How To Install Joists For A Flat Roof

There are key differences between constructing a flat roof compared to a pitched roof and it s important to understand the basic criteria.

How to install joists for a flat roof.

So any timber joists that are used need to be strong enough to support this weight. A cavity closer should be provided to the top of the walls to prevent fire spread and to stop damp air entering the roof space. As you may imagine there is a fair amount of weight involved here in terms of boards felt etc. To build a roof joist for a flat roof you need some carpentry skills and a few basic tools.

Measure and mark the joists at each end of the roof about 4 feet in from the edge. Old asbestos roofs are often replaced with flat roofs. Step 1 measure top wall plate. In the warm flat roof construction there is insulation packed into every possible space where air can flow.

The roofing surface is installed over the joists while insulation is placed between them and the ceiling beneath is suspended from them. Drive screws into each pilot hole to fasten the joists in place. The starting point involves laying roofing joists across the two upright items which in most cases will be the walls of the structure. The roof joists will need to be spaced at 16 inches on center.

In order to get the right amount of 2 by 6 lumber to use as your roof joists you will need to measure the top wall plate. Where a new flat roof abuts an existing external wall the joists can be hung on metal joist hangers which are fixed to a horizontal timber plate wall bolted to the wall. This means that from the center of one joist to the center of another there is 16 inches. Here s a how to guide on joist hanger installation.

Sizes of joists needed for flat roof construction. The major difference between the warm flat roof and the cold flat roof has to do with the air flow between the roofing timbers known as joists that help to hold up the roof. Corbett grace their parents and even their kids are learning a lot about the many ways a few right many wrong to build a high performance home.