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Discussion Starter · #1 ·
Hi.
I'm a GC, not a flooring expert. Client found a hardwood specialist he likes with a good price on the flooring he likes. I'd like to ask you about a couple of things the contractor intends to do because I don't know enough:

Installation will be engineered, unfinished Brazillian cherry glued directly to concrete slab. On the stairs, he will use a product called "New Stair" that he says allows him to convert prefab stairs to oak for staining.

1. I asked about a vapor barrier. The contractor says he has a special glue that handles that, and use of an additional paint-on type barrier would negatively affect the glue down.

2. Is the "new stair" product for prefab stairs (meaning not site built) a good product?

3. Contractor says prefiinished flooring tends to fade so he doesn't use it. Only uses unfinished wood that he finshes on site.

Does it all sound right to you? Thanks for any advice.
 

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Pompass Ass
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Whenever we do a glue down engineered floor on a slab on grade we use MVP as a moisture barrier, no matter what the mositure tests say and then use Bosticks best glue.

Not familiar with the stair product.

It seems to me that prefinished flooring would be more resistant to fading as in a factory they have better control over the finishing process.

A wood floor that is installed sanded and finished onsite if done correctly looks better than a prefinished job IMO.
 

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You should be able to go right over the slab as long as it is dry and clean if you are using a good poly glue like bostiks.I always glue down my unfinished wood and let it sit for 10 days or more before sanding and finishing to allow the glue to acclimate with the wood to minimize exspansion and contraction issues...If job is below grade...your on your own!!..Good luck..Iv'e never heard of the stair product either..
 

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Discussion Starter · #4 ·
Thanks for your responses. I have since learned that the installer plans to use Mapei 980, which he believes is similar to Bostik's Best. According to the Mapei website a vapor barrier is only needed if the slab fails a moisture test. I don't know that the installer has or plans to do a moisture test. I wonder if anyone really ever does that?

Here's the info on the stair product -- it's a good product from what I can see: http://www.nustair.com/installation.aspx
 

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Pompass Ass
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Thanks for your responses. I have since learned that the installer plans to use Mapei 980, which he believes is similar to Bostik's Best. According to the Mapei website a vapor barrier is only needed if the slab fails a moisture test. I don't know that the installer has or plans to do a moisture test. I wonder if anyone really ever does that?

Here's the info on the stair product -- it's a good product from what I can see: http://www.nustair.com/installation.aspx
You should put a moisture barrier down, no matter what a moisture test says.

It is cheap insurance.
 

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Mapai is ok and cheaper, not great. Bostiks Best is great. ( try getting it off your hands!)

Dont let him put that floor in until he test the moisture content of the slab and the wood your putting in.

For the few extra dollars a moisture barrier is smart insurance no matter the result.

I have been using Dependable's Cut Down as a moisture retarder. You apply a few coats of it, with a roller, in opposite directions and it gives you a nice clean hard surface to glue to.
 

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He has to test the moisture content of the slab and the wood.There are different test options for that-chemical or mechanical-.Slab must be 28 days or older.Unless the house sitting clay bed and have moisture traces all over,in and out,you will not need Bostik MVP,test first to see the moisture level on slab.
For the stairs treads and risers,he has to use a stair jig no matter what brand/type he is planning to use.Stair Jig looks like this.http://www.amazon.com/Wheaton-Tools-PL200-Stair-Wizard/dp/B0000224Q2/ref=sr_1_4?ie=UTF8&s=hi&qid=1255815477&sr=8-4
I did not notice prefinished fades more than unfinished all these years,Brazilian cherry will darken and get deep red within couple of months and stop darkening.
There are Brazilian Cherry solid (laminated real wood)stair treads,risers in the market,which will match with flooring,fading it from oak (by staining)is not acceptable for my clients,but they are mine,depends on customer.I usually finish them in my shop and then install on site.
But every flooring guy has his own way.:laughing:
 

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i did a big job this year we tested the slab, no sealer required. floor cupped as it was poorly made (bamboo). i just replaced all the floors at my cost as my suppiler said the floor failed due to the slab not being sealed.

to date i have spent 125k replacing floors and in legal fees against my suppiler.

if i win against the supplier then i will get my money back if they dont file for bankruptcy.

all jobs now get a sealer even if the slab is 100yrs old.
 

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There's a floor contractor around my area that installs 1/2" plywood on the slab. After the plywood he installs felt paper and then glues and nails the wood floor. The plywood is glued and nailed to the slab. Has anyone seen this method done.
 

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The plywood in itself will not deal with the moisture . I am not a fan of nailing any wood to a concrete floor. If you rolled a moisture retarder - it can be comprimised by the nails. Same to be said about a poly barrier.

Its a step that brings up other issues like clearance and doorway transition issues.


