On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases.
Flat roof construction uk.
As a mass rebuild of housing got underway it was discovered to be a cheaper alternative to the traditional pitched roof style.
What pitch is a flat roof.
Pitched roofs examples of pitched roofs.
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.
Flat roof construction for residential a roof is considered to be flat when it is of a slope of 1 5o to the horizontal.
While very common in countries with warm climates flat roofs were only widely adopted in the uk after the second world war.
A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less.
Flat roofs were uncommon in the uk until after the second world war.
A typical roof pitch in the uk for a traditional house will be 40 50 but at the extreme can go up to 70 above 70 would actually be called a wall.
When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.
The scottish technical handbook domestic describes flat roofs as roofs the slope of which does not exceed 10ยบ from the horizontal.
It must provide adequate protection against the elements keeping the buildings structure and interior dry.
Although flat roofs are cheaper to build than pitched roofs they have a shorter life span.
If your main interest is in flat roofs then you can learn more by reading flat roof construction part 4.
A flat roof usually consists of the following.
The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.
Flat roofing under construction plywood decking is then used to cover the joists with the width in between also determined by the weight being placed upon them.
Getting the balance right here is crucial as too much weight will inevitably lead to an unstable roofing structure.
As with many industries there s a whole world of confusing jargon built up around flat roof construction.
They were seen as a cheaper alternative to traditional pitched roofs.
A flat roof must be strong durable and stable throughout its lifetime.
Flat roof options help to free up internal space and are often cheaper that pitched roof options as they require fewer materials to cover the same roof span.
The reality is that flat roofs are relatively straightforward so we have written this simple guide to help you get to grips with flat roof lingo.
A pitched or sloping roof has a pitch of at least 15 but often much more.