1 psf lb f ft 2 47 88 n m 2.
Depth of floor joists uk.
Floor joists ceiling joists flat roof joists rafters purlin span tables for domestic floor joists to bs 5268 7 1 note.
As a general rule of thumb the overall length of the joist span divided by 2 1 equals the depth of the joists.
1 ft 0 3048 m.
Note this only works in imperial and is for domestic loadings only.
The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction.
True floor joist span calculations can only be made by a structural engineer or contractor.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
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.
Eg joists spans 14 ft wall to wall dived by 2 1 8.
The actual width of those boards however isn t identical to what their name implies.
Joists are to have minimum end bearing of 40mm.
This means that some values are slightly more conservative than span tables from other sources if those do not include the.
The floor joists comprise the bulk of the floor thickness.
Dead load weight of structure and fixed loads 10 lbs ft 2.
Live load is weight of furniture wind snow and more.
A 2 by 10 joist is really only 9 1 4 inches wide and a 2 by 12 is only 11 1 4 inches wide so depending upon.
The floor joist span tables are based on the loadings given in the amended version of bs 6399 1 which is an imposed load of either a uniformly distributed load of 1 5 kn m or a concentrated load of 1 4 kn.
Therefore joist depth is 8 inches.
The use of engineered floor systems is growing in the uk replacing traditional solid timber floor joists or concrete flooring.
2 grade of douglas fir are indicated below.
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.
All the figures are based on normal domestic floor loadings where the floor construction is typically 18 25mm floor boards sheets with up to 12 5mm thick plasterboard and skim underneath.
