One of the most important features of your home and outbuildings is the roof, as it offers protection from the elements and helps guide rainwater into the guttering and away from the walls & foundations. A standard pitched roof should last approximately 100 years before it needs to be replaced, but the life expectancy of flat roofs tend to be much shorter and often need replacing after 10 – 15 years. However, flat roofs cost much less to install, are relatively cheap to repair, making them a popular choice for outbuildings such as a garage or extension. Here are a few tips on maintaining your flat roof and when to repair or replace.
Temporary Flat Roof Repairs
A temporary roof repair provides a quick and cost-effective solution for the short term, and should be relatively easy for a competent DIY’er. Most splits, cracks and lifting joints on felt roofs can be easily rectified using a paint on waterproofer or bitumen type sealant that you can purchase from your local home depot store. If you’re dealing with a relatively large split, it may be worth applying a small patch over the sealant for added strength. Do not use too much waterproofer as this could make any future repairs more difficult and expensive to fix.
Another common problem with flat roofs is leaking flashings, where the roof joins the wall of the house. This can cause significant internal damp problems as water blown against the wall will run behind it and into your property. The best solution is to carefully remove the old mortar and repoint it with a new mix. However, this requires slightly more expertise, and you may be better off contacting a specialist roof builder.
Permanent Flat Roof Repairs
A successful permanent repair should last for the remaining life of the roof covering until it’s in such bad condition that a new roof is required. Most felt roofs can be repaired by adding a new layer of felt, or by applying patch repairs using a blowtorch or blowlamp to fix them in place. You can then apply a layer of paint on waterproofer or bitumen type sealant for extra protection. Asphalt & Concrete roofs can also be given a new lease of life by fitting a layer of felt on top of the existing roof covering, and then fitting new edge details and metal flashings. Make sure the roof surface is clean of grit and dirt before applying a new layer of felt.
Before re-covering a flat roof, it’s worth inspecting the overall condition and structure to avoid covering up problems rather than fixing them! Fill in any cracks with asphalt or concrete and remove blisters (Asphalt only) with a power sander or a diamond floor grinder for larger areas – You can rent a floor grinder from most tool hire centres. It may be worth applying a layer of solar reflective paint to protect the new felt.
Alternatively, you could opt for a professional liquid based roofing system, but this will probably be more expensive than the cost of replacing your roof. This is a great solution for large roofs or commercial buildings due to economies of scale, but we would advise against it for residential properties. If you’re unsure how best to fix your roof, it may be worth contacting a professional roof builder to carry out an inspection and offer specialist advice.
Replacing Your Flat Roof
If your roof is in a bad state of disrepair, or you notice signs of structural damage or internal damp, it may prove more cost effective to replace your roof. Start by inspecting your roof for ridges or dips, as these suggest structural damage to the wooden joists, or the roof decking boards, caused by leaks or internal condensation. If there are sufficient hollows or ‘sagging’ between the roof joists, your best option is to replace the roof.
If you cannot see any visible signs of structural damage, it may be worth performing the ‘walk test’. Start by standing on a roof joist and carefully press one foot onto any suspect areas to check the firmness. If there are no visible signs of damage, walking on the roof should give you an idea of its structural rigidity. If it feels firm underfoot, you may be able to apply a permanent repair rather than replacing your roof, but we recommend contacting a professional roof builder if you find any weak spots.
Here are a few tips for maintaining your roof:
- Fact: A flat roof should NOT be 100% flat! All flat roof designs should incorporate a gradual decline of 6% to 10% to guide rainwater away from the roof and into the gutters. Remember, the better the drainage, the longer your roof will last.
- Remove any build-ups of grit and debris, as these can promote the growth of moss & algae which can damage the roof covering.
- Felt roofs should be covered with chippings or solar reflective paint to avoid damage from prolonged exposure to the sun.
- Inspect your roof regularly as many issues can often be dealt with quickly at minimal cost.
Maintaining your flat roof and applying temporary repairs may seem fairly easy for a competent DIY’er, but the difficulty is often accessing it safely. If you have difficulty accessing your roof, or require permanent repairs or a new roof, why not contact CPM (Complete Project Management) today? We specialise in roof building, repairs and maintenance for residential and commercial properties in Exeter, Mid & East Devon and parts of Somerset. Call 01392 925045 or contact us online for a free no-obligation quote.