Glue assist installation

[AlexR]

Hello all!
I’m going to install 3-1/4” hardwood oak floor (over waferboard subfloor) and to minimise any squeaking I want to do full cover glueing with Bona 851R in addition to nailing. I know that I’m overdoing it, but really want to minimise potential squeaking in the years to come. My question is: is it okay to walk on the floor while I’m installing it? On the one hand, the glue can be used in addition to nailing. On the other hand, it asks not to walk on the floor within one day of installation. I’m confused. I would really appreciate any advice

 

[Commercial Floor Rep]

What's the overall thickness of your subfloor and what's the joist spacing?

 

[AlexR]

What's the overall thickness of your subfloor and what's the joist spacing?

Thank you for your quick reply! Thickness of the subfloor is 2cm and space between joists is 35cm. And I also checked: the subfloor is actually waferboard, not OSB.

 

[C.J.]

Wafer board as in particle board?

 

[Commercial Floor Rep]

I don't think wafer board is an acceptable substrate for any wood installation (floating, glued, stapled or a combination). That's going to need to be replaced before you begin. If possible, pictures would help us understand exactly what you have.

You typically want a minimum of 1" or 2.5cm total thickness for the subfloor. A good practice is to install a layer of 5/8" (1.6cm) plywood and then a second layer of 3/8" (.95cm) with the second layer (the 3/8" layer) installed perpendicular to the first. This will help to stiffen the subfloor and minimize deflection (vertical movement) of the floor. Minimizing vertical movement is key in eliminating potential squeaks. OSB can be used instead of plywood, but it generally does not hold fasteners well, which can lend itself to squeaking.

Most squeaks in wood floors come from fasteners, so eliminating fasteners from the install and just gluing the flooring is a huge step in removing potential squeaking. Often the sound you're hearing is the sound of the wood moving up and down against the fastener. Use a good quality urethane-based adhesive such as Bostik's Best or a similar product and just glue the flooring using the manufacturers recommended trowel notching. There can be other causes of squeaks such as movement causing the milled joints to rub, or other structural issues leading to movement in the support system of the floor. But again, minimizing movement as much as possible is the key to squeaks.

Typical glue assisted installation doesn't involve full spreading the adhesive. It generally requires the use of a urethane wood adhesive or construction adhesive in a tube form with a bead of the adhesive being applied serpentine fashion to the back of the board and then the board is fastened into place. It's also important that you're using the appropriate fastener and the appropriate length of fastener. The fastener should be a length that penetrates the maximum depth in the subfloor without passing through the underside of the subfloor. If it goes through you lose a large part of the holding power of the fastener.

Wish you well with your project!

 

[C.J.]

Jim is shaking a stick at you right now, CFR

Changing directions with subfloor or underlayment is a no no. Both plywood and carbon fiber have cross layers of material and they are both pretty strong materials. The difference is the multiple layers are all glued together resulting in a single stronger layer of material.

When you install a second layer of plywood, you aren’t glueing them together, you’re just nailing them. In fact Jim would jump all over you for even suggesting you glue a second layer of underlayment to the first. And you sure as heck better not mix your patch on the underlayment either. You gotta keep your plywood, OSB or whatever running perpendicular to the joists to retain the strength axis of plywood. Otherwise you’re adding thickness to your floor system without gaining the strength that the additional layer of underlayment adds. you might have 1” of subfloor but only have the sag resistance of 5/8” and that ain’t much.

Offset your side seams by a foot or 2 and run it perpendicular to the joists. All of it.