vapor barrier and flooring on slab concrete

cbrowers · 01-31-2012, 02:29 PM

I am getting ready to put flooring in on a concrete slab floor. I am unsure if the previous owners installed the vabor barrier under the concrete or not. During the summer the concrete sweats in some spots due to humidity I assume, because it only happens on real hot days, not when it rains. My question is which vapor barrier should I install before laying down any flooring. The concrete is very cold in the winter too. Also, due to this, should I limit my options on the type of flooring I put down??

dlwilson88 · 02-01-2012, 02:23 PM

Check out this website about concrete sealing, curing and coating
http://m.concretenetwork.com/fix-con...t-choices.html
Hope this helps answer some of your questions

RenoStruct · 02-02-2012, 09:41 PM

This sounds like a condensation issue, not a vapor drive issue.

What type of flooring do you have panned? You should really use an insulating underlayment prior to flooring (as well as a barrier). There are plenty of options out there for wood or for tile. Which would you like to hear suggestions for?

gabish · 02-02-2012, 10:19 PM

Hire a pro to do a rh test. They drill a hole in the concrete to find out its relative humidity. That would be s start. If its high (80-90%) I would ask them to do a calcium test. This test measures the actual moisture leaving the surface.

dlwilson88 · 02-02-2012, 10:37 PM

I also am facing similar issues... except I just cut a 4' x 4' section of concrete out of my basement floor ( it was a section directly under the bottom landing which I decided to take out and found out that they never finished the concrete) they didn't even float it even with the rest of the floor, it looked like someone dumped a load of concrete there and just walked away..
Anyway after removing the uneven section I found out that they never put down any black plastic nor did they use any fencing, no re-bar nothing... and if that's not bad enough the pour was only 2"!! Although I haven't had any water problems, (just bought the house in February of 2011) we haven't had any long hard rain to speak of.
I'm wanting to put down real hard wood flooring, would you recommend 4 mil black plastic and 30lbs felt or what? And what about 1" or even 2" blue Dow Styrofoam Utilityfit Insulation board. ( I'm using the 2" on all the walls against the block than my 2x framing with r-15 than 1/2" green moisture board...
Any and all input would be very helpful...
Thanks

Hemlocks · 02-03-2012, 10:20 AM

We are installing engineered floating bamboo over an at-grade concrete slab with radiant heat. We know 6 ml plastic is recommended as a moisture barrier, but our dealer suggested Quiet Walk, which is a cushioned pad with plastic adhered to one side. I am not confident this is enough to block moisture - any suggestions? the house is on a lake in Vermont, so it gets cold in winter and pretty humid in summer. Concrete is about 7 years old.

01-31-2012, 02:29 PM	#1
cbrowers Newbie Join Date: Jan 2012 Posts: 1	vapor barrier and flooring on slab concrete I am getting ready to put flooring in on a concrete slab floor. I am unsure if the previous owners installed the vabor barrier under the concrete or not. During the summer the concrete sweats in some spots due to humidity I assume, because it only happens on real hot days, not when it rains. My question is which vapor barrier should I install before laying down any flooring. The concrete is very cold in the winter too. Also, due to this, should I limit my options on the type of flooring I put down??

02-01-2012, 02:23 PM	#2
dlwilson88 Newbie Join Date: Jan 2012 Location: Southwest, Virginia Posts: 13	vapor barrier and flooring on slab concrete Check out this website about concrete sealing, curing and coating http://m.concretenetwork.com/fix-con...t-choices.html Hope this helps answer some of your questions

02-02-2012, 09:41 PM	#3
RenoStruct Member Join Date: Jan 2012 Location: Ohio Posts: 34	vapor barrier and flooring on slab concrete This sounds like a condensation issue, not a vapor drive issue. What type of flooring do you have panned? You should really use an insulating underlayment prior to flooring (as well as a barrier). There are plenty of options out there for wood or for tile. Which would you like to hear suggestions for?

02-02-2012, 10:19 PM	#4
gabish Newbie Join Date: Feb 2012 Posts: 2	vapor barrier and flooring on slab concrete Hire a pro to do a rh test. They drill a hole in the concrete to find out its relative humidity. That would be s start. If its high (80-90%) I would ask them to do a calcium test. This test measures the actual moisture leaving the surface.

02-02-2012, 10:37 PM	#5
dlwilson88 Newbie Join Date: Jan 2012 Location: Southwest, Virginia Posts: 13	vapor barrier and flooring on slab concrete I also am facing similar issues... except I just cut a 4' x 4' section of concrete out of my basement floor ( it was a section directly under the bottom landing which I decided to take out and found out that they never finished the concrete) they didn't even float it even with the rest of the floor, it looked like someone dumped a load of concrete there and just walked away.. Anyway after removing the uneven section I found out that they never put down any black plastic nor did they use any fencing, no re-bar nothing... and if that's not bad enough the pour was only 2"!! Although I haven't had any water problems, (just bought the house in February of 2011) we haven't had any long hard rain to speak of. I'm wanting to put down real hard wood flooring, would you recommend 4 mil black plastic and 30lbs felt or what? And what about 1" or even 2" blue Dow Styrofoam Utilityfit Insulation board. ( I'm using the 2" on all the walls against the block than my 2x framing with r-15 than 1/2" green moisture board... Any and all input would be very helpful... Thanks

vapor barrier and flooring on slab concrete