Drilling holes in joist

[600rob]

Im considering putting a hole through this joist in the position arrowed. It will be for a shower waste pipe

IMG-20210629-WA0001

• 600rob
• 1 Jul 2021

The joist itself is 62mm thick by 205mm tall. Its at least 3 metres long starting from the wall and i want to see if is feasible to put a hole in thats big enough to take a 50mm waste pipe

Can someone advise what the correct calculation and rules are for putting a hole in a joist or where i can find accurate info for this

 

[jeds]

Technically speaking it's a no; too close to the end of the joist. But I've seen hundreds of waste holes in similar positions that cause no issue. 63x200 joists over a 3m span is well within the joist capacity. If it were mine and I really couldn't get a route elsewhere I'd do it.

My advice is fix 2 pieces of 18mm ply either side, glued and screwed. Make them as big as you can get in. Then core the hole through the joist and ply.

 

[600rob]

Thanks Jeds will try this

Technically speaking it's a no; too close to the end of the joist. But I've seen hundreds of waste holes in similar positions that cause no issue. 63x200 joists over a 3m span is well within the joist capacity. If it were mine and I really couldn't get a route elsewhere I'd do it.

My advice is fix 2 pieces of 18mm ply either side, glued and screwed. Make them as big as you can get in. Then core the hole through the joist and ply.

Thanks for the reply Jeds, Will try this.
Cheers