2 posts / 0 new
Last post
rephil34
new bath drain

is there a proper way to run a 2" drain perpendicular to floor joists?
if i laminate 3/4" plywood to joists is it ok to drill 21/2" holes to run a 2" drain?

MLBSF
Re: new bath drain

you can not make a hole bigger than 2/3 the height of the joist and the top and bottom of the hole must be at least 2" from the top and botom of the joist. so to answer your question, the largest hole you can drill in a 2x8 floor joist is 2 1/4" and the largest hole you can drill in a 2x10 floor joist is a 3" hole while making sure to stay 2" from the top and bottom of the joist.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.