Gypcrete

Reply

  #1  
Old 03-15-06, 05:53 PM
Member
Thread Starter
Join Date: Feb 2006
Posts: 10
Received 0 Votes on 0 Posts
Gypcrete

Since gypcrete is poured over a wood subfloor, do I really need a vapor barrier if I'm above grade on the second floor? Also, can thinset be used over gypcrete. I had some float work done by a professional to get my floor flat and he used a thinset mortar compound. He said it would be fine. Any disagreements?
 
Sponsored Links
  #2  
Old 03-15-06, 08:55 PM
Member
Join Date: Jan 2006
Posts: 75
Received 0 Votes on 0 Posts
no disagreements with using a patching compound. Yes, your floor is above grade, with wood all around and under, so a vapour barrier is optional to a point.

During a complaint inspection, you may encounter a problem with not using a vapour barrier as the specs on most laminates state that on top of concrete you must use one, and an inexperienced inspector may take you to task and reject the complaint on those grounds.

For my money, an extra 0.10 cents per foot is worth the cost versus the possible rejection down the road.
 
  #3  
Old 03-16-06, 08:48 PM
Join Date: Nov 2000
Location: Austin, TX
Posts: 5,074
Received 0 Votes on 0 Posts
Originally Posted by Rotty
no disagreements with using a patching compound. Yes, your floor is above grade, with wood all around and under, so a vapour barrier is optional to a point.

I disagree 100% with this.


It is a known fact that portland and gypsum don't mix. The portland will pop the soft gypsum surface. ARDEX GS-4 is the recommended underlayment.


Gypsum and lightweight concrete are pumped with 4 times the moisture in order to pump it, then concrete. That is why it cracks and turns to powder over the years as it dehydrates. Yes, it all has moisture vapor emissions, or it would turn back into powder, even faster.

Use a moisture barrier! Being it is a floating floor, you should be OK, as sand is self flattening, too.
 
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: