New bathroom install Q. - 4" PVC against joists.


  #1  
Old 09-28-05, 09:10 AM
JetIgniter2k
Visiting Guest
Posts: n/a
New bathroom install Q. - 4" PVC against joists.

My house is a ranch with a huge unfinished attic. I would like to turn it into 600 square feet of livable space. Building a few walls, running electrical, drywall, flooring, etc. isn't really a big deal. But I would really like to have a second bathroom in the house. Again, not a big deal, I'm a general contractor with 5 years experience. But it seems i've hit a little snag with how to run the 4" PVC for the drain system. The only way to get it to the existing stack is to go aginst the 2x8 joists, about 15 joists to be exact. Thats a pretty big chunk of wood missing and a pretty big span. i could run the pipe to the closest 1st. floor closet and bury it in there, but that still means about 8 joists. And that would put a very anoying obsticle in the middle of my basement workshop.
Does anyone know of a way to reinforce the joists so i can run my 4" pipe to the existing stack?
Here's my theory, I'm not a structural engineer but i think it would be more than enough bracing. I start with an 8" tall x 24" long x 3/16" thick steel plate. Cut a 4" hole in the center of that; well not dead center, i still would have to take in account my 1/4"/ft. slope, but basicly where the pipe would fall on the joist. Then i drill ten holes, five on either side of my 4" hole, in an X pattern. Then place one of these plates on either side of the joist and sandwich it all together with ten 1/2" bolts (NOT lag screws). That would make a combined total of 3/8" x 4" piece of steel plus the 2x4 leftover wood around my pipe. BTW - making 30 of these plates isn't a big deal, I have a CNC plasma cutter capable of severing 1-1/4" steel. If you guys don't think thats enough, i could make the plates thicker or weld flat bars accross the top and bottom to make each plate channel bar and the sandwiched product ecentially an I-beam. Any thoughts?
Thanks,
Bryan
 
  #2  
Old 09-28-05, 11:59 AM
G
Member
Join Date: Sep 2002
Location: South West PA
Posts: 73
Upvotes: 0
Received 0 Upvotes on 0 Posts
Go down and up

Consider dropping a 3" drain down through the wall into the basement (assumng you have a basement) and then under the joists in the basement to the existing stack. A 3" drain should handle your attic bath. You could then go up through the roof with the same 3" pipe for your bathrooms vent.
I don't know if this has any code implications.
 
  #3  
Old 09-28-05, 03:58 PM
wrmiii's Avatar
Member
Join Date: Jun 2002
Location: West Texas
Posts: 245
Upvotes: 0
Received 0 Upvotes on 0 Posts
Oh my Gosh

Jet: From your description I think your saying that the only available pipe is approximately twenty feet from the perimeter of this new space you would like to inhabit. That your drain line would run at ninety degrees too the existing ceiling joists.
I see several issues, a 2 x 8 is only 7 ½", running a 4" PVC drain line (Which is 4 ½" o.d.) at a distance of approximately 20 feet requires ( @ an 1/8" per foot on 4" ) a 2 ½" drop over this distance. This leaves a distance of ½" for fitting make up. This route would not work.
Now for the bigger problem. This four inch pipe you would like to tie into is undoubtedly the vent stack for the one bathroom you do have. No code will allow a soil line to empty into a vent stack. O.K., now I can’t give you all of this negative feed back without a few possible solutions or my friends on here may think I’m a Democrat. Look for an area directly below this new area, possibly a closet, a stem wall, some area that could be furrowed out to conceal a new drain line from the attic area to your basement If you have a building drain in the basement area below the commode on the first floor this is your spot. If the drain is not accessible from your basement then turn the new drain line to the exterior of your house and have it exit just below the frost line for your area and tie into the building sewer. And silly you! You have been a general contractor for five years. I know you have worked with many plumbers. Simply ask one to stop by and give you their opinion. Trust me! All plumbers love the general contractors. Good Luck and keep us all posted of your progress.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: