Water Leaking into Home through Siding: New Residential Flat Roof

We were out in Central London Ontario again this past week, people must be noticing our trucks driving all over London this summer!

We were called out to a residential home. The client reported their flat roof, which was located over their kitchen and living room area was in rough shape. They hadn’t reported any major leaks, however they did say that during the winter or spring, the ice and water build up on the flat roof appeared to be coming into their siding.

This was a 300 square foot roof, and it was an interesting one, as it was essentially two roofing systems cohabitating together, which the client wanted both removed and a new flat roof installed.

On the top there was a brittle 4ply modified bitumen roof system. Then underneath that was pea-stone gravel and felt board. Our job was to remove it all, clean up the roof, check the roof structure for any water damage, and replace any of the damaged wood. We also needed to deal with the reason the siding was leaking.

As we tore off the roofing system, it was almost totally soaked, which was interesting as the roof looked very dry from the surface level. The fibreboard was saturated, when we picked it up during the clean up it was dripping water. Once we got the debris off, and cleaned the wooden deck completely, we began our inspection.

The felt that was part of the roof may have been protecting it, which was fortunate for the owner as we only had to replace a few pieces of plywood, and rebuild some of the fascia board. There was some rotted wood we found around the scupper which we had to replace, however all in all the wood was in good condition

We removed part of the siding to check for the reason for the leaks, and we found it very quickly – the flat roof tie in to the wall had no backing at all, just fibreboard. So we had to cut up plywood and create a proper backing / substrate to put the membrane on to create a proper long lasting water tight detail.

We always remove siding or shingles to tie in our membrane to an existing exterior material, and we typically do that for 1-2 feet to tie in. This prevents ice and water from going up underneath the siding and into the home – this is a critical component that a lot of flat roofing companies miss, as its a time consuming process. However at Legacy Roofs, we go the extra mile to make sure the job is done properly. During the project, the client mentioned that this was something they had experienced in winter with ice and water going in behind the siding.

The deck is tapered in a great way to get the water off the roof, in the middle of the project it rained onto the wood deck, and there was no standing water, so whoever framed and sloped this flat roof knew what they were doing (which we appreciate!). On this job we lowered the perimeter wall so that all the water had no restrictions shedding off the roof

Once the base sheet was down we bent up new metal flashing in a colour to match the home around the perimeter, then finished it up with a brand new 2 ply modified bitumen system.

The owner has a beautiful brand new flat roof that they can rely on for years to come!