Now you see why I don't want Bob on this site!

[CC Solutions]

Stephen,
Condensation is not an issue for me. I do carry a infrared thermometer and a small $100 pocket temp/RH reader. If the building has the HVAC running (which is a requirement for installing flooring) the slab will not be at dew point.

But of course I do not install flooring, I prep floors and install MMS. In many cases the HVAC is not on, but I must NOT install when the slab temp is rising or within 5 degrees of dew point. It's really quite simple.

I realize you have installed for 35 years, but in reality the first 20 were much different. We had adhesives that could glue (what did that guy say?) shrimp boats to the ocean floor. A good friend and colleague of mine says we could have cattails growing and put the vinyl down with no trouble. The new adhesives require different parameters.

The good MMS systems are testing to ASTM E96, and we're not going to verify that in the field. I don't test after installing an MMS, it doesn't really matter because I know the system I use, and the manufacturer puts a 10 or 15 year full system warranty on the floor. If it ever fails, it's covered.

It is NOT the concrete person's responsibility to lower the RH or emissions. They have no control over how long the slab cures, how much water is in it, how thick it is, when the HAVC is turned on, nothing!

I believe it is the flooring contractor's responsibility to determine if the slab is ready for the type of flooring being installed. If it isn't, he should bounce it back to the GC and let him get it in condition. It's no different than if the building was at 20 below zero and the flooring contractor had to say he couldn't install until the heat is on and the conditions are right.

I have a unique perspective on this because I have been on every side of the situation and know what each contractor, architect, owner and GC is up against. I also sit at the resolution table and dissect where the process failed and who is responsible. I have also taken control of slabs from design to flooring to service that were successful and continue to be successful. Low RH and low MVER IS POSSIBLE if the slab is designed well and taken care of for the next 3 - 6 months.

The WORST thing I see happening is contractors who say "I've been doing this for 50 years and I never have a problem so this is all someone else's problem!!" If it's a flooring contractor he's right, it isn't his problem but he should be testing and may have to use different products he's not used to. The GC can't let rain flood his slab daily. The architect doesn't need a 6" slab on grade with 5500 psi, the concrete contractor can't burn the slab and then seal it with a silicate.

If you want a good dry slab the recipe starts with the design and ends with the flooring sub gluing to clean bare concrete. If you want to skip steps and do it the easy way, well a MMS can save the day. Like Leie said, you can ship UPS Ground and save the money, but if you want it Next Day Air, you have to pay the premium.