Do I need a vapor barrier under my wood floor?

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.

Does subfloor need vapor barrier?

Vapor Barrier Within a Crawl Space

Besides having a vapor barrier on top of the subfloor, it may be necessary to have it under the subfloor when the subfloor is over a crawl space.

Do I need a moisture barrier under laminate on wood subfloor?

No matter which underlayment you choose, if you are installing on a moisture prone subfloor or concrete subfloor, you really need a moisture barrier underlayment. Protect your laminate flooring from moisture for years to come by installing moisture barrier underlayment.

What is the recommended underlayment for hardwood flooring?

What Underlayment is Best for Wood? When installing hardwood or engineered wood flooring, the best underlay options are cork and foam. However, foam does have more give than cork so, while it is the more popular option, we recommend cork. Cork has less give, making it less likely to flex underneath your planks.

Should you put a vapor barrier between subfloor and underlayment?

It is rolled out between the actual laminate flooring planks and the subfloor. Very often, particularly in a below-grade installation on a concrete basement floor, a vapor barrier is recommended in addition to the underlayment. That vapor barrier would go between the subfloor and the underlayment.

Cold Climate Building Techniques and Concepts: Vapor retarder

Does plywood act as a vapor barrier?

1) Exterior plywood sheathing is a moderately effective vapor retarder with a perm rating of less than 1.0 as long is it is kept dry and the relative humidity is low. When plywood is wet or relative humidity is high, its permeance will range from above 1 to as high as 10.

Is vapor barrier necessary?

A vapour barrier is an important component in building construction. Its purpose is to help prevent water vapour from reaching building walls, ceilings, attics, crawlspaces or roofs, where it can condense and cause building materials to rot or grow mould.

Should I put felt paper under hardwood flooring?

Felt paper is installed under hardwood flooring to provide an extra layer of moisture protection and also to dampen sound. You will need to install it under your wood floors if a padding is not already attached to the hardwood planks. Many models of hardwood planks have dampening foam already attached.

Can you install hardwood floor over plywood?

Engineered or Solid Wood Flooring that is less than 1/2" thick can be installed over a plywood subfloor.

How do I protect my subfloor from moisture?

Should I put tar paper under subfloor?

Foam, felt and rubber are the best choices for laminate underlayment. Do not select tar paper to go under laminate or vinyl flooring, because the odor can penetrate the air and the fumes can be toxic, according to Uooz.

Do hardwood floors need to breathe?

Hardwood floors naturally expand and contract as the relative humidity fluctuates from one season to another. That is why installers must leave space between each wood plank and the wall; this allows the wood to “breathe”.

Where does the vapor barrier go on a floor?

In the typical crawl space with a dirt floor, a 6-mil plastic vapor barrier is