Method 1: Flat Roof Repair
Diagnosing a Flat Roof Damage
You should first measure how far the roof leak is from the two closest walls. You do this by identifying your wet or stained ceiling. Sometimes it’s a smell of dampness during the rainy season. Then measure the distance from the stain to the nearest walls using a tape measure. Climb up your roof and use the same measurements to identify the damaged part of the roof. The damage is most likely within the measurements you got or anywhere close.
But keep in mind that it’s possible that the damaged part of the roof is far from within your measurements. The reason is that not all flat roofs are perfectly flat. This feature is allowed to let water to flow. Like in the case of our client above, damage can happen at the highest point of the roof then lets in water to flow to the lowest part of your home (where you see the problem).
Examine the Slope
When you get on top of the roof surface and identify the position of the damage, examine the slope. The problem might be a crack, a tear, a puncture, or a missing part of the roof. Find out how it’s possible for the leak to penetrate the roof structure to reach the ceilings below. If your roof has been around for many years, you might realize there are multiple damaged spots. In this case, classify the issues so that you have problems you can tend to immediately and those that can wait. Whatever is letting in water is an emergency – whether big or small.
If the Roof Looks Fine…
Check the seams. The sides of your roof may be the source of the leak. So go around the edge of the roof to identify any weaknesses. You might notice leak problems where the walls attach with the roof, around the vents, or chimneys. There could also be a problem with the water repellents, metal flashing strips.
Clean the Damage
Now that you know what the problem is, it’s time to prepare the place for repairs. A dirty surface makes it hard to get quality results when you decide to repair the damage – the repair material might not bond properly. Also, cleaning the area provides the opportunity to see the problem better. So clean the damaged area by removing the debris, dirt, gravel, and stagnant water. A tough-bristled broom and a mop will come in handy for this purpose.
After cleaning, dry the target area using a piece of cloth or towel. While you can use mechanical ways to dry your roof, it’s better to let it dry on its own for a day or two. Then use a sealant, roofing caulk, or cement to cover it. Ensure you press your repair material so it reaches every corner of the damage, then level it so it’s even with the rest of the roofing surface.
Method 2: How to Seal Small Cracks and Holes
If you realize your roof has blisters, that’s as a result of trapped moisture and overheating. Pop these swollen or blistered parts on your flat roof using a utility knife. Ensure the cut is shallow so you don’t puncture the roof material. Then scrape off any protruding roofing material and throw it away. If it feels wet, wipe the area using a rag until it’s dry before applying a sealant.
In some instances, forcing a sealant on these areas can be difficult requiring you to create a shallow “pothole” for the sealant to stick. So take your knife and curve a shallow cut as you remove the material around the area. Alternatively, cut narrow strips on the damaged spot so it’s capable of holding and bonding with the sealing material. Again, be careful not to slice through the roof material.
Apply a Coat of Roofing Cement
Fill the section you’ve cut out on the roof with a layer of roofing cement. Push the cement into the carve then level it so that it evens the rest of the roof. Cover about 15 cm wider than the damaged area. If the holes or damage is 2.5 cm or less, seal it using caulk. Afterward, take a piece of fiberglass mesh and cover the patch to waterproof it. Make sure the mesh is holding down onto the cement by tapping and pressing it in place.
Open up your can of roofing cement again and cover the fiberglass mesh. This should be thick enough to hide the mesh underneath it. Then use a trowel to smoothen the surface. Don’t leave your repair as it is because UV rays might destroy it by breaking the chemical bonds holding everything in place. Take ballast and spread it over the cement patch then use your trowel to spread it over evenly and to cover all the cement patch. This absorbs UV rays to allow the repair to last longer.
Another important ingredient you shouldn’t forget is applying a layer of a reflective coating. As the name suggests, it will help reflect the sun rays that can break down the chemical bonds in the cement.
Method 3: Using a Roof Repair Kit
You can buy a roof repair kit that contains everything necessary to patch your roof damages. Most kits contain patches that help solve leaking problems from larger surfaces and caulk for sealing cracks and small holes. With a kit, you have everything you need to successfully repair your roof. Make sure you compare the color of the patches with that of your roof color.
Use your utility knife to cut out the damaged area, removing any loose particles, dirt, and grime. You can cut into the roofing membrane as deep as two and a half centimeters. If the damaged roofing material isn’t removed, you can still go deeper but make sure you don’t puncture the lower layers of your roof.
Fill the Damage on the Flat Roof With a Layer of Roofing Cement
Shop a can of roofing cement (make sure it’s labeled for the type of roofing you have to effectively repair the damage). Then spread the appropriate amount of the cement on the damaged area so it doesn’t overflow or is too little. Use a trowel to press it in the damage as well as make a smooth surface, even to the rest of the roof. You want to apply cement around the damage for about 5 centimeters from the damaged section.
