How thick do loft joists need to be?
Before you start laying boards, check the depth of your insulation. Building Regulations guidelines recommend a minimum 270mm thickness of insulation blanket. But joists are usually no more than 100mm deep, so this would be impossible to achieve and still put a floor on top.
What size should attic joists be?
Attics With Existing Flooring In attics built purely for storage purposes, you may find 2 x 6 ceiling joists, or in some cases, even 2 x 4 joists. Flooring for dead loads may not be sufficient for live loads—the loads created by people and the features of living space.
How thick should a floor joist be?
Joists in home construction are usually made with 2-by-10 or 2-by-12 lumber, which are 9 1/4 and 11 1/4 inches deep, respectively.
How wide are loft joists?
The two most common joist spacings are 400 and 600mm. If your loft floor joist spacings are 400mm, choose either: 370/380mm wide loft rolls, or. 11400mm wide loft rolls to be cut into three smaller rolls.
What size do floor joists need to be UK?
Joists are to have minimum end bearing of 40mm. 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/m² or a concentrated load of 1.4 kN.
What size do floor joists have to be?
Spacing (distance apart) of joists – centres
| Size of joist mm | 400mm | 600mm |
|---|---|---|
| 38 x 220 | 4.16 | 3.42 |
| 38 x 235 | 4.43 | 3.64 |
| 47 x 97 | 1.92 | 1.46 |
| 47 x 122 | 2.55 | 2.09 |
What size is floor joists?
Floor joists range from 2×8 to 2×12. It is less common to see joists that are 2×6, even though they are included in joist span tables. Older homes are more likely to use 2×6 for joist framing. There is no “typical” floor joist size because there are so many variables regarding the floor framing.
What size do ceiling joists need to be?
Though there is no standard joist size for the ceilings in all buildings, most average homes use ceiling joists in a board size of 2-by-6 inches. The range of joist sizes used in homes varies though, between 2-by-4 inches and 2-by-12 inches.
Can I use 2×8 for floor joist?
The rule of thumb is 1″ of depth for each foot of run. EX an 8′ span should have a 2×8 joist. The same rule of thumb applies to door and window headers but you should use 4x wood.
What size joist do I need?
For example, assume the clear span is 15 feet 6 inches. Round up to 16 and divide this span by 2, giving you 8. Next, add 2 to get the required joist depth. In this example, 8 + 2 = 10, so a 2×12 floor joist will be required (it’s important to use the actual lumber dimensions, not the nominal dimensions).
What size floor joist do I need?
How thick should ceiling joists be?
Standard Size of Joists Though there is no standard joist size for the ceilings in all buildings, most average homes use ceiling joists in a board size of 2-by-6 inches. The range of joist sizes used in homes varies though, between 2-by-4 inches and 2-by-12 inches.
What size floor joist do I need for loft flooring?
Simply click here to return to Ask The Expert. I’m doing my investigation to put down some loft flooring. All the loft board packs that i have seen, mainly B&Q and Homebase, require the joist centre span to be no more than 450mm wide.
Can I put a floor above my Ceiling joists?
As a general principle, leave your ceiling joists alone and install a new floor above them, but see 3 below 3. If you are seriously considering a loft conversion get the thing designed by a someone who has designed loft conversions in the past and is up to date with the regs and building practices concerned.
Can I use 8×2 joists to pre-empt a loft conversion?
There wouldn’t be any point in putting 8×2 joists in to pre-empt a loft conversion as when the structural drawings they wont always specify an 8×2 joist. Cheers Obviously depending on loads and where you put them,assuming you are storing normal xmas decs,winter duvets and memorabilia etc thats fine,especially heavy stuff towards end of joist span.
Will you consider options for 25mm gap between floor joists?
Will consider options further, may have to relent and get somebody to design it properly. we do alot of loft conversions and the floors have to be totally dependent of your existing joist with a 25mm gap.