Garage Roof Timber Sizes

This sizing guide for roof rafters will help determine what you need for your small project.

Garage roof timber sizes.

You need 170mm 400 centres otherwise 200mm joists. Common joists sizes are 200 x 50mm 175 x 50mm and 150 x 50mm. Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm. The joists will normally be placed at 400mm centres but no more than 600mm centres.

125mm x 16mm nominal size high quality scandinavian redwood tongue and groove boards. There are several variables to consider when determining the proper rafter size. The average one car garage size is 12 feet wide and 22 feet deep. Other common sizes are 14 x 22 16 x 24 and 14 x 24.

They re made to fit one car and can be used as a shed or even a small bedroom. You can use plain or treated but treated are obviously better for a roof which might get damp and suffer insect attack. You don t have wallplates for flat roofs. We use 100mm x 38mm framework which run top to bottom in the roof rather than the purling effect which has a higher likelihood of twisting then we support these with 100mm x 38mm trusses.

Metal roof sheets metal garage roof sheets are popular due to their ability to withstand extreme weather conditions affordability and ability to withstand high temperatures. 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 47 x 220 5 04 4 85 4 41 75 x 170 4 50. For pitched roofs flat roofs and ceiling joists. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.

Wherever possible joists should span the shortest distance. Usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below. Garage roof sheets are made from a variety of materials and each material comes with its own benefits so it is important to select the best one for your garage roof. That being said you have other options.

Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. 150mm joists wont span 4m.