Flat Roof Repair Solutions: How to Fix a Leaking Roof


Flat roofs are common for both commercial and residential buildings, as they usually cover a large area and are relatively easy to install.
However, flat roofs are known to leak more often because water does not roll off due to the absence of slope, and just pools until it evaporates.

Small water droplets or leaks don’t seem to harm anyone, but prolonged exposure to water and snow can cause the roof to become moldy and rot. This can considerably weaken the framing and cause the roof to collapse, posing a serious threat to your personal safety and the structural integrity of your house. Therefore, you must detect the area of the leaking and fix it quickly to avoid further damage to your property.

How to Spot a Leak on a Flat Roof

If you suspect that your roof is leaking, start looking for any external penetrations, holes, or other visible damage to the roof, as these are the most common causes of leaks. Penetrations that can cause leaks usually occur around plumbing vent pipes, bay windows, chimneys, and any other structures protruding from the roof. However, leaks can take place several feet from the abovenamed constructions, so make sure you thoroughly examine the entire roof.

Here are the steps that will help you to find a leak on flat roofing surfaces:

  • Remove leaves, shavings, or other debris from the roof. Pay attention to any damage to the roofing material, like holes or other irregularities that may be the main cause of leakage.
  • Check if any roof nails are missing or whether there is rust on existing ones, as these may cause leakage. At the same time, examine the guttering around the flat roof for obstructions.
  • Collars and flashings must be inspected because of the protection they give a roof. If they are twisted or missing, the leak might be around the edges or penetrations.
  • Examine the metal flashing as you walk around the roof. Typically, two layers of flashing are used. The inner layer, also known as step flashing, protects the area where the roof’s timber sheathing meets the chimney, dormers, or other openings in the roof. The counter layer is a distinct outer layer of flashing that acts as an independent protection layer for the step flashing. These two layers of flashing must be able to expand and contract in response to changes in the roof’s temperature. If this does not occur, the flashing may enable water to penetrate through the roof covering.
  • Identify low spots. A flat roof is not entirely flat, the surface is sloped in some areas. If a leak is detected, a roof inspection could identify a low point where water pools, thus degrading the roofing material and causing a leak.
  • If the source of a leak cannot be located on the roof but there are water spots on your ceiling, measure the distance from this area to the nearest wall. Go back to the roof to refine your search area using these measurements.

Now that you have identified all the places where the roof is leaking, it’s time to patch them up.

London Building Contractors provides an inexpensive and quick solution to roof leaks with our tried and tested flat roof leak repair kits delivered straight to your door.

Many flat roofs are affected by ponding water due to inadequate drainage. Our solutions are ideal for flat roof ponding repair and patching any cracks and holes that may lead to a serious leakage. However, you need to thoroughly assess your roof covering type and its current condition prior to selecting the repair method.

We don’t think that there is an all-round approach to leakage problems, which is why we have a selection of high-performance flat roof repair materials featuring various application properties to meet your current needs. Our most commonly used materials include the following: PVC membrane, EPDM membrane, Asphalt, Bitumen, Felt, Concrete, Fibreglass, or Metal.

Bitumen & Asphalt Flat Roof Repair

Common problems with bitumen roofs include bubbling from heat, cracking, creases, or slitting and shrinkage.
When it comes to the restoration of damaged bituminous membranes, numerous methods can be applied. For instance, the slopes of bituminous substrates can be renovated with a single-component bitumen and water-based levelling paste.

The use of high-quality bitumen and polymer adhesives is recommended for sealing overlapping joints in the cold-laying practice of polymer modified bitumen sheet membranes.

Concrete Flat Roof Repair

Cracks and surface wear are the most common damage problems to concrete roofing. Surface wear can conceal cracks so make sure to clean any loose debris from the rooftop.

Large and more ‘noticeable’ cracks on a flat roof can be fitted with a tiny piece of roofing felt.

EPDM – Rubber Roof Repair

Incorrect installation, shrinking and seams are the most common problems for rubber roofing. The rubber roofs are renowned for their durability but they also require proper maintenance.

EPDM is an extremely durable synthetic self-adhesive rubber roofing membrane widely used in low-slope buildings.

For leaks and cracks, a little patch might serve as a permanent EPDM roof repair. The patch should be attached with a firm, hard roller from the center (over the hole) outwards.

Felt Flat Roof Repair

Felt roofing can crack, get puncture holes, or the felt could split. Edging can also lift, or old flashings against the wall could leak. The surface may also suffer from dips or hollows.

We have a wide range of liquid rubber coating kits to protect your flat roof by making it waterproof and damage-resistant.

Fiberglass Flat Roof Repair

GRP flashes close to outside walls, fissures near board joints, trims, and upstands can be the main sources of damage to fiberglass flat roofs. Cracks might also form because of expansion and contraction due to seasonal temperature fluctuations.

The best solution is cutting out the damaged spot and replacing it with a new thermoset plastic composite and a top coating, ensuring that everything is correctly installed to avoid the same problem occurring.

Metal Flat Roof Repair

Corrosion sealant is the perfect solution for sealing joints on literally all types of metal roofs or facades. It provides a water-resistant, moisture-proof, and airtight barrier, without any additional sealing.

At London Building Contractors, we offer reliable sealing solutions that ensure excellent adhesion to every type of metal.

Not sure which method to choose? Experts at London Building Contractors can inspect your roof and help you decide on the best repair method for your property.

All our customers have the choice to purchase materials directly from us or we may assist them in buying these at the best price!

For more information, contact us on 020 8935 5159.

Posted on: July 15th, 2021 by London Building Contractors No Comments