Not more than 0 25.
Floor joist spans c24.
This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction.
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.
Maximum floor joist span for no.
C24 and i joists the weight of the timber floor itself consists of the timber joists the plasterboard ceiling underneath it except for suspended timber ground floors the floorboards and the nails or screws used to fix both of the aforementioned coverings.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
Other span tables are based on the guidance given.
True floor joist span calculations can only be made by a structural engineer or contractor.
This means that some values are slightly more conservative than span tables from other sources if those do not include the amended guidance.
Floor joist span tables for surveyors floor construction.
2 grade of douglas fir are indicated below.
Span tables for domestic floor joists to bs 5268 7 1 note.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
Imposed load not exceeding qk 1 5 kn m2 or qk 0 90 kn.
This means that some values are slightly more conservative than span tables from other sources if those do not include the amended guidance.
Two additional joists required bold text normal bearing of 40mm to be doubled.
If supporting lightweight partitions running parallel to joists provide two additional joists under each partition.
Permissible clear spans for domestic floor joists.
Span tables ceiling joists imposed load 0 25 kn m c24 timber permissible clear spans for ceiling joists to bs 5268 7 3 imposed load.
Dead load weight of structure and fixed loads 10 lbs ft 2.
Service class 1 or 2.
Find the column for your dead load and spacing and the row for your timber size to find the permissible clear span in metres.
Live load is weight of furniture wind snow and more.
Span tables flat roof joists imposed load 0 75 kn m c24 timber permissible clear spans for flat roof joists to bs 5268 7 2 imposed load 0 75 kn m.
Dead load per square metre in kn m supported by joists.
1 psf lb f ft 2 47 88 n m 2.
