Standard Flat Roof Joist Sizes

Cb100 12 cb150 16 cb200 20 product description.

Standard flat roof joist sizes.

A 2 by 4 inch joist for instance hangs into the room by 4 inches which may leave the ceiling high while a 2 by 12 inch joist in the same position hangs 12 inches into the room which decreases the ceiling height by 8 inches. The difference in the joist sizes applies to the width of the boards which determines the height of the ceiling. The range of joist sizes used in homes varies though between 2 by 4 inches and 2 by 12 inches. This is the distance between joist centres.

L 480 live load deflection. Size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x 220 1 77 2 40 2 89 3 38 3 87 4 36 2 04 2 75 3 47 4 20 4 93 5 66 floor joists flat roof joists assumptions at 400mm centers supporting permanent load excluding self weight of joists up to 50kg m2. Not all products are available in all markets. 56032 8 29 8 28 0 25 2 1 32 8 29 8 26 3 1 20 11.

28 foot 11 30 foot 12 32 foot 7 34 foot 1 36 foot 6 40 foot 5 50 foot 3 60 foot 3 when making a selection below to narrow your results down each selection made will reload the page to display the desired results. Rafter and joist span faq. Contact your ilevel representative for information. The lengths and sizes of joists vary depending on the species and quality of the lumber used.

These span tables are designed for a minimum post size of 50 x 50 x 2 5mm up to a maximum height of 3 0m. Usually 400 450 or 600mm but any value can be used up to 610mm max usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size. Long lengths are readily available. For example the highlighted cell below shows that a 2 x 6 southern yellow pine joist with a grade of 2 and spaced 24 apart can have a maximum span of 10 feet 0 inches 10 0 if you are designing your structure to support a plaster ceiling.

For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. 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 47 x 220 5 04 4 85.