The ceiling joists are used as the platform for the roof coverings.
Flat roof timber frame construction.
The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.
The roof is a key element of the building structure providing protection from the elements and has a vital role in reducing heat loss from the building.
It s been a couple of long days working solo to get it all up but it s rewarding stuff se.
Having a manual for warm flat roof construction with details and a summary of rules to follow helps.
For additional stability you can also use steel joists that are built into one or both of the walls.
Sizes of joists needed for flat roof construction.
Old asbestos roofs are often replaced with flat roofs.
Others would treat even steeper pitches as flat roofs.
As you may imagine there is a fair amount of weight involved here in terms of boards felt etc.
When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.
The flat roof shown above shows warm deck roof construction.
The fall of the roof is achieved by using firring pieces with a fall of 1 in 40.
The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof.
So any timber joists that are used need to be strong enough to support this weight.
In this type of construction the insulation is placed below the waterproof covering and on top of the roof deck and vapour barrier.