sleeper wall distance

[DIYedboy]

I am proposing a 4 metre deep extension on the rear of my house, I want the floor to be suspended timber, so I will have to build sleeper walls, but how many?

 

[tony1851]

Depends on the size and spacing of your joists.

 

[DIYedboy]

Let's say joists to be 4 x 2's

 

[dann09]

At 16" c/c, using 7 x 2 or 8 x 2 joists it should work - set noggins in the centre or at 1.3m from each end.

Before fixing the boarding check for sway or bounce.

 

[theoldun]

Let's say joists to be 4 x 2's

Lets say C16 47x125 regulised to 120 at 400 centres will span up to 2500.
47x100 at 400 centres will only span 1.87 Your choice.
Would be cheaper and easier to build in and fit C16 47x200 regulised to 195 and no sleeper walls.
Don't forget about your insulation
Regards oldun

 

[tony1851]

Would be easier to build in and fit C16 47x200

Yes. If you put a central sleeper wall in, it is difficult to get joists perfectly level. The floor will also feel 'light'. The deeper joists will make for a heavier and probably more rigid floor (that's assuming you've got adequate clearance underneath for ventilation). Remember to incorporate central strutting.

 

[DIYedboy]

Thanks lads, I will have a problem with clearance beneath the joists due to existing ground level outside, so 4x2's with a sleeper wall will reduce the problem