Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Wood beam span table uk.
Span calculator for wood joists and rafters also available for the android os.
The numbers in gray indicate the distance between the support posts.
Headers beams.
Dimensional lumber deck beam span chart.
Span tables for domestic floor joists to bs 5268 7 1 note.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Surveyors span tables for designing roof rafters.
Other span tables are based on the guidance given in bs 5268 7 1 which is a uniformly distributed load of 1 5kn m for spans greater than 2400 mm and 3 6 kn load per metre width of floor for spans less than 2400 mm to ensure that very small joist sizes do not result from the calculations for smaller spans.
You need to measure the complete span of your floor joists together with the distance between them the centres and the size of the timbers.
Allowable load tables tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications.
Also available for the android os.
They refer to a dead load of not more than 0 5kn m 2 excluding the weight of the joist and an imposed load not exceeding 1 5 kn m 2.
The following span tables are indicative of some of the spans required for domestic floor joists where c16 and c24 strength classes are used.
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.
A double 2x12 beam can span 12 feet.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
This means that some values are slightly more conservative than span tables from other sources if those do not include the amended guidance.
Centres is the maximum centres that this joist can be used for in this application.
For pitched roofs flat roofs and ceiling joists.
This table is for a dead load of more than 0 25 but not more than 0 50 and allows for an imposed loading of no more than 1 5 kn sq m.
If a joist s max.
It is assumed that for built in joists that the masonry is 100mm wide and for joists on hangers the hanger has a 75mm bottom plate.
When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches.
0 003 x engineering span or 12mm whichever is lesser.
