Can you layer subfloor?

First layer must be dry prior to laying the second layer. Place a layer of 15-lb felt on top of the subflooring prior to installing second layer. Adhesives should not be used to fasten the two layers together. Install second layer on top of the first layer inside of the wall studs.

What goes on top of subflooring?





Underlayment: Some types of flooring can be installed directly on top of the subfloor, such as vinyl flooring. Other types need a middle layer, called underlayment, such as laminate,carpet and tile.

Should I fill gaps in subfloor?

Fill Plywood Subfloor Gaps



You don’t have any control over a subfloor that you just uncovered by removing carpeting or some other flooring, however, and it’s important to fill existing gaps to guarantee thermal and moisture isolation and protect your new flooring.

How do you fill a large gap in a subfloor?

How to fix large gaps in the subfloor

  1. Move the floorboards. Some people will tell you to stack the floorboards as close to each other as possible when you lay down your subfloor layer. …
  2. Use fillers. …
  3. Use strips of wood or other materials. …
  4. Replace floorboards.


What do you put between layers of subfloor?





Adhesive will help you here, as the subfloor plywood will have voids in spots that will not hold a fastener. I use the term “underlayment” to mean a layer above the subfloor, but not the finished floor. In your case, you need the underlayment to prevent deflection along the edges of the subfloor between the joists.

Do you need two layers of subfloor?

That’s the usual approach. Almost no one puts down double-thick subfloor in residential applications (for cost and handling reasons), and both layers need to be fastened to joists. Only thin underlayment can be fastened just to the subfloor.

What goes on top bathroom subfloor?

Generally, this only refers to a layer of plywood but in the case of bathrooms, it includes an underlayment of concrete backerboard as well. Concrete backerboard helps protect the plywood from water damage and helps prevent bending that leads to cracked tiles and uneven flooring.

Is subfloor considered structural?

The purpose of a subfloor is that it offers a structurally sound flat surface to hold up the underlayment and finish floor. The best material for a subfloor is typically plywood for its strength.

Which is the term used for the top layer of the floor finish?



Screed is usually applied on top of the concrete slab and is most commonly used as a finishing layer on internal floors or to level the floor prior to final floor coverings carpet, tiles, natural stone, linoleum, wood flooring, resin coatings etc.

How do you fill a low spot subfloor?

In order to repair low spots in wood or concrete subfloor, you’ll need either a floor patch product or floor leveler specifically made for underlayment. Floor levels are cement-based products that either come premixed or as a dry substance that you mix with water.

How do you fix a high spot in a subfloor?

Paper Shims and Plywood Strips



Minor high spots for hardwood and laminate floor installations are easily fixed with tar paper shims. The most basic method is to take a piece of tar paper, fold it in half and then push that underneath the flooring material being installed over the subfloor.

How wide a gap can you caulk?



A single bead of caulk can fill gaps up to 1/4 inch. If the gap is slightly larger than this, fill it with a bead of caulk deeper into the gap, but not flush with the surface. Wait until the caulk is completely cured before coming back to put a surface bead on.

Can you put plywood on top of subfloor?

Install a layer of at least ½” or preferably 5/8” ply over the existing planks. This is particularly important if your old sub floor has lumps and bumps in it. If you don’t respect this thickness of ply, then you’re highly likely to see rises and falls in your new flooring.

Can you put subfloor over subfloor?

One of the benefits of removing the old flooring is it allows you the chance to fix any loose subflooring or squeaks by re-securing the main subfloor to the floor joists prior to installing the new flooring. With all that being said though the answer is YES you can install New Wood Flooring over the old.

Do you need vapor barrier between subfloor layers?

Vapor Barrier Blocks All Moisture Issues



It just depends on how much moisture it emits. Concrete is porous in nature and will soak up any moisture that is in the ground and show up on the top of your concrete. So we recommend vapor barrier for all flooring installation that have a concrete subfloor.

Do you need a moisture barrier on wood subfloor?



Do I need a vapor barrier for hardwood floors?” The answer is YES! Moisture can destroy hardwood flooring. It causes cupping, warping, and even mildew if not treated. You must install a moisture barrier to protect your flooring from water wicking up from below.

How do you install a moisture barrier on a subfloor?

Quote from the video:
Quote from Youtube video: Side we're going to go ahead lay this out make sure it's right where we want it and then fold it back peel our tape off. And seal it to this plastic strip that they have coming from this other piece.

How do you stop moisture subfloor?

What steps should you take to prevent subfloor moisture?

  1. Take proper measurements before, during, and after installation of the moisture level. …
  2. Add a flooring underlayment with a vapor retarder barrier, also known as a moisture barrier. …
  3. Make sure that your contractors don’t penetrate the vapor barrier.


Why does my subfloor keep rotting?



Subfloor damage is typically caused by overexposure to moisture. This could be from excessive humidity, a leak in your plumbing or a crack in your home’s exterior.

What causes moisture in subfloor?

Understanding The Causes:



So, air conditioning your home in hot, humid weather creates a strong water vapor drive from outside to inside. Cold air conditioning can also cool the subfloor below the outdoor dew point temperature, which causes moisture in the air to condense on the cool subfloor.