Can I Safely Cut Through My Foundation? - Building & Construction - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction


Thread Tools Display Modes
Old 11-29-2008, 10:33 PM   #1
Join Date: Nov 2008
Posts: 1
Rewards Points: 10

Can I safely cut through my foundation?

Our home was originally designed with one room, first floor, as either a study or as a bedroom. If it was designated as a bedroom, then the adjoining bathroom was complete with a shower.

We chose, at the time of construction, to use the room as a study and the bathroom was built with a closet rather than as a shower.

We would now like to convert the closet to a shower. The south wall of this closet is the back of the shower for the master suite. The water supply for the master shower is in the wall between the two rooms (master shower/second bath closet). A plumbing vent is also in this shared wall.

Connecting the water supply for the second shower presents no problem.

Our problem is there is no drain in the closet. I'm considering breaking through the floor of the closet and connecting a drain into the vent of the master shower.

Our slab is a post-stressed slab and is 15 years old therefore it is quite hard.

My questions are:
1. What risks are associated with cutting a hole, through the slab, that is large enough to gain access to the drain system?

2. Will a connection to the vent properly serve as a drain to the shower?

It has been suggested that I just break out enough space in the floor to install the p-trap so that its exhaust runs across the floor to a connection in the vent, about 18" away. That would mean raising the floor of the shower considerably. I don't like that solution, but I'm not excited about cutting a 20" hole in my foundation.

Thanks for you assistance


grubbyjeans is offline   Reply With Quote
Old 11-29-2008, 11:53 PM   #2
Registered User
Termite's Avatar
Join Date: Apr 2008
Posts: 6,520
Rewards Points: 2,000

Cutting into a post-tensioned slab is definately not a DIY job. If you cut into a cable tendon, you'll have a slab failure at the least, and a bad injury at the worst. They're nothing to mess with.

I never advocate raising a shower to facilitate draining it above the slab, but in this case it might be a good idea.

I wouldn't say it would be a good idea to use the master shower's vent as a drain, although it might work. Hard to say without actually looking at it.


Termite is offline   Reply With Quote
Old 12-01-2008, 04:08 AM   #3
Lansing's Avatar
Join Date: May 2008
Location: Nova Scotia, Canada
Posts: 52
Rewards Points: 75

Agreed with thekctermite...Do not cut your concrete floor...Do your shower drain p-trap above the floor there now and build up the new floor to suit...The vent is also a drain so it should work long as you set a p-trap in the line to it to stop sewer gas backing up in the shower...

The low cost to rough in these abs pipes before pouring the concrete slab is well worth it...
When the time comes for you to leave this world
the only thing you get to keep is what you gave away...
Lansing is offline   Reply With Quote

foundation , plumbing , shower

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Re-grading around foundation? robertr4836 Landscaping & Lawn Care 10 05-23-2009 05:34 PM
Floor Joists Lifting Off Foundation Walls?! cbeingessner Building & Construction 2 06-12-2008 08:39 AM
concrete foundation with a crawl space agrenvik Building & Construction 1 03-25-2008 08:27 PM
Foundation drain and sump pump slatergrl Plumbing 3 02-10-2008 09:36 AM
Stone foundation for a small shack andrgo Building & Construction 10 09-13-2007 01:49 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1