Laminate subfloor moisture testing often overlooked yet most critical when installing laminate flooring. Concrete slab and wood subfloor both have moisture limits. Failure to skip laminate subfloor moisture testing often results in laminate floor failures.
Failure to Perform Laminate Subfloor Moisture Testing
Buckling, cupping, squeaking, raised edges are but a few of the problems that result from ones failure to perform subfloor moisture testing. Installed over a substrate that has excessive moisture content the laminate will likely fail.
When a floor fails because a flooring installer or homeowner decided that the concrete looked dry enough and skipped the laminate subfloor moisture testing, who’s fault is that? The installer is going to blame the homeowner and the homeowner the installer. It certainly isn’t the fault of the laminate flooring manufacturer. After all, the manufacturer warned you in their installation instructions that the floor needed to be tested.
Moisture testing doesn’t only apply to concrete slabs, it also applies to wood subfloors. Yes, even wood can have an excessively high moisture content. You skip the testing and often within days of installation you hear “snap, crackle and pop” or you think you are walking on a trampoline.
Laminate Subfloor Moisture Testing Requirements
Most laminate flooring manufactures have their own requirements for subfloor moisture testing. Some of these manufacturers may refer you to the installation standards of NALFA, the North American Laminate Flooring Association. If the laminate manufacturer does not offer moisture testing standards, refer you to NALFA or other industry standards, my best advice is to stay away from that product.
Moisture testing standards follow for several NALFA member companies:
Wood Laminate Subfloor Moisture Standards
-Kronotex less that 14% on wood subfloors.
-Shaw 12% maximum on wood using a wood pin probe meter.
-Mannington, Columbia, Mohawk, Quickstep, Unilin each state that subfloor moisture content may not exceed 12%. Since these companies do not specify the type of meter used, either a pin or noninvasive is acceptable under their subfloor moisture testing standards.
-TOYLYS states that subfloor moisture content may not exceed 10%.
As you can see by the moisture standards of these manufacturers, not all requirements are the same. Don’t risk the failure of your new laminate floor and don’t void your warranty by failing to follow the standards of your flooring manufacturer.
Concrete Laminate Subfloor Moisture Standards
Shaw, Pergo, Kronotex, Mannington, TORLYS, Columbia, Mohawk, Quickstep, Unilin all require Calcium Chloride testing performed to ASTM Standards. The vapor emission standard for each of these companies is a vapor emissions reading of less than 5-lbs per 24 hours, per 1000 square feet.
How to Perform a Calcium Chloride Test
Terry Weinheimer | Kevin Weinheimer
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I had an emissions reading of approximately 6.5lbs and would like to use quick step flooring. Is that amount reduced if I use a vapor barrier? And if no, what are my options?
Joe
The Quick Step installation instructions state that the concrete must be less than 5 lbs/24 hour per 1000sqft (Calcium chloride method ASTM 1869). If your concrete is 6.5 lbs the moisture level is too high for their product. A vapor barrier will not reduce the moisture in the concrete it only slows the passage of the moisture. If this is fairly new concrete you may need to allow it to dry longer or consider a product that is allowed over 6.5 lbs.
Best to you,
Terry
Elongated damage or blister-like surface as though air is under the surface, mostly on the tongue side and end ocassional joints…and 2′-3′ and less from ends of boards. It appears also as a “tap block” problem but tap blocks were not uses when installing the T&G product. What could this be?
The floor does not have expansion seam joints at doorways or in runs 25′ and more. Side joint at walls appears OK where tested, but gap at entire walls was not checked for. The condition described started small but is now considered pervasive.
The cause for replacing the laminate floor (with laminate) is because the dishwasher leaked and the kitchen floor and all floor-mounted cabinets had to be replaced because of water damage and a lack of products available to match old cabinets.
Jeff
There are a number of possible causes for the problems you describe. If the laminate flooring was not properly acclimated prior to installation this could be the cause. Kicking a floor together can cause this type of damage. Uneven expansion from high moisture, lock-in, lack of transitions can cause problems similar to what you describe. Spraying cleaners directly on the floor instead of the applicator or using steam can cause similar problems. I would suggest you go to the NALFA.com website or NICFI.Org and hire a qualified inspector to check it out. If you are in our Oregon and Washington service areas you may want to give us a call.