Elastomeric membrane maintenance

Your part, feet on the ground

Do not go up on the roof, even if it is flat and access looks easy. The danger of falling is very real. You still have places to observe from.

• The top floor. Look at the ceilings and the tops of the walls. A stain or paint that bubbles points to water.
• A window that overlooks the roof, if you have one. Note a pond that lingers or a flashing that has moved.
• Around the building. At the bottom of the downspouts and along the walls, water running outside its usual path calls for someone to come look at the roof.

Photograph what you see and note the date. These photos will serve as a starting point. On the roof, we examine the whole elastomeric membrane, and your notes tell us where to look first.

Three bad ideas that seem good

• Attacking the ice with a pick, an axe or a metal shovel. The tool gouges or punctures the membrane, and no one should go up to break ice on a roof, whatever the tool.
• Patching with tar from a can bought at the hardware store. The product hardens, splits, and makes a proper repair harder.
• Using a pressure washer. The jet strips the granules and can lift the seams.

The visit schedule

In spring, once the snow is gone. The roofer checks what winter left behind: seams worked by frost, flashing pushed by ice, debris.

In fall, once the leaves have dropped. The roofer clears the drain before the first frosts.

Add a visit after a strong wind. Add one as well when another trade has been working up there. Whoever installs an antenna or an air conditioner can scratch or puncture the membrane without noticing.

What we look at up there

The drain. We pick up leaves, twigs and plastic bags around the strainer, without removing it. If a pond stays near the drain for more than a day or two after rain, the drain is partly blocked or set too high.

The granules. The granules shield the bitumen from the sun. Where they are missing, you see smooth black patches. Exposed bitumen dries out, then cracks.

The seams. Each strip is followed, looking for a lifted edge, a corner curling up, a small mouth-shaped opening. A few open centimetres are enough for water to get in and travel between the two plies. Caught in time, this defect is simple to repair.

Upturns and flashing. At the base of the parapets and around the vents, we watch for these defects:

• a membrane that wrinkles or pulls away from the wall
• dried-out, cracked sealant against a pipe or a flashing
• a metal flashing that is bent, loose or missing a screw

Ask us for photos and a few lines of report after each visit. Compared from one year to the next, they show what is changing.

Frequently asked questions