Over spanned ceiling joists

[HotrodCJH]

Hiya,

I have an issue with the ceiling joists on my current self build project.
I have had all calks done and approved by building control, but the inspector has now said my ceiling joist are over spanned.

Currently the joists are 4x2 C24.
They are spanned 5.2m with a bolted double 6x2 binder at 2.6m.

My initial ideas are:

1: Put another couple of binders in at 1.3m and 3.9m along the span. If so what size?

2: Tie the last 600mm of each ceiling joist to the rafter above, effectively reducing the span to 2m. If so what should I tie them together with. Ply/galvanised straps.

Any help would be greatly appreciated.

Chris

Read more: http://www.diynot.com/diy/threads/over-spanned-joists.430764/#ixzz3VgOgUgvP

 

[catlad]

I would do what the inspector likes if I were you, I don't understand the 6x2 double binder bit. I would have thought that 4x2 is plenty for a ceiling.

 

[noseall]

Who designed the ceiling detail?

 

[freddiemercurystwin]

4x2s are woefully inadequate, need something like 50x220. 4x2s indeed!

 

[catlad]

Well fred I was thinking all its holding up is plasterboard as such 4x2 is overkill in my book, but I know you have your own book!!!!!!!!!

 

[noseall]

Well fred I was thinking all its holding up is plasterboard as such 4x2 is overkill in my book, but I know you have your own book!!!!!!!!!

Aw come on Cat, 100mm x 50mm is not even close nor is the ceiling binder.

If people re going to DIY building reg's relevant structures, they should at least come within a sniff of passing. This guy is way off the mark and is throwing ideas out there until he hits the bulls eye. Not a good way to build to reg's.

 

[catlad]

Well nose I am not sure what has been constructed exactly, but I have been led to believe that the span has been halved to 2.6m and if thats the case then I know you would not have a problem hanging plaster board to that.

 

[tony1851]

@OP; what span is the double 6x2?

Assuming the binder is not itself overspanned, then the ceiling joists themselves are fine.

 

[noseall]

Well nose I am not sure what has been constructed exactly, but I have been led to believe that the span has been halved to 2.6m and if thats the case then I know you would not have a problem hanging plaster board to that.

Not even close for 4" x 2".

 

[HotrodCJH]

Ceiling detail was designed by a structural engineer and then passed by structural guys at building control. Just the inspector thats not convinced.

The ceiling binder (2No 6x2 bolted together) sits at the half way point of the ceiling joists. It spans 3m.

Surly this effectively halves the ceiling joist span to 2.6m at catlad said... Right?

 

[tony1851]

Clearly your inspector is a nit.

First, if your SE's calcs have been approved by Building Control's own SE, then that is the end of the matter; the inspector should not meddle in purely structural matters.

Second, your inspector should know that ceiling joists are not critical elements of structure. The worst that can happen is that they deflect just a little too much, and deflection is not a structural matter, it is a serviceability issue, which is different.

Third, he should know that the published span tables on ceiling joists allow for a live load of 0.25 kN/m2 (approx. 5 lbs/sq ft).
If you are not storing stuff up there, there will be no live load, only the dead load of the ceiling, which is very small.

 

[noseall]

Clearly your inspector is a nit.

So is the SE. It is a pants ceiling design whichever way you look at it.

 

[HotrodCJH]

Thanks for your help tony1851.

noseall, I suggest you try and think of some more constructive things to say in future. Three posts any not one bit of useful info.

 

[noseall]

noseall, I suggest you try and think of some more constructive things to say in future. Three posts any not one bit of useful info.

Sack the SE?

 

[catlad]

Noseall? The ceilings in my house built 1960 are 3x2" and span over three metres, they are still straight more than 5 decade's later.