best glue for concrete

[herd]

I am going to raise the floor level of a concrete deck on an addon that I am doing to my den. I intend to use 2x4's flat and then upright. I want to glue the flat 2x4's as well as fasten with 3/8 tapcons and some ramsets. What is the best construction adhesives to use on this, would Liquid Nails HD do the job or is there a better adhesive?

If it was wood-to-wood, I wouldn't hesitate to use Liquid Nails but am not familar with its ability to bond to concrete. I know Loctite has a HD construction adhesive that is rated high but I have no exp with it. tks.

 

[Shirleyshusband]

I've done exactly what you are doing several times and never had a callback/problem.

 

[JB4310]

Since it's not a critical application almost anything you put in there will suffice. But since nothing permanently bonds to concrete, it's more of a gap filler/cushion, to stop creaking, you're trying to achieve.

Liquid nails can get hard and brittle, I would recommend something more flexi, even a silicone caulk, not the adhesion of the LN, but your screws are going to be doing all the holding anyway.

Even that stuff they put on the top of foundations before they put the sills on, it's a rolled foam insulation.

Use the LN from there up, but IMO maybe not the best for the bottom.

JB.

 

[/pine]

Did you consider roofing cement?
it does not cure nearly as fast as more profound adhesives but it will eventually cure as a cement and it bonds well to to both treated or non-treated wood and concrete.

 

[radioman]

Did you consider roofing cement?
it does not cure nearly as fast as more profound adhesives but it will eventually cure as a cement and it bonds well to to both treated or non-treated wood and concrete.

good point. most treated stuff fresh from the store is pretty wet, hard to glue with. I assume you going to use treated boards on concrete ?

 

[herd]

I did not think about roofing tar/cement, but I will now as what you say makes alot of sense. I will be using treated wood, "yellow wood" in fact, it is not usually as wet as regular treated and supposedly not as corrosive to your fasteners.

tks for the idea

 

[JB4310]

I don't think roof cement is a good idea, and this is coming from someone who has made a career out of using roof cement, do alot of roof repair with nothing more than a trowel and a pail of "tar".

It will stick to the concrete as good as anything else, but it never really "sets up" like a caulk or adhesive, so you will not get any adhesive strength, more like a contact hold. Eventually it will get hard, but as designed, that ability to stay soft is what's needed for roof repair, preventing re-cracking where the material bridges over cracks and holes in the roof surface.

For that same reason it would not make a good cushion like a caulk or foam, since it isn't designed to set cure like adhesives and caulk, it just skins over. During initial install it would just squash out as you tightened the fasteners and would not retain any cushioning characteristic, and if it got warm enough in there it could settle and level out, making it not even a good gap filler.

Again, since it's not a critical app I doubt you would notice the difference between any way you chose to do it. But the roof cement might be the messiest, I would think a good quality soft foam insulation might be best, not one that you spray out of a can but something on a roll.

Google Image Result for http://www.homedepot.ca/wcsstore/HomeDepotCanada/images/catalog/17039.193689_4.jpg

I have seen problems with putting wood floors over slabs, where moisture and humidity were an issue.
A plastic vapor barrier over the top of the slab would probably help.

JB.

 

[forgeblast]

you can check for moisture coming out of the cement by taping a plastic bag on the floor and leaving it there over night. then you can check to see if its dry or wet.

 

[6sunset6]

I would think moisture coming out would vary with the season.
I would put down a vapor barrier. If you put it under the 2 x 4 that pretty much eliminates glue. You could put it over which would be ok .
I think roof cement would never stop out gassing and you would smell it forever inside. Urethane caulk sticks to masondry and wood and although not a structural adhesive , not to bad. Comes in tubes and a little hard to find . Home D does not have it Lowes does. Little stiff in the tube .

 

[TheRegMan]

PL is the absolute best adhesive I have ever used. I used liquid nails until I was putting some marble tiles up and it would not hold the tiles vertically. I went back to Lowes and decided to try the PL. That is all I'll use for anything anymore.

 

[bugstruck]

PL or LN construction adhesive should work. If the slab were vapor barriered beneath the concrete it's more likely to hold but tapcons or an angled case hard nail anchor (can't remember the name but I think Rawl made it). As for the vapor barrier I could make an equal or better case (depends the actual conditions) that letting it breath is better. Breathing is breathing though, so getting some air migration is required but may not be desired. Much easier if the sleeper depths are more along the size of typical joists. As for the PL on the marble. NEVER. That is an oil based product that wicks through natural stone. Some stones hide the migration to surface. Most don't. The only other hope is that it cures out before it bridges the thickness of the stone and LN would stand a better chance of that. How do I know? Short answer. Did the same thing as a youngster on a vanity top. Pulled it and trashed it.

 

[nickel plate]

Concrete is going to wick ground moisture. I don't like the idea of using petroleum based adhesives for concrete to wood. The PL product is a petroleum base subfloor adhesive-wood to wood. Find and use a water based adhesive. Your fasteners alone will hold everything in place and the adhesive will fill any voids and act as a buffer.

 

[radman1]

I have used PL. Love the stuff. Different formulas based on what you want to use it for. I have glued wood to cement. Later tried to remove the wood. The wood will crack, splinter and still stay stuck to the cement. I still like to use a few Tapcons or something else, should the glue fail. Lots of construction guys just use the adhesive but maybe I am a little too conservative.

IMHO, I would not use tar, silicone or caulk. Does not have the strength or strong adhesion.

 

[JB4310]

I still think the adhesive strength in this application is a non issue, adhesives are used in flooring to prevent creaking due to loose fit up and seasonal shrinking of the wood components and when fasteners start to loosen over time.

In this case I would put a high quality vapor barrier down first, caulk or seal the barrier around the perimeter, Then lay the sleepers down, maybe on that rolled sill foam insulation, if the floor is very uneven then a couple layers and fasten the wood down solid. instead of just screws, some heavier lags would really keep it in place for the long hall.
The kind of lags that you just drill through the wood the same size as the lag, then drill the concrete through the same hole and install the lag through the wood, so your not trying to line up pre drilled wood with installed lags.Powers Fasteners Or at least something like this http://www.powers.com/product_7204SD.html it would be better than regular Tapcons.

Glue the components from there up.

Ventilation would be nice, but might not be feasible, it would have to be able to allow air movement in each of the individual bays.

JB.

 

[herd]

tks JB, and everyone. good solid advice here. The fastener that I am using is a RamSet Redhead," extremely strong and heavy duty. I referred to it as a "Tapcon" but it is much more heavier duty, galvanied, and very sismilar to the Power Fasteners you referred to. YOu drill your hole 1/16'' less than the fastener's diameter, and rachet it in. The last turn is very tight and snug, in fact, I strain a bit on that last turn.

 

[yooperdave]

What exactly is 'PL'?

I know Urethane with adhere like grim death.

Yooper Dave

 

[Pops15]

What exactly is 'PL'?

I know Urethane with adhere like grim death.

Yooper Dave

Don't remember what it stands for but PL is a brand name of construction adhesive that is similar to Liquid Nails. I use it for drywall, subfloors and underlayment.

 

[GE222]

You could use a 2-part epoxy. Make sure the floor is clean and oil free.

The mechanical fasteners should be enough along with liquid nails.

 

[SpringHollow]

Definitely test for vapor as recommended. A good vapor barrier is usually critical.

Ken

 

[Danno1]

Don't remember what it stands for but PL is a brand name of construction adhesive that is similar to Liquid Nails. I use it for drywall, subfloors and underlayment.

PL400. It's another type of uethane. You'll find it anywhere on the same shelf as LNs. I also think it's better than LNs.


.