P5 board and perimeter support?

[Digmixfill]

I've just ordered the first set of posi joists - more visible progress :)

 

I was planning to use Egger Protect for the first floor, so read the installation guide etc. Had a query regarding short edge support and joist overhang so emailed Egger.

 

I'm going to end up with a 75mm gap between the end joists and the walls - like this snippet stolen from NHBC.

 

 

Egger say that the short ends of all boards must be supported and have said I would need to install noggins for the gap.

 

My google fu is weak and I can't find any examples on t'web for people doing this.  Anyone dealt with this?

[Oz07]

Probably okay at that. If dry lined then 25mm is gone minimum to that, then 20mm to skirting. That leaves 30mm overhanging joist. Are you really going to be able to apply point loads to 30mm and make a floor board deflect?

Edited February 26, 2021 by Oz07

[Digmixfill]

I was surprised. I expected Egger to say that it would be fine if, as you mention, plaster/drywall and skirting are added - reducing the gap.

The reply I had was the BDA agrement and a quote from a section:

 

"butt joints shall be staggered and supported by noggins or joists;
the particleboards shall be fixed and supported on the perimeter edges of the short-ends by noggins or joists. Although long edges do not require
intermediate support between joists, support noggings shall be fixed at floor perimeters where unsupported edges abut a wall"

 

Along with "You are correct in what you say about the short ends falling on the joist, where this is not possible an additional nogging must be fitted to support the short end."

 

 

[Oz07]

Nail a bit of 2x2 to top chord, leave a 25mm gap all around if you like. Job done. 

 

They've said what they have to say. It reality we know it will be fine. 

[Digmixfill]

One of possibilities i've pondered is a 47mm lump of wood glued and screwed to the length of both chords. Minimise the gap for P5 and ceiling plasterboard.

With all the do's and don'ts of webbed joists i'm not sure if that's allowed? You are allowed to sister them by screwing together, so I don't see why it wouldn't be allowed.

 

[Oz07]

I'm sure the building won't collapse if you do it. Honestly this is one of those over worrying moments ask @ToughButterCup

[trialuser]

could you just get an extra joist and fiddle the end gaps a bit

[Digmixfill]

4 hours ago, Oz07 said:

I'm sure the building won't collapse if you do it. Honestly this is one of those over worrying moments ask @ToughButterCup

So true.

I am ever so good at over thinking most things on this conversion.

 

43 minutes ago, trialuser said:

could you just get an extra joist and fiddle the end gaps a bit

Yes. The 75mm spacing is because of the wings on the joist hangers. I could ditch the current and switch to something like a teco fhm for the masonry side and a hidden flange for the ledger plate side.