Roof sealer stops the drips

Choosing and applying roof sealant

Learn how to choose the right roof sealer for your home and how to properly apply it. Get professional results with our simple tips and level up your DIY game.

Types of roof repair sealant

There are several types of roof sealant available. Your choice will depend on the type of roof system, the type of damage, and where on the roof the leak has formed. In this article, we will deal mainly with shingled roofs.

Generally, roof sealer can be broken down into two categories: water-based and solvent-based. Water-based sealants are less expensive and easier to work with but usually not as resilient. Solvent-based products are thicker and can be more challenging to work with, but the repairs last longer.

The two factors to keep in mind when choosing roof leak sealer are water exposure and sun exposure. Both will test the quality of the roof repair sealant.

Silicone roof sealants are quite popular for roof issues because they protect well against moisture and UV rays. Roof silicone sealant tends to be more expensive but gets the job done.

Liquid rubber sealants are also quite effective as they provide a powerful barrier against sun and rain. These sealants are often found in thin, water-based formulas. They are easy to use and great for small cracks and tears in the shingles.

For shingled roofs, the most common roof sealant is asphalt-based sealant. This type of sealant forms a durable, water-tight seal and stands up well to the intense Australian sun and environmental extremes.

How to use roof sealants

The first step in using roof leak sealants is, of course, to locate where the water is getting in. This can be more difficult than it sounds. Sometimes water enters through a small crack and travels down the roof sheathing or rafter and actually drips further down. This can give a false impression as to where the leak is when observed from inside the house.

Be sure to inspect the underside of the roof from the roof cavity if possible. In really difficult cases, it may be necessary to run water from a garden hose onto the suspected area while someone else watches for the leak from inside the roof cavity.

Once the leak has been found, the battle is half won. Now you will inspect the damage and determine the best roof sealant to use.

Common problems are torn or missing shingles, tears around a roofing nail or a nail placed where it is exposed to the weather (rather than under a shingle), and loose or damaged flashing.

If the problem is an exposed nail, simply apply a generous dab of black roofing sealant and make sure the edges of the tar are smoothed into the surrounding material so that water can’t get underneath.

Torn sections of shingles can be re-glued with asphalt roofing sealant as well. Gently lift the torn section, apply a generous amount of sealant underneath, and reposition the shingle. Press down firmly to ensure good adhesion.

Another common place for leaks is around window and dormer flashing. These are the metal strips folded at a 90-degree angle that fill corners where the side of a dormer meets the roof. Sometimes part of the metal is visible, so a clear silicone sealer will be much more attractive than black asphalt roof sealant where water may back up or puddle during a rainstorm.

Clean up excess asphalt roof sealant with paint thinner and a cloth. If the sealant has dried, try a citrus-based cleaner and allow it to sit on the dried material for several minutes to soften it up. Then wipe it away with a cloth and paint thinner.

Choosing the best roof sealer for your job

So now you have a good idea of how to repair minor cracks and tears in your roofing materials. Choosing the right roof sealer will depend on your situation. Consider the type and colour of the shingles, flashing, or other materials. Always read the labels and specifications of any roof repair sealer and follow directions closely.

As you are inspecting your roof, you may find a small area or two where a bit of plywood has chipped or broken away or perhaps you’ll notice a larger gap that can easily be filled with sealant that once mixed, hardens into a durable gap-filling adhesive. It can be sealed over, painted, and even drilled into to set an anchor or screw.

Loctite Epoxy Quick Set is an excellent choice. It forms a high-strength bond in just 5 to 10 minutes, is resistant to water and most solvents, and comes in a convenient double-syringe applicator.