I know some guys like to nail when they can because its easier to make a tight floor as you go. But for my time and money gluing wood to a properly checked and prepared slab is better than layering wood for the sake of nailing.
 

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There's a floor contractor around my area that installs 1/2" plywood on the slab. After the plywood he installs felt paper and then glues and nails the wood floor. The plywood is glued and nailed to the slab. Has anyone seen this method done.
That is because he doesn't know what he is doing, his method makes no sense.

If you want to do a glue down, you don't put down a wood sub floor.


When you install a wood sub floor over top of a slab on grade, you install the felt paper, then 3/4" T&G plywood, then nail the floor to the wood subfloor.
 

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Pompass Ass
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i did a big job this year we tested the slab, no sealer required. floor cupped as it was poorly made (bamboo). i just replaced all the floors at my cost as my suppiler said the floor failed due to the slab not being sealed.

to date i have spent 125k replacing floors and in legal fees against my suppiler.

if i win against the supplier then i will get my money back if they dont file for bankruptcy.

all jobs now get a sealer even if the slab is 100yrs old.
That is why I always use MVP, no matter what the moisture test says.
 

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Thanks for your responses. I have since learned that the installer plans to use Mapei 980, which he believes is similar to Bostik's Best. According to the Mapei website a vapor barrier is only needed if the slab fails a moisture test. I don't know that the installer has or plans to do a moisture test. I wonder if anyone really ever does that?

Here's the info on the stair product -- it's a good product from what I can see: http://www.nustair.com/installation.aspx


This guy sure wished his installer had done a moisture test.
 

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Installer is 90% right...

Your installer sounds like he knows what he is doing, but has some personal preferences coloring his opinions. May not be wrong, just opionated. First, probably does need to do a moisture test(s) if there is any doubt, but I assume he may have already done so.

Most glues for hardwood on concrete contain a moisture barrier as part of the formula. Assuming what he uses is like this there is no need to use a sealer.

I'm leary of "sealers." In many cases a sealer must be REMOVED before gluing down - otherwise it prevents proper adhesion and the glue may peel up like paint. (I've seen paint peel up on a sealed concrete floor, luckily before we glued down wood on another part of the suite.)

I've never seen anyone use an engineered UNFINISHED wood, though I suppose there is no reason not to. My question is how thick is the wear layer? Many engineered woods have a very thin wear layer and if you sand very deeply you are up **** creek. I disagree that a sand & stain floor gives a finish superior to prefinished. The opposite is true if all other factors are anywhere close to comparable. Same wood, but stain is applied under controlled factory conditions, typically 7 to 10 layers of poly plus aluminum oxide instead of just 3 layers of poly done on-site.

Biggest reason people say they like a S&S floor is the square edges instead of beveled edge on prefinished. Is your engineered unfinished floor square-edge or beveled? Installers tend to treat unfinished wood rough, counting on the sanding to make up for "boo boos." So a lot of installers don't like prefinished because they have to actually take care while installing.

Prefinished floors will not fade any faster than S/S. The reverse is probably true, but any floor will change color - look at any of them where part has had a lot of direct sunlight, covered by an area rug, etc. The quality of the wood and finish regardless of prefinished or S/S probably has more impact.

One of my vendors has added the stair tread things you describe and I'm thinking about adding a display. Haven't installed any, but everything looks good about them. Essentially is cheaper/faster/easier to install over particle board or pine treads than tearing out the staircase, having a finish carpenter install new treads, then sanding and finishing.

As far as nailing plywood over concrete so you can nail down a solid hardwood floor, I think doing so is goofy. I know people who have done it and claim it came out okay, but I have my doubts and think most will develop problems of some kind down the road. Just goofy - it's usually someone who doesn't know jack about anything except 3/4' solid trying to get around his limitations. But that's just my opinion...

Good luck!
 

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Pompass Ass
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bwalley you are right. Do you perfer to install the subfloor over the slab or do you install a sealer and then the wood?
If it is an engineered glue down, we use MVP moisture barried no matter what the moisture test says, the we glue the floor down with Bosticks best.

If we are doing a nail down, it can be either solid or engineered, we install either MVP or felt paper then nail down 3/4" T&G plywood, then nail down the flooring, if we aer worried about sqeking floors we will install a layer of felt on top of the plywood, then install the floor.
 

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i did a big job this year we tested the slab, no sealer required. floor cupped as it was poorly made (bamboo). i just replaced all the floors at my cost as my suppiler said the floor failed due to the slab not being sealed.

What makes you think it was poorly made? Who told you you didn't need a moisture barrier with bamboo?

Concrete has the ability to be cooler than dew point temperature, so if you slab tested within specifications, and you documented it with pictures and a job log, what does the slab test now? What changed, beside your wallet getting lighter.

Bamboo always gets a moisture barrier, even if the slab test OK, as dew point can make it cup.
 
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