Residential Flat Roof Construction Details
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.
Residential flat roof construction details. 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. This will give additional stability to the roof structure. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.
Most flat roofs are typically not as long lasting or durable as sloped ones because the latter shed snow and rain a lot quicker. A flat roof must be strong durable and stable throughout its lifetime. In high wind areas such as where a cyclone or hurricane may make landfall the main engineering consideration is to hold the roof down during severe storms. A roof is considered to be flat when it is of a slope of 1 5 o to the horizontal.
For additional stability you can also use steel joists that are built into one or both of the walls. Flat roofs on houses are primarily found in arid regions. Traditional homes often have sections of flat roof over shed dormers above porches and garages and on balconies. 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.
However over the last few decades new and advanced materials have been developed. But flat roofs take a pounding from harsh weather which is why they rarely last as long as a good sloped roof. A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. Flat roofs actually slope up to approximately ten degrees to shed water.
Flat roofs come in many shapes and sizes which include parapet roofs roof decks and green roofs to name just a few of the options available. Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. From there the flat roof system you choose will determine the materials you apply. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.
A classic flat roof is either almost completely level or has a very slight pitch of 3 in 12 inches or less. Ultimately a flat roof should play a part in a total architectural composition and has the ability to enhance the aesthetic and practical outcomes of a home. Flat roof construction for residential. A flat roof usually consists of the following.
Flat roof types.