Cut a patch that is slightly wider than the area you are repairing. Then take and place it on your freshly spread roofing cement. Press the patch to make sure it sticks. If necessary, cut the patch so it’s the right size to the area covered with cement. After the patch, cover your repair work with a layer of roofing cement. Make sure this coat covers past the patch. Then smoothen it so it’s at the same level as the rest of the floor surface.
To ensure the surface is not exposed to water damage, add another patch to the area you are working on. This time, the patch should also be slightly longer and wider than what you’ve already laid on the floor. You might realize the repair work more protruding this time considering that the last repair layers were leveling the rest of the roof. While it might affect the aesthetics of your roof, it’s a move that makes your work more long-lasting. The good part is that most flat roofs are not visible to the public. The protruding part won’t be a big problem.
Just like before, press this patch on the roofing cement surface so it sticks. Try and make it level your roof surfaces as much as you can. The edges must bond with your roof material to prevent water damage and moisture from penetrating the patch. So get your roofing cement, add it around the edges (while they are dry) then press the edges of the patch to attach it to the roof.
It’s now time to add the final layer of roofing cement. Scoop it and add a thin coat to the patch. Try as much as possible to make the layer even to the roof materials. Then protect the surface from UV rays that can potentially break the chemical bonds in your patch by adding ballast to the repair mark. Alternatively, find a reflective coating material and apply it to your patch to protect against sun damage.
Method 4: Resealing Your Entire Roof
Clean the Roof
Resealing your roof is the option you go with if there is too much damage to your roof. You begin the process of cleaning the roof surface. Use a hard-bristled broom and clean away debris, dust, and clear all the damaged surfaces. Dispose off the dirt according to your local government requirements. Roofing contractors already understand this that’s why you should involve a roofing company from the onset of your repair project.
Apply a Bitumen Primer
Get ready with a paint roller, then pour a generous amount of bitumen primer on the roof surface – from one of the corners. Use your paint roller to spread the primer on the surface. Ensure your spread is even, about 1 cm thick. Coat the roof surface neatly from one end to the other. Add another pour of the bitumen primer when the initial one depletes until you cover the whole roof.
After you’ve successfully spread a coat of bitumen primer on the roof surface, give it time to dry. Not less than 20 minutes. The drying time might take longer during cold seasons. Also, read the manufacturer’s drying recommendations to be sure your bitumen primer coat dries properly. Try the primer after the dry time is over by using your finger to be sure it’s properly dry. If you use a bitumen primer that’s not set, expect the sealant not to bond with it properly, which will result in poor quality work.
Layer Your Dry Primer With a Sealant
Mix your sealant to create a smooth semi-liquid substance. Use a mixing stick to stir through the can so that its components mix properly – the solid part will rise from the bottom to mix with the liquid part. It should be easy to pour and spread across the roof surface.
Then just like you did in the first step, begin by pouring it in one corner of the roof then use a paintbrush to spread it evenly as you move to the other end of the roof. It’s important to work in one direction so your work is smooth and about 1 inch thick all around.
Lay a Fiberglass Mesh Over the Wet Sealant
You can get fiberglass mesh in big rolls. So measure your roof and buy one that fits well. But be careful the size you buy because carrying the mesh up the roof can be an uphill task, literary. If you already bought a big mesh that is making it hard to take to the roof, ask for help from a friend or cut it into manageable bits. When you get it up there, use a pair of scissors to cut its edges so that it fits on the roof accordingly. Clamp one end of the fiberglass mesh to allow you to spread it effortlessly.
Unroll the mesh over the wet sealant if it’s in a roll or unfold it if it’s folded. Use any weights you can find around you to secure the mesh flat on the roof as you cover your surfaces with it. By the end of it, let the mesh be at the same level as the roof surface without bumps or uneven spots.
Cover the Mesh With Another Sealant Coat
Once your fiberglass mesh is in position, take your sealant and brush it over the mesh. This should be another half an inch of sealant coat. Doing this not only holds the mesh in position but also completely seals out moisture in the future. You can let the mesh overlap your roof surfaces for about 2 inches.
Depending on the size of your home, do this process severally until you cover the entire roof. Finally, let your work dry for the next 12 hours. If possible, let it stay for a few days before you can apply another coat of sealant. If you think the roof is dry enough, it’s time to spread your sealant. Then give it time to dry and check your work afterward.
You will notice dark patches and small holes which indicate that the specific sections are not waterproof. So, seal these isolated marks as well as fill the holes. Then spread another layer of sealer all over the roof, half an inch thick.
Add a Reflective Coating
A reflective coating ensures that your work is protected from the sun’s rays. If you leave your roof exposed, UV rays hit it to break down the chemical bonds. So open a can of reflective coating and stir it using a stick to make an even paste. Get a paintbrush to help you reach the hard-to-reach areas of the roof with the reflective coating. Then take a paint roller to quickly spread a layer of reflective coating on the rest of the roof. Ensure your work is even and smooth all around the roof.
You could choose to use rocks or ballast which absorb the UV rays instead of reflecting them away. Your reflective coating might take more than eight hours to dry depending on the weather conditions.