Flat Garage Roof Timber Sizes

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Flat garage roof timber sizes.

Materials required to replace a typical single garage flat roof. Firrings 50 00 optional. Here we delve into the cost of the materials for a typical single garage flat roof. Im building my garage and have just been thinking about the flat roof timbers.

If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. 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. I was planning on using 4x2 c16 but i m not 100 sure if that will suffice.

New osb decking boards optional 50 00 each supply and fit inc vat. These span tables apply only to flat roof and roof with a slope of up to 10 degrees. Old asbestos roofs are often replaced with flat roofs. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

The span is 3000mm and they will be at 400mm centres. Flat roofs timber sizes and construction. There are several variables to consider when determining the proper rafter size. Flat roof with no permanent access and altitude not exceeding 100m 0 75 kn m udl 0 9 kn point load most areas exceeding 100m but not exceeding 200m excluding parts of scotland pennines north east england refer to bs 6399 3 1 kn m udl 0 9 kn point load.

As you may imagine there is a fair amount of weight involved here in terms of boards felt etc. Maximum clear span of flat roof joists in metres for sc3 timber spacing between joists size of roof joist 400mm 450mm 600mm 47 x 97 1 84 1 81 1 74 47 x 120 2 43 2 39 2 27 47 x 145 3 08 3 02 2 87 47 x 170 3 75 3 67 3 42 47 x 195 4 41 4 31 3 92. This sizing guide for roof rafters will help determine what you need for your small project. Sizes of joists needed for flat roof construction.

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.