April is the month when spring showers will test your home’s ability to shed water. Roofs, gutters and basements are especially susceptible to water leakage that can damage your home. Check these three crucial areas for seepage.
• Look at ceilings for brown rings that radiate outward from a central point. The drywall or plaster will be soft within the circular area and may even crumble when touched. In severe cases, water will be dripping on to the floor below.
• Climb on to the roof and examine the shingles or other water repellant covering. Look closely at valleys or low spots on the roof where water can collect. If the roof covering is in reasonably good condition, small declivities can be sealed with good-quality plastic roofing cement; leaks at valleys can be sealed by lifting the valley shingles and applying the cement to the flashing beneath.
• Examine flashings around chimneys and other pipes that protrude through the roof. During the spring freeze/thaw cycle, melt water can seep under flashings during the warm daytime, then freeze and expand at night, causing nails and adhesive to lift. Refasten metal or polymer flashing that has lifted by pulling the old roofing nails, scraping off old adhesive and applying a light coat of plastic cement under the flashing. Nail the flashing back in place with new, longer roofing nails and cover the heads with cement.
• Shingles with corners that are rounded upwards should be replaced with new ones. Older metal roofs held in place with visible screws fitted with neoprene washers may require the replacement of some or all of the washers, which start to leak when broken down by components of sunlight.
• Check the gutter and rake edges of the roof for back seepage. Most modern roofs are sealed at all edges with a three-foot-wide band of waterproof polymer sheet that adheres tightly to the substrate. Lengths of galvanized metal are also placed between the shingles and the polymer sheet to divert water into the gutters and away from the house at the rake edges.
Older roofs do not have drip edges and/or have a starter strip of shingles in place of an adhesive polymer sheet, so are prone to back seepage at the edges. OSB substrate will begin to break down after a few years of exposure to snow melt and rain, allowing water to seep under shingles and damage structural members as well as exterior and interior siding of your house.
If substrate rot is limited to about 12-inches from the roof’s edge, shingles can be peeled back far enough to allow rotten OSB (sometimes plywood or boards on older buildings) to be removed and replaced with new material. It’s good practice to remove the starter strip and replace it with a polymer sheet before nailing the shingles back into position. Install drip edge between the shingles and polymer sheet for good measure.
• Plugged gutters, or eavestroughs, prevent rain or melt water from draining off your roof and away from your home’s foundation. The results can include everything from rotting fascia boards, siding and window sills to seepage through basement walls, leading to fungal growth in a newly-finished recreation room.
• If your house is surrounded by trees, then dead leaves must be removed from the gutters every fall to prevent the build up of leaf dams that impede or block the flow of water through the troughs and down the side pipes. Use a ladder or climb on to your roof to inspect your gutters. (An inexpensive device called a “ladder stand off” attached to your extension ladder will prevent it from leaning against eavestroughs and denting or crushing them.)
• If the leaves are weight heavy, the most efficient way to remove them is with a long, high-pressure nozzle (available at lumber stores) attached to an outdoor hose. Dry leaves can be blown out of the troughs with a good quality leaf blower.
Down pipes may require a blast of water to clear them. Check for flow by filling your troughs with water, which should gush freely out of the end of each downpipe.
• Gutters and their components can be sealed with a variety of caulking materials, including butyl rubber, polymer and urethane. Silicone-based caulk is not recommended, because it cannot be painted or resealed without removing the old caulk.
• Check your basement walls for water leakage. Unfinished concrete walls are naturally the easiest to examine. Wet areas below windows or damp areas along the base of the concrete are suggestions that rain and melt water are not being properly diverted away from your foundation. In finished basements, mouldy or musty smells are warnings that moisture is getting in to your basement.
• If your gutter system is operating correctly, check your window wells to ensure they are properly installed and sealed. Modern houses should have a pipe filled with stone cut off at ground level at each window well. The pipes are connected to weeping tile that surrounds the bottom outside wall of your basement.
If the window well pipes are clogged, water builds up inside the well, seeping into the soil and, as moisture takes the path of least resistance, through the hygroscopic (water-absorbing) concrete walls of your basement. Replacing window well down pipes is a job best undertaken by a contractor.
• Damp or wet areas at the base of interior basement walls are often caused by weeping tile that is defective or has become clogged by tree and plant roots.
• Weeping tile used for new homes consists of lengths of polymer pipe with small holes to collect excess ground moisture and channel it away from your home’s basement. Weeping tile in older homes is made of clay which gradually breaks down in service. If you suspect your weeping tile is no longer working correctly, the best, though costliest, solution is to have a qualified contractor examine your basement.