Garage Roof Joist Centres

Los angeles residential code 8 roof ceiling construction r802 wood roof framing r802 4 allowable ceiling joist spans jump to full code chapter spans for ceiling joists shall be in accordance with tables r802 4 1 and r802 4 2.

Garage roof joist centres. Permissible clear span metres. Builders aren t bound by standard rafter spacing measurements. Although you can construct a garage using thicker stronger joists 2 inch by 6 inch joists are sufficient for most garages even if you intend to build an attic storage area above your garage. Not more than 0 5 more than 0 5 but not more than 0 75 more than 0 75 but not more than 1.

But they do tend to space rafters in one of several industry standard increments typically. Rafter and roof joist spacing is only one part of a complex roof design that works together to form a structure that meets building codes and can hold up the weight of the roof and roof load. One of the joists in my garage is getting beyond saving and starting to sag so it needs replacing. So i would be able to put a post in between garage door to rear exterior rear wall we don t want any support in middle city van nuys ca job is.

The garage is an existing garage with a flat roof with small slope for drainage. Its a pair of 3x2s on a 2 7m span so maybe a little under sized too. Surveyors span tables for designing roof rafters. 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.

Dead load per square metre in kn m supported by joists. The problem is the slot for the timber is only deep enough for the current sized joist. Front of garage has to 8 ft. If the garage has a simple peaked roof dropping 2x6s free of large knots from the peak and tying them into the center of the ceiling joists would cut the span in half.

Half the span means 4 times the load carrying capacity from a strength standpoint the deflection would be 1 16 that of the full span. Fine homebuilding notes that 2 inch by 6 inch garage joists will support a weight of up to 50 pounds per square foot. Centre to centre spacing of joists in mm joist size width depth mm 400 450 600 400 450 600 400 450 600.