Contractor Talk - Professional Construction and Remodeling Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
110 Posts
Discussion Starter #1
I wonder why so many people's immediate reaction to Hardwood on concrete is NEVER?

Many Hardwood manufacturers are Allowing and providing a warranty for glueing down to concrete under the right conditions.

I recently laid Bamboo over concrete and wonder if/why others would shy from this given the following conditions.

* Calcium Chloride test ='d 5Lbs per 24 Hrs
* ABOVE grade and proper drainage (gutters) and sloping grade outside.
* House at normal temp and humidity for many months prior to install.
* Bosticks MVP used as moisture barrier
* Bosticks best used as an adhesive.
* Floor flat per install specs.

I expect no problems with this floor under normal conditions.

I am just curious b/c all to often I see/hear people immediatly say engineered only; and often this is best - but some really want 'real wood'.

Would it not be better to respond to people that glue downs are not advised for novices but Hardwoods can be installed under the PROPER conditions?

Just wanting to start a conversation b/c I see alot of people shy away from hardwood when in fact they could have their original choice installed worry free?

I think MVP and Taylor's Lock down are great new products allowing more options for flooring. Loc-Down advertises their 'sealer' will protect wood from concrete with a vapor emmision of 12# per 24 hours.

Just wondering what others think.....
 

·
Registered
Joined
·
10,471 Posts
I suppose that the best argument is that wood and concrete expand and contract at different rates. Over time, the cyclic rate is going to cause failure.
I would feel comfortable installing it with the following provisions.
The concrete is fully sealed, minimum 2 coats of sealer.
The humidity in the house is fully controlled.
The flooring is ricked in the home for at least a week prior to install.
Any and all warrantees are void if the home is opened for ventilation, power loss for more than 10 hrs. and a few other things.
Some things just don't work together due to thier physical properties, wood on concrete is one example. I can elaborate further.
 

·
Custom Builder
Joined
·
4,406 Posts
I had a fella put down plastic over the concrete, running it up the walls behind the baseboard, then 1/4 foam board, then floating hardwood. This was way back around 90 or 91.

I wasn't real sure about the method but my installer insisted. It turned into a nice install and the floor didn't get real cold, and it was very cold outside a day or two after install.

My brother ran into the customer last year and they talked awhile, I guess all is well, If he had any sort of product failure I'm sure he would have told Joey.

Bob
 

·
Flooring Guru
Joined
·
2,794 Posts
I will only float hardwood over concrete.
as long as a moisture barrier is installed and a moisture test is done.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #5
Teetorbilt said:
I suppose that the best argument is that wood and concrete expand and contract at different rates. Over time, the cyclic rate is going to cause failure.
I would feel comfortable installing it with the following provisions.
The concrete is fully sealed, minimum 2 coats of sealer.
The humidity in the house is fully controlled.
The flooring is ricked in the home for at least a week prior to install.
Any and all warrantees are void if the home is opened for ventilation, power loss for more than 10 hrs. and a few other things.
Some things just don't work together due to thier physical properties, wood on concrete is one example. I can elaborate further.

I can understand and agree that concrete needs to be sealed if the MVE is unacceptable and should be sealed if the MVE of the concrete is low. I agree that the wood and house need to be acclimatized properly.

I am having trouble with concrete vs wood expansion:

1. All wood reacts differently to moisture and movement. OSB can expand much faster than most hardwoods; but it is acceptable now as an underlayment for nail down floors. I am no expert but I do not think concrete expands very much, far less than wood I am sure. Different wood species expand at different rates.

2. Concrete does settle like other foundations and I think that may be an issue ; but expansion of concrete does not make sense. Wood subfloors are very porous and can easily expand if moisture conditions in the crawl space are not kept right. It almost seems if you could keep a the MVE of a slab in check(with a sealer), it may even be a safer bet to install over a slab b/c the risk of a flood in the crawl space is non-existant.

3. It seems many different mediums are mixed with wood: vinyl windows, steel, sheet flooring and other things. Installed properly they all can coexist with wood. In Alaska many houses have metal roofs installed over OSB - i am sure the OSB and metal expand and contract at different rates but failures are limited.

I am just curious as to the reluctance of many to use new products and offer thier customers more options. I know in AZ and CA suburbs - cement slabs in new construction are the standard and many wood floors are being glued down sucessfully every day.
 

·
Registered
Joined
·
110 Posts
I am curious as to why? Do you not trust the new products such as Bosticks MVP and Taylor's Lockdown?
Not yet. Plus there are many variables I am not yet tuned to find for this kind of install.


I am just curious as to why most are still reluctant to entertain the idea - when new methods are being created. NWFA now states that OSB is an acceptable underlayment - but most are still unwilling to naildown over OSB.
Because if the floor fails, then NWFA will not pay for replacement. It is up to the manufacturers to decide what underlay they want used.

