| Author |
Message |
Colin Gilboy
Senior Member
Username: colin
Post Number: 384
Registered: 09-2005
| | Posted on Friday, October 17, 2014 - 02:47 pm: |    |
Posted by Jim Sciarrino (Unregistered Guest) on Friday, October 17, 2014 - 02:23 pm:
[I am cross-posting this into products as I do not expect to see any responses from the Conspectus TechTips area, plus I added a few typo corrections. Colin]
I have a terrazzo floor original from 1969 so I doubt if it is the epoxy variety. From 1999 - 2013, it was covered with wall to wall carpet/pad. Carpet/pad was removed Nov. 2013 & no moisture was seen or ever a problem. Laminate flooring (with vapor pad) was then installed by pros.
By July 2014 (after heavy rain & high humidity), laminate edge buckling was seen & floor was removed; lots of moisture mostly on top of the terrazzo (under vapor pad) was then seen although some moisture was on top of vapor pad. Moisture damaged laminate.
If (?) no vapor barrier was installed under terrazzo in 1969, could water travel up tosurface of terrazzo (and/or be trapped or condense under laminate vapor pad)?? Inspectors found no cause (plumbing, roof, etc.) of water entry.
Thanks.
Colin Gilboy
Publisher, 4specs.com
435.200.5775 - Utah
800.369.8008 |
Scott Piper
Senior Member
Username: spiper
Post Number: 9
Registered: 08-2014
| | Posted on Friday, October 17, 2014 - 04:02 pm: | |
It is difficult to tell where the moisture may be coming from based upon a verbal description but it does appear as though it is traveling up through the concrete slab and terrazzo floor as you suspect. The best way to tell for sure is to have a Relative Humidity test done by an experienced flooring contractor. The test involves drilling some holes in the existing slabs, inserting a test cap, waiting about 72 hours and then coming back and testing the RH levels in the holes.
I am not sure what the protocol is for RH tests in terrazzo over concrete slabs which is probably the condition you have so that should be reviewed with the company doing the test. You typically want to get to the midpoint of the concrete slab but I am not sure how the terrazzo may change this process.
If it was my floor (and the terrazzo was in decent shape) I would grind it, refinish it and not have to worry about flooring in this area for the rest of my life. |
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick
Post Number: 1601
Registered: 03-2002
| | Posted on Friday, October 17, 2014 - 04:16 pm: | |
Moisture can easily travel through traditional terrazzo and evaporate from the surface without being noticeable. Carpet and pad are quite vapor permeable, and water vapor has probably been moving through this slab and terrazzo since the day it was installed. I'm assuming the "vapor pad" has low permeability, so condensation will form underneath it. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 831
Registered: 12-2006
| | Posted on Friday, October 17, 2014 - 04:56 pm: | |
I agree with Scott as to the terrazzo vs. other floor finishes.
Cast-in-place concrete terrazzo is a concrete product. It will allow water vapor transmission.
As to the moisture, you will always get water vapor migration through slab-on-grade if there is no vapor retarder below. We don't know if this is a bonded terrazzo or a sand-bed terrazzo. With two years of moisture build-up, a sand-bed terrazzo could now be a blotter for all that moisture that was trapped.
What are you looking at doing? At this point I'm not sure how to dry out your substrate without tearing it out and putting a surface applied vapor retarder on top of the concrete slab. I would not put the surface applied vapor retarder on top of the terrazzo.
It sounds like the owner may want to start thinking about the beauty of terrazzo as a finished floor. |
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