, contact us for an inexpensive repair solution for your roof – fill out an online form to request a flat roof repair in MA, and extend the life of your single ply roofing membrane for as little as $375, avoiding costly replacement.
Flat Roof Installation in MA – If it’s time to replace your flat roof, we provide roof installation services in MA, CT and RI, and use IB PVC flat roofing material for all our new roof installations.