I guess I can understand not wanting to be the case that proves these new innovations wrong; but many are doing it just fine.
And it may soon come to pass that it will be more used and accepted. It's just not there yet.
We will see in 10 years what happens with Home Depot and Bruce and all their jobs.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #7
I understand that gluing to concrete using MVP and Lockdown is fairly new and could be seen as risky. But the industry is innovating and more install options are becoming available. I also understand that NWFA or other manufacturers will not warranty a total replacement if the adhesion fails due to moisture.

I completely agree that the manufacturers instructions trump's everything. I am finding more and more manufacturer's are including glueing over concrete if the conditions are acceptable and the right products are used.

With any install I document everything with photos and keep good records.

I think bamboo is a great option for glue down and many manufacturers of Bamboo will allow glue down. I have no trouble glueing down as long as the customer knows the risks and the conditions are perfect.

My main point is that I believe it is a disservice to tell people the only option over concrete is floating or installing a wood subfloor over a moisture barrier as I used to do. I also do not think a gluedown is for a Homeowner to try themselves.

Just some thoughts........
 

·
Flooring Guru
Joined
·
2,794 Posts
Wow,

For some reason, when I posted my reply, it posted under your name....wierd...

by the way...are you in AK?

I understand your points, and agree with it.
It should be more common. I just think there is just too much involved at this point in making sure all the variables are met.
I guess I just have not met a client who demanded it yet :)
 

·
Registered
Joined
·
110 Posts
Discussion Starter #9
Florcraft said:
Wow,

For some reason, when I posted my reply, it posted under your name....wierd...

by the way...are you in AK?

I understand your points, and agree with it.
It should be more common. I just think there is just too much involved at this point in making sure all the variables are met.
I guess I just have not met a client who demanded it yet :)
Yeh that was a wierd posting thing going on. I am in Homer, AK and do flooring and other trim work. Just moved there from Valdez and have lived in Anch. I learned the flooring trade in CA and sometimes go down and do some installs there for old clients. That is where the concrete comes in to play.

I recently had a client that really want HW on slab. First - I was on the old line 'can't be done, get engineered' Then I started researching and realized many floors could be done on slab in the right conditions. I think as time progresses this stuff will be proven OK.

If you ever spread Bosticks MVP - you'll be almost convinced it works just by it's consistancy alone. Years ago I used to treat concrete floors in industrial warehouses and the America West Arena in Phx - the chemicals we used then - the MVP looks alot like this chemical sludge and I am sure it will be proven to lower Moisture Vapor Emmisions. I guess time will tell; but I am convinced...
 

·
Flooring Guru
Joined
·
2,794 Posts
First off....

Homer Ak is my favorite place up here.
My wife and I love to stay in some B&B's up on the hill. I cannot get enough of that place.

As far as the hardwood on concrete goes, keep me posted will ya?
I know that we have some interesting humidity up here and so I usually vote for the most stable option.
I do not do alot of solid woods up here because of it.
But I would be interested in hearing how things are workin out for you.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #11
Homer is our favorite spot also, thats why we built our house there. It is especially nice after living in Valdez (which i believe is one of the nicest spots in AK -as long as you don't have to live there) We live up on the hill and back behind it by the 'ski tow line deal' Ohlson MT up with snow like hillside in ANCH.

Engineered is surely the most stable; but regular hardwood will work in most conditions as well. I just hear people getting directed to engineered all to often when they want HW, for false reasons. Humidity is a factor everywhere and is a concern; I do think we have more humidity that say Florida. I think we have the contrary (low indoor humidity) b/c of our longer heating season. Excessive shrinkage could be more of an issue, especially if the wood is not properly acclimatized at installation time.

These are all obstacles that can and are sucessfully dealt with all of the time. There are scores of wood installers in ANCH and AK installing wood everyday with no problems. I know that engineered is surely popular up here though.
 

·
Flooring Guru
Joined
·
2,794 Posts
Most reps will push the salespeople in selling engineered if it's in their line.
I think it's because of less call backs, but who knows.

Here comes the future......
 

·
Registered
Joined
·
9 Posts
If You Going To Use The Glue Down Method I Recomend A Sika Bond Sealer Followed By Sikabond Adhesive T55 T52or You Can Lay A Plyboard Underlay Then Secret Nail The Hardwood Floor Or Batten The Floor,followed By Secret Nail Ensure You Do A Humidity/moisture Testor You Could Use The Proflorr Method Of Batten Onto Saddles/insulation Then Floor.that Is A Expensive Method Though
 
1 - 13 of 13 Posts
Top