Anyone know about joists? Plumber has drilled a big hole in ours...

[gracegrape]

We are having our bathroom remodelled and an ensuite built. We moved out for a few days while this was being done as there was no water/toilet. When we returned, we noticed that the plumber has fitted a new waste pipe by drilling through two of our floor joists. I understand that it is permissible to make a hole of up to 1/4 of the depth of the joist but this is definitely bigger (a 2" hole in a 7" joist). Does anyone have any advice about what we should do next?
Thanks!!

drilling a hole is generally OK. Cutting a notch (the alternative) is very bad (but sadly not uncommon)

What is the span of the joist (between the two walls it stands on)?

Dh said (without seeing it) probably ok.

Thanks both. The span of the joist is about 25ft. There is a supporting wall below about 14ft in, which we are hoping to knock down and replace with an RSJ in the future. The holes (in 2 joists) are almost directly above this wall.

Sounds like it should be ok, but DP is just concerned as he thinks we need building regs to sign off on the en-suite as it's an addition.

How far from the support the joist sits on is the hole? The close it is to the support, the less you have to sorry about. What are the gaps between the joists. If you have 250-300mm centre joists then the effect of the hole is less pronounced than 400mm centre joists.

In short, its not necessarily the end of the world but if you want to feel more comfortable about this you may want to ask the plumber to attached some timber to the joist above or below the drill hole to strengthen it.

The holes (in 2 joists) are almost directly above this wall.

So I do not believe it is a concern.

oops sorry. missed it. :)