Taking down wall Single storey flat roof office

[dbyg]

Hi
Hope someone can shed some guidance on this matter

A mate has asked me to take down part of a wall to make an arch between 2 offices

The building is a single storey flat asphalt roof
The wall to come down is a single brick interior wall skimmed with half inch plaster

Took part of the ceiling down to check the roof joists they run across the opposite direction of the wall to come down with no joist joints on the said wall so im presuming the joists run the full length of the building

Am I safe to take down the wall without the need to put a rsj support in place

 

[DevilDamo]

If the flat roof joists run in the same direction (i.e. parallel) with the wall, then the wall would be considered to be non-load bearing and thus not resulting in having to insert a beam or a building regulation application.

 

[RonnyRaygun]

Sounds like he's saying the joists are running perpendicular to the wall?

If they're sitting on the wall then it is load bearing, although as the joists are continuous over the wall it is possible that the joists would span the whole distance if the wall was removed. That depends on the load from the roof, joist centres, sizes and span.

 

[DevilDamo]

Agreed.

This is the part that was confusing, which could be one of two things...

Hi
Took part of the ceiling down to check the roof joists they run across the opposite direction of the wall to come down with no joist joints on the said wall so im presuming the joists run the full length of the building

So the joists either run in the opposite direction (i.e. perpendicular) or the run the full length of the building (i.e. do not sit on this wall), thus making them run parallel.

 

[theoldun]

Whilst the joists may run full span, that does not mean that they have been sized to run full span. They may only have been sized to be supported on the spline wall that you wish to pull down. If this is the case, and the supporting wall is removed, then over a period of time the joists will sag.
If you care to post the size of joists, centres of joists and overall clear span, then will let you know whether they will suffice. Confirm is roof finish asphalt or felt?
oldun.

 

[DevilDamo]

If the joists run full span... as does this single skin brick wall... what support (if any) would that offer to the joists? Nothing. Ok, apart from maybe two joists side by side.

Or... you're assuming this wall to be load-bearing, thus the joists running perpendicular to the wall?

 

[RonnyRaygun]

Took part of the ceiling down to check the roof joists they run across the opposite direction of the wall to come down with no joist joints on the said wall so im presuming the joists run the full length of the building

From this I'm sure he means that the joists run over the top of the wall. Ie they are continuous over the wall but don't end at the wall (no joist joints).

So if they are touching the head of the wall then it is load bearing, but the joists might still have the capacity to span the full length of the building...hopefully he'll return and supply us with the info we need.

Must be a short building if the joists span full length though...