Don't panic if your roof is leaking! The best way to prevent and repair roof leaks! Roof leaks are a major problem, but don't worry!
Water-facing repair method
This method is like putting a "waterproof coat" on the roof. It's applied directly to the leaking surface, effectively blocking rainwater intrusion and is very thorough.
Back-to-water repair method
Grouting the leaking area will make the concrete denser. While it may appear fine in the short term, it only treats the symptoms, not the root cause, as water on the roof will still migrate elsewhere.
Repairing roof leaks in commercial buildings
Compared to self-built homes, repairing leaks in commercial buildings is relatively simple. There are two main types of leaks in bathrooms, balconies, and kitchens: severe leaks around pipes and irregular leaks throughout the entire roof.
Leaks around pipes
Symptomatic treatment: Use a slow-setting sealant with a polyurethane waterproof coating. First, clean the area around the pipe. Apply the sealant until it's semi-dry and not too thin. After half an hour, check to see if it's hardened. If it is, you can apply 911. Alternatively, you can use a leak repair tool. However, these methods are only temporary solutions; leaks will still occur in other areas where the waterproofing layer is incomplete.
Cure the problem: Re-waterproof the upper floor and use an electric hammer to break open the pipes and re-seale the leaks. For bathrooms, re-waterproof the entire building, otherwise leaks will reappear in other areas.
Irregular leaks and cracks on the roof
This is usually caused by inadequate waterproofing on the upper floor and is most common in commercial buildings with prefabricated roofs. The temporary solution is the same as above: clean the leaking area and then seal it. Another common method now is to "inject" the roof.
Repairing Leaks in Self-Built Roofs
For leaks in self-built roofs, first determine whether they are global or localized, as the treatment methods vary greatly. For isolated localized leaks, you can use cement, asphalt, or other methods to seal the leaking area from the roof, which is generally a solution.
Five Methods for Roof Leak Repair
- Seamless Sealing: Roof leaks are mostly caused by cracks and gaps. If the gap is less than 1mm, do not use sealant; simply apply two coats of water-based waterproofing paint, with a width of at least 20cm. This ensures strong adhesion, allowing the waterproof coating to penetrate and bond, providing excellent elasticity and a long service life. Be careful not to expose the roof to rain for 12 hours. If the roofing material is unusual, other waterproofing materials can be used. Waterproof the tile surface with a waterproofing agent, and sealant can be used to waterproof the gaps.
- Remediating hollowing and leaks: If the floor is hollow, first use a cutter to remove the plastered surface within the hollow area. Then, apply two coats of polyurethane, extending 10 cm on each side of the crack. Then, apply cement mortar before applying the top coat. For large-scale leaks, it is recommended to apply two coats of acrylic waterproofing paint, as the black color of polyurethane absorbs heat and affects indoor temperatures in summer.
- For existing waterproofing: Remove the surrounding waterproofing and reapply new waterproofing, ensuring a reinforcement layer is applied at the junction with the existing waterproofing.
- For existing waterproofing: If the roof is only partially waterproofed, simply remove the leaking area 2-3 cm deep and clean it thoroughly. Apply a layer of waterproofing, topped with a protective layer of cement mortar.
- For leaking sloping roofs: Clean grass, moss, and rotten leaves from the tiles. Tiles that are cracked or perforated should be replaced.
