Turning Basement into Studio Apartment


  #1  
Old 08-16-13, 12:45 PM
J
Member
Thread Starter
Join Date: Aug 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Turning Basement into Studio Apartment

Hello everyone. This is my first time trying a forum of any kind so hopefully this goes well. I recently bought an 1868 church and gutted it to turn it into my home. I need to turn the basement into a studio apartment to live in while I do the rest of the reno, which will probably take 18-24 months. My dilemma is choosing the best way to install the new floor. The basement already has about 3 inches of concrete that is in good shape but very uneven. One contractor told me to drop 5" of new concrete on top of the old and then build from there. That would cost $3500. I already have a bunch of 2x10's and wondered if it would be better to install a subfloor, ripping them as needed to level the floor out. If so, what should I use between the concrete and the new wooden subfloor to eliminate mold, mildew, and moisture? I plan to spray foam the cement walls but I'm not sure what to do about the floor. I am on a shoe string budget and I could start the subfloor now because I have all the 2x10's already. Another reason I like the subfloor idea is because I can run plumbing easier. Any thoughts or ideas are greatly appreciated. Thanks.
 
  #2  
Old 08-16-13, 02:57 PM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,180
Received 1,278 Upvotes on 1,217 Posts
Welcome to the forums.

Have you done a moisture test on the concrete floor? Also, are the 2x10s pressure treated?
 
  #3  
Old 08-16-13, 06:01 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 39 Upvotes on 31 Posts
Unless this is way out in the sticks you WILL need to have a plan and a building permit. You MUST have a minimum of two means of egress (escape) from any room that is used for sleeping.
 
  #4  
Old 08-16-13, 07:28 PM
J
Member
Thread Starter
Join Date: Aug 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
The 2x10's are plain yellow pine, not treated. I'm hoping for an option that will allow me to use them rather than get PT. Also, I have a building permit in place already. I have not done a moisture test. Is that when you are tape the plastic down flow 24 hours? Thanks.
 
  #5  
Old 08-17-13, 06:21 PM
G
Member
Join Date: Mar 2013
Location: USA
Posts: 412
Upvotes: 0
Received 0 Upvotes on 0 Posts
You have a few choices. Check with local B.D. inspector: foamboard with a plywood covering; dimpled membrane (Delta FL, Enkadrain, etc.) then foamboard, or Dricore then foamboard. All include foam to separate the difference in temperatures to prevent condensation. http://www.buildingscience.com/docum...g-your-basment

BSI-003: Concrete Floor Problems — Building Science Information

The slab (6' below-grade) is about 10*F warmer than surface temps; Average Shallow GroundWater Temperatures | Ecosystems Research | US EPA

Gary
 
  #6  
Old 08-19-13, 11:41 AM
J
Member
Thread Starter
Join Date: Aug 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
What if...

What if I lay a 6 mil layer of plastic (or similar) down for moisture/vapor barrier then frame the subfloor? I would rip down my 2 x 10's to about 3" on one end and about 6" on the other to level the floor. The floor joists would sit directly on the plastic and directly on the concrete so the floor would be very sturdy. I would have a 3"-6" area that I would either spray foam or using batting to insulate, then sheet with OSB like a traditional floor. I could run my plumbing in the floor for the kitchen, bathroom, and laundry room. Would the plastic protect the joists well enough and what are your thoughts on this approach overall? Thanks in advance.
 
  #7  
Old 08-19-13, 11:45 AM
J
Member
Thread Starter
Join Date: Aug 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Gary,

In the scenarios you mentioned how would I go about leveling the floor? I have an inconsistant difference of about 3" between highest and lowest points of existing concrete. This is why I though ripping the 2x10's down would be a good option, as I already have them and I can level the whole floor. Thoughts?
 
  #8  
Old 08-20-13, 11:18 AM
G
Member
Join Date: Mar 2013
Location: USA
Posts: 412
Upvotes: 0
Received 0 Upvotes on 0 Posts
Wood joists (R-1.2 per inch) sitting directly on cold concrete with spring/summer temp difference for your location could cause condensation on the wood. Better still; strips of foamboard under the joists, on plastic over whole floor; set in waterproof mastic for complete air-sealing from basement air/humidity. The wood would be protected, any condensation on plastic would not harm it for those few months. Rip the joist to level floor, check with local inspector for attachment requirements, egress approval, as said

Gary.
 
 

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