Tar and Gravel Roof Leak

Case Study

1. Finding a leak is not an exact science. It’s complicated even more when the roof is not visible due to excess water. This particular leak was leaking badly. We start off by sweeping the areas of the drip location. It’s best to sweep an area about 8’ x 8’. This doesn’t get rid of the water but it removes the loose gravel, giving us a better view of the true roof, and prepares us for our next step. Now what that step is not something I particularly want to divulge. It’s my secret weapon and process that allows me to be a high percentage leak finder.

2. Once the weakness is found we pour a bentonite clay compound onto the area. This clay turns into a thick slurry and stops the leak! It becomes impenetrable to moisture. Of course the clay will only work if it is placed over the true cause of the leak. Again. This is where my experience is a factor.

3. It took 4 good sunny days for this roof to dry off where we able to return and install our permanent torch on patches. The process for permanent patching is once the clay is shovelled off we need to expose the true membrane of the tar and gravel roof. that is expose the tar paper or tar felts as they are known. this is achieved through a process called spudding. We scrape the rocks, that are originally set in tar, off to expose the tar paper. This provides us a smooth surface to apply the torch on patch to. Remember, substrate preparation is very important in any process. We then aim our torch to the spudded roof and “burn” any other impurities that may be on the surface. Once we’ve done that, it is time to put the new patch down.

4. We use what is known as a base membrane for our patching process. It’s a piece of torch on without granules on it. It’s got a thermo-fusible layer on both sides of the sheet. This allows us to “butter” the perimeter edges of the patch to ensure the bond between patch and roof is the best it can be.

5. Patch #2 is torch applied, fully bonded and water resistant.

Customer:
Project Completed:
Type of Roof: Tar and gravel
Materials: Torch-on patches
Location: Annacis Island

As leak detectives, we started this project as any other, locating the problem. This one was a gusher.With the leak located, we poured a bentonite clay compound into the area.

Now once the leak has been proven to be stopped we need to remove the clay and apply a more permanent patch to the roof. If the clay is left as is, it is will dry up in the middle of summer and blow off the roof. I’ve seen clay drops stop a leak for several months but that is an exception to the general rule. We like to get on the upgrade process as soon as possible. That allows the building owner to do whatever is required on the inside, to bring it back to the way it was before the leak, as soon as possible.

We were 100% successful on this job site. We stopped the 2 leaks on our first visit and our permanent patches have held the water our since.