I intend to use this for my glue down...Supposedly it uses "spacers" that appear to be some kind of grit/particles that assure the boards maintain a uniform height above the concrete for proper drying. The coverage is only 'up to' 120 sq ft/3.5 gallon which makes it very pricey.....

It IS very expensive (more than 2x the price of Roberts) compared to other adhesives available locally (HD has an adhesive, Roberts, for around $80/4gallon/200 sq ft.) that does not provide a vapor barrier.


Any opinions on this stuff, or the Roberts? Is Bostik overkill or is Roberts just as good?

P.S. No moisture problems with the slab.....

It's hard to keep track of the names of those adhesives Bostik's is putting out. The Single App http://bostikdiytube.com/product/single ... r-membrane has the rubber in it and as far as I know was only available from LL. The Single App is from Lowes and does not have the rubber in it last time I used it.

I used both on a stranded Bamboo gluedown. I actually liked the Lowes product better than the LL one with rubber particles in it. It is more like the Roberts in consistency. That Single App is a totally different adhesive and it spreads like chocolate mousse, kinda frothy without the froth. Hard to explain.




And what tests did you perform on the concrete?

Moisture tests- I have a moisture meter that I bought long ago from Northern Tools that I use for lumber and it works equally well on concrete but I also....

I did the plastic/tape down tests. I bought a kit. I've done these before on other projects (concrete borders and patio slab) and have confidence in them as I've always seen mositure, or staining under the plastic when moisture was present.

I checked the slab in 6 different areas. No stains, discoloration or moisture under the plastic. Doesn't mean that in the future it can't happen though.......we have a high water table here in Florida.

BTW, you mentioned that it's hard to tell what's in Bostik's 'Single App" and you're right. There's absolutely no product number or model number on the can whatsover. If it's there it's well hidden. I surfed the web to try and identify the product sold by LOWES and came up with same link you show above.
Now I'm wondering if this product is what's shown in the video or not.....

But I digress....is this expensive product even necessary or can I simply get away with the ROBERTS at HD for $80/4 gallon?

You might and then you might not. It gets complicated. You need to follow the mans installation requirements to a T for any type of warranty assurance. Then you better have it documented to a T, pictures, test results, either CaCl (ASTM F-1869 ) or ASTM F- 2170 at least, sometimes I do both with ph test as well. I don't know of any adhesive company they allows a concrete meter or the ole plastic mat test.

As much as I like to give jason a hard time his mat test video is so funny. Gotta love it.

http://www.youtube.com/watch?v=uAIjz9Io ... e=youtu.be

Yeah, I know what you mean...It's time to commit to something. I'm no dummy when it comes to 'stuff' that's mechanical and my intuition tells me that I'm probably going over the top on adhesive.

BTW, I've seen that video before and don't agree with his conclusions. If the area under the plastic is BONE DRY, then you're good to go. Anything else requires further testing....He seems to imply that people are interpreting the results after having found droplets, or moisture under the plastic. I don't think anyone ever advocated coming to such conclusions. It's simply a Go/NO-Go test. NO-GO+ more tests......

I just sanded the entire slab where the builder's contractor had used some glue to hold down the carpet padding. The glue was/is solidly imbedded in the concrete.

I suspect that the adhesive I use, regardless of whether it's ROBERT's from HD or the BOSTIK from LOWES is going to adhere to the slab, likely for as long as I would care to have it do so....

I'm not inexperienced with engineered flooring and regardless of the finish warranty, 50y-100y, experience tells me that likely I'll be ripping it up 10~13 years from now. Styles change and H/W flooring gets to look pretty 'ratty' after 10 years or so IMO, regardless of the finish warranty. Scratches, dents, and dings, water damage (inevitible regardless of how careful you are) will neccesitate replacement.

When I do so I'll probaly thank myself that I DIDN't scarify the surface because at that time in the future I'd have a real 'project' on my hands to get the stuff up and get the slab clean again....

There's qualitative....plastic mat and concrete meter, then there quantitative measurements....ASTM F-1869 and ASTM F-2170. Qualitative just don't cut the musturd unless you know the slab is sound with a vapor retarder under it. Otherwise that floor could just come up all by itself. Flip the coin.

Well, as you know in another thread I did relinquish and finally went ahead and used a scarifier to abrade the surface of the floor.....

I'll reiterate though that I am somewhat concerned about having to sometime in the future removing this floor but I guess I'm committed now so no point worrying about that. The glue's likely to be well imbedded into the concrete as a result of the scarification and impossible to remove in the future....

The mositure test, using visquine and tape, is very adequate and has been around for years and years, well before portable moisture meters were even available.
I'll reiterate that the test results are a go/No-Go result and I've never heard anyone trying to interpret the results beyond that.
I've used this test many times to determine when to paint pool/patio/deck concrete in the past and it's always been adequate.

What ever turns your crank branded. But just because the slab is not wet with the plastic mat test but yet has droplets of water on the plastic has a significant meaning just as the wet looking crete does.

So how goes the test anyhow, somewhere between lost and bewildered?

Lol, no the result that show moisture, droplets, or stains under the plastic simply says STOP- don't go FORWARD!
Do Nothing until investigating and measuring further...Like I said, Go/No-Go....- no further interpretation beyond that......

'Go' is bone dry after a couple of days.....

'No-Go'- go get some tests done or buy yourself a meter.....Then decide what to do; wait (new concrete) for it to cure, seal it (topically for painting) or use a vapor barrier (as in flooring) or fix more serious problems if they exist (high water table, foundation drainage, etc.)...

It's just that this test's been around for a long, long time....

Problem is you can be tricked just by a dewpoint issue.