passing 40mm pipe through wall - use 50mm core drill

garyo · Posted: Tue Feb 21, 2012 10:50 pm

When coring our a hole in an external wall for a 40mm waste pipe, would you use a 50mm core bit so that you could use 5mm of sealant all round?

Thanks

mickyg · Posted: Tue Feb 21, 2012 10:54 pm

as long as the core is bigger than the pipe it doesnt really matter !

TicklyT · Posted: Tue Feb 21, 2012 11:09 pm

£1 to a pinch of s*** says your nominal 40mm pipe isn't actually 40mm OD.

and a chance to win your money back - another £1 says the hole won't finish dead on 50mm either.

If the hole isn't looking dead square at the pipe run you'll be glad of a bit of clearance anyway.

vicvapour · Posted: Tue Feb 21, 2012 11:13 pm

garyo wrote:

When coring our a hole in an external wall for a 40mm waste pipe, would you use a 50mm core bit so that you could use 5mm of sealant all round?

Thanks

Normally you would use a 44mm but 50 is fine as said previously, as long as it IS actually bigger, is doesn't really matter, just a little bit more making good to do really mate.

garyo · Posted: Wed Feb 22, 2012 8:27 am

Cheers guys, I was thinking that a 40mm hole would be too small because that would leave zero space to get sealant in. I didn't realise you could get 44's... I'll go buy one.