Tub Rough In Measurements

Reply

  #1  
Old 04-12-07, 12:06 AM
Member
Thread Starter
Join Date: Oct 2006
Location: USA
Posts: 66
Tub Rough In Measurements

I'm doing the rough-in for a bathroom over an 18 inch crawlspace. The entire sub-floor is removed and I have free access. The tub and enclosure will be 60x32, but the exact model hasn't been selected. It would be nice to have manufacturer's rough-in directions, but it ain't going to happen. So what are the rough-in measurements for a "standard" tub drain?

I understand the tub drain should be centered 1 1/2" from the faucet wall studs. However, the distance from the rear wall studs is unclear. I've seen both a 14 1/2" and a 15" center referenced, and a 16" center makes more sense to me. What is the correct rear wall distance for a "standard" 32" tub drain?

How far below the floor should I terminate the P-trap to allow connection to the drain assembly? I've read 3", but that seems a bit tight to me.

Since the drain assembly and P-trap will be inaccessible, they will both be solvent welded. The drain assembly will be attached to the tub before it's set in. Should I still cut a 6x12 access hole in the floor, or would a small hole for the end of the drain assembly be sufficient. This is unheated crawlspace and I'm thinking heat loss. No one is going to work in an 18" crawlspace. They'll tear the wall out first.


In summary, 1 1/2" x 15" center (from studs), P-trap ends 3" below the floor, and no cut out. Does this sound about right?

Thanks,
Barry
 
Sponsored Links
  #2  
Old 04-12-07, 04:10 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Likes Received: 1
Barry: Half the distance to the goal, remember that. If you use a 32" tub, then 16" from the back wall; likewise on a 30", go 15". I am not an advocate of solvent welding the ptrap on a shower. You need wiggle room in order to get the hole perfect. You won't install the tub with the drain attached, so get ready to install it afterwards. Dig the hole. The ptrap will extend probably 6" below the bottom of the tub, since the drain will be taking up 2" by itself. I would definitely leave some accesss in the wall on the supply side from the floor to the control valve. That way you can fit the trap and do maintenance work on the valve at a later date if necessary.
 
  #3  
Old 04-12-07, 06:56 AM
Join Date: Dec 2005
Location: USA
Posts: 3,188
Barry - If you have a few tubs in mind you can visit the manufacturer's website. Most have installation instructions available for download.
 
  #4  
Old 04-12-07, 09:28 AM
shacko's Avatar
Member
Join Date: Aug 2005
Location: Baltimore County Maryland
Posts: 2,138
Tub rough-in

There is no standard rough-in for a tub, since you have access in the crawl space your best bet is to run a pipe near where the tub will be and finish the install after you put the tub in place, 18in. is plenty of room to work on the connection.

Cut a hole in the floor, I like 12x8 that may give you room to work on the hook-up without going into the crawl space.

Btw, the opening for a 60in. tub should be approx. 60 1/4, the width will depend on your installation, you can't rough it in to the actual dimensions. it won't work. Best that I can do, lots of luck.

...............................................................
"If all else fails, read the directions"
 
  #5  
Old 04-12-07, 10:40 AM
Member
Thread Starter
Join Date: Oct 2006
Location: USA
Posts: 66
Unfortunately, there is no word on the exact tub yet. Based on what everyone has said, I'll get the pipe near the tub, put the floor down and cut a hole. In fact the faucet wall hasn't even been built yet. Likewise, waiting for exact tub dimensions. Sounds like I need details PDQ.

In our area, I believe code forbids threaded connections in inaccessible areas. An 18" crawlspace is considered inacccessible (by code), but an access panel plus a hole might be the ticket.

Thanks for all the suggestions. They do help.

Barry
 
  #6  
Old 04-12-07, 11:08 AM
Join Date: Dec 2005
Location: USA
Posts: 3,188
Barry - I just helped my son install a jetted tub. We stubbed the drain in the general vicinity of where it was needed. I cut a 16"X16" hatch in the subfloor. Once the tub was in place, we installed the trap (mechanical swivel type) and lined it up to the drain. A bit of a tight fit, but definitely accessible.
 
Reply

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 On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes