Whether you have a flat roof on a garage, extension or shed, or own a three storey house, you need a layer of felt to give the top of your structure extra protection against the elements.
Flat roofs and sheds are more than covered with just roofing felt, but obviously if you own a house or commercial property with a pitched roof, then you will need something more than just felt. Hence such buildings have shingle roofs too.
The main element roofing felt helps protect against is moisture, especially rain, because water can easily find its way into your rafters if all you have is shingle tiles as the top layer of your property. This is where you need to know how important the choice of roofing elements are.
Applying roofing felt also gives extra protection to your roof overall when it comes to roof edges. If you are doing it yourself or have hired a roofer to do it for you, you will want to make sure the felt overlaps the areas where rain could get in. For instance on a garage flat roof you will want the felt to run up any vertical walling rather than just finish flush to the wall.
Naturally, you will find there are different types of felt for flat roofs as there are for pitched roofs and sheds. You can find that online or at your nearest hardware shops as well.
There are also different “weather” conditions that may exist within the roof space once all work has been completed and the building starts to be lived in. Humidity and condensation are two examples, and so you may need to be careful you use the right roofing felt or membrane to account for this. Roofing materials are weather-sensitive and if you settle using the not so practical stuff, you’ll end up spending more in the next coming years.
Some notable roofing felt products you will need to consider are Air Permeable Membranes, Vapour Permeable Membranes/Felt, Non-Permeable Membranes/Felt, Shed Felt, Timber Frame Wall Breather Underlay and Metal Roof Underlay, as well as SBS and APP Torch-On Felt.
For example, if you have an inner roof space where there is a risk of high condensation then you will want to make sure an Air Permeable Membrane is used. I’m sure everyone desires the same thing too.