But now flat roofs often are constructed with fewer layers because of improved waterproofing technology.
Flat roof felt systems.
Layers of bitumen felt are heat welded onto each other to form an impenetrable barrier.
Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules.
Roofing felt is one of the oldest available options and advances made in the past decade or so have begun to move more towards the torch on approach.
While laying felt is not an easy job it can be done by anyone who has the patience to deal with it.
Roofing felt is one of the more popular and traditional methods of creating a flat roof.
Felt roofing also known as tar paper is traditionally installed using hot bitumen to create a secure bond between the roof and the felt.
Step 1 prep work.
Flat roofs are hard to replace.
This could mean flat roofs may not raise the same red flags they used to.
However it wasn t particularly long lasting or durable so torch on felt was created.
Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed.
Here are simple steps to get you started.
The underlying deck must be constructed of moisture tolerant materials such as 18mm wbp plywood or suitable chipboard stirling board on treated timber joists.
Here is a video showing how the felt is installed on the flat roof.
The hot applied asphalt or coal tar pitch blends with the bitumen soaked roof felt and creates a monolithic roof membrane.
Some observers suggest it s harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers especially on older flat roofs.
This type of flat roofing felt has been in use for decades and is still used today.
A bottom layer or two of insulation board multiple intermediate layers of tar or asphalt alternated with layers of roofing felt and a top layer of gravel.
There are many different types of flat roofing systems available each one with their own pros and cons.
Built up roofs are installed using several layers of a special type of roofing felt that has been asphalt impregnated and embedded in bitumen applied with a hot mop.
Check to ensure the roof is in good enough condition to walk over.
Make sure the roof is clean dry and that all nail heads are flush with the deck.
Bur consists of many layers.
Light weight shed roofing felt is not suitable for flat roof construction.
Pros and cons for flat roof materials all three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof.
Felt is laid on a flat roof to help keep the roofing system waterproof.