QA

Quick Answer: How To Do Subfloor

What are the requirements for subflooring?

The minimum thickness of plywood for subflooring is about 5/8 inch. Since it does not hold fasteners as well as plywood, OSB must be a little thicker, or at least 23/32 inch. There are several factors that determine what subfloor thickness is optimal for added benefits like insulation.

What do you put under plywood subfloor?

Plywood is only one type of underlayment. Other common types include cementboard or tile backer (used under ceramic or stone tile), foam underlayment (used under laminate and engineered wood “floating” floors), and rosin paper (used under solid hardwood flooring).

What goes on top of subfloor?

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.

Which side of subfloor goes up?

When installing sub-flooring, you’ll want the rough side facing up as well for traction when working. This is especially true when you have OSB that has been treated with a sealant or moisture barrier.

What thickness of subfloor should I use?

The recommended thickness of the plywood subfloor is governed by the spacing of the joists. Some experts suggest that 15/32-inch plywood should be standard if the underlying floor joists are spaced 16 inches apart or less, but slightly thicker 3/4-inch plywood should be used for joists spaced further apart.

Do you need tongue and groove for subfloor?

For subflooring, you use tongue and groove plywood. The tongue and groove are only along the 8 foot edges. On the four foot edges, your seams will fall on joist tops, so no need for tongue and groove.

Is it better to use OSB or plywood for subfloor?

The National Tile Contractors Association and the Resilient Floor Covering Institute both recommend plywood for subflooring and underlayment, because it doesn’t have the risk of swollen edges that OSB does. Plywood also has a slight advantage in stiffness, which means that subflooring panels need not be quite as thick.

What can I use for a subfloor?

Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.

How do you prepare a plywood subfloor?

Clean the Subfloor Step 1: Remove the Existing Flooring. Pull up the current floor. Step 2: Measure the Pieces. Check that your moisture barrier, underlayment plywood and plank fit under your door casing and door. Step 3: Clean the Subfloor. Step 4: Inspect the Moisture Level. Step 5: Secure Loose Boards.

Can you put hardwood flooring over subfloor?

3/4″ Thick Solid Wood Flooring can be installed directly over 3/4″ thick OSB subfloor. It is standard practice to install the hardwood floors at a 90 degree angle across the floor joists to stabilize and strengthen the whole floor structure.

Do you nail or screw subfloor?

Ideally, nail down your subfloor using corrosion-resistant nails that will securely hold it in place and last a long time. Screws are a great alternative that you can easily remove, but they are not as sturdy. Screws are superior in terms of reducing floor squeaks, but the installation is slower.

Which way do you lay plywood subfloor?

Install plywood underlayment smooth side up. To avoid damage to the surface, install underlayment immediately before laying the finish flooring.

What is the difference between subfloor and underlayment?

The subfloor is the bottom most structure of the floor. It provides a flat and stable surface and supports the actual floor. Underlayment is different from the subfloor in that it rests between the subfloor and the actual floor.

Should subfloor have gaps?

To avoid buckling, subfloor panels should be spaced with a 1/8-inch gap at all edges and ends to provide room for naturally occurring expansion. Tongue-and-groove edges on many premium floor panels, such as Weyerhaeuser’s Edge Gold® OSB panels, are designed to self-gap.

Do I 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.

Does subfloor go under walls?

Wall and Floor Basics Subfloor: The subfloor is nailed to the top of the joist. Often 19/32-inch to 1 1/8-inch thick plywood or OSB, the subfloor might run continuously across the joist, or two sections of subfloor may meet on a joist. Bottom Wall Plate: The bottom wall plate is the bottom-most part of the wall.

Can subfloor be installed upside down?

Upside-down Installation: Panels may be sanded on one or both sides. In all cases, the detailed panel trademark stamp should be installed downward so they can be examined during inspections. Installing some panels with the trademark side up may result in a slightly uneven surface.

Should I glue and screw subfloor?

The answer: Glue. Although using a subfloor adhesive (or subfloor glue) is not required by code, it is a standard practice that can help prevent floor squeaks by reducing the chance for movement at the panel-to-joist connection. A quality subfloor adhesive will also increase the overall stiffness of the floor.

What screws to use for a subfloor?

Most construction experts use 3-inch steel screws for plywood subfloors. To find out which length of screw you’ll need, you first have to know how thick the flooring is. You’ll want the screw to go about an inch past the plywood into the joist or underlying layer beneath it.