Finishing block basement

Reply

  #1  
Old 01-02-17, 10:20 AM
B
Member
Thread Starter
Join Date: Nov 2015
Posts: 14
Received 0 Votes on 0 Posts
Finishing block basement

Hello again,

Simple question this time. I plan to put cedar tongue and groove planks over my basement wall in a room I'm finishing. The block has the white moisture/mold resist paint on it and I've never had any issue with a damp, wet or humid basement. I plan to rip a couple 2x4s in half and attach them to my wall to nail the planks to and insulate between those strips with expanded polystyrene board.

Do I need any types of vapor barrier against the block?
 
Sponsored Links
  #2  
Old 01-02-17, 10:46 AM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 47,663
Received 321 Votes on 285 Posts
IMO it's better to erect a stud wall maybe an inch off of the foundation wall. That gives you room for electrical and prevents you from punching holes in the foundation wall [nails or tapcons]
 
  #3  
Old 01-02-17, 11:55 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,580
Received 94 Votes on 83 Posts
I would put rigid foam on the block and tape the seams in order to provide an air barrier, vapor retarder and thermal break. Then I would put up a stud wall as close as I could and insulate the bays with Roxul. The I would put the cedar on the inside of the stud wall.
 
  #4  
Old 01-02-17, 12:13 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 6,558
Received 371 Votes on 346 Posts
Or skip the foam, pull the wall away from the block leaving it open at the top to allow circulation.

Foam is so expensive and leaving it open at the top eliminates any moisture issues.
 
  #5  
Old 01-02-17, 01:27 PM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,580
Received 94 Votes on 83 Posts
Skipping the foam and building the stud wall away from the block creates a condensation surface on the inside of the block. Leaving it open at the top would then be essential so it could dry to the inside.
 
  #6  
Old 01-02-17, 02:56 PM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 6,558
Received 371 Votes on 346 Posts
I cant recall how much adding the foam to my basement was going to run, if I recall 1" thick foam is like $20 a sheet, 1400 sq ft of new space adds up.

I understand the concept but get into a lot of "discussions" regarding the cost hit vs just allowing some ventilation behind the wall to remove moisture.

I understand it's not as "tight" but on the flip side it's 95% better than what the bare cement wall was before anything was done.
 
  #7  
Old 01-02-17, 03:18 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 26,017
Received 675 Votes on 624 Posts
The space behind the wall needs to be fireblocked (at the top) regardless of whether it is foamed or not... it shouldn't just be left open to the floor joists.
 
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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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