Cutting floor joists to run soil pipe through..

[pavsid]

Hi all, i'm looking to relocate our toilet to the other side of the bathroom, backing on to an interior wall. Preferably i'd like to keep the soil pipe hidden, without having to run it around the room to the opposite side where the exterior wall and the existing soil pipe is.

So, i'd like to run it under the floor boards. I've taken up the boards, and there the joists are running across where the pipe needs to run. The joists are 100mm deep and there is a 125mm gap between them and the concrete below (ground floor bathroom).

The soil pipe would have to run about 2.5m to the other side of the bathroom to the outside, so there isn't enough space under the joists to give it the adequate angle it needs.

So, is it possible to cut some of the joists to allow it to run under the floorboards, assuming I prop them up at the same height against the concrete below? Or is this a big no-no??!

Any help or suggestions would be appreciated!

 

[tony1851]

Possible, but it depends on exactly how much you want to cut from underneath the joist, the distance of the cut from the end of the joist, and the overall span of the joist.

In practice and as a vey rough guess, I would think it unlikely you could cut more than 20-25mm away, and that would be under the most favourable circumstances.

 

[pavsid]

Hmm, damn, ok thanks Tony. Any other ideas of how we could get the soil pipe out rather than run it round the room? Or is this a question better asked in the plumbing forum?

 

[JohnD]

I'd give a great deal of thought to putting the WC nearer the soil pipe.

If it was worth the (considerable) effort, you could take up the whole floor and re-lay the joists the other way.

 

[pavsid]

I'd give a great deal of thought to putting the WC nearer the soil pipe.

If it was worth the (considerable) effort, you could take up the whole floor and re-lay the joists the other way.

Gosh, that does sound like some considerable effort!

What about propping up the joist and bolting it to the concrete below either side of the gap which is cut out of it wide enough for the pipe? Would that not prevent downward and sideways movement? Does that make sense, or shall i draw a picture?!

 

[pavsid]

I'd give a great deal of thought to putting the WC nearer the soil pipe.

If it was worth the (considerable) effort, you could take up the whole floor and re-lay the joists the other way.

Gosh, that does sound like some considerable effort!

What about propping up the joist and bolting it to the concrete below either side of the gap which is cut out of it wide enough for the pipe? Would that not prevent downward and sideways movement? Does that make sense, or shall i draw a picture?!

Or, isn't something like this possible?

http://hostedmedia.reimanpub.com/TFH/Step-By-Step/FH00JAU_JOIWOR_06.JPG

http://www.homeownersnetwork.com/wp...9-ceiling-joist-rafter-opening-less-4-ft1.jpg

 

[pavsid]

Been in touch with a building control officer, and they say that a sleeper wall to rest the cut joists on would suffice.

That would save doubling up the full-length joists and adding trimmer joists.

Anybody have anything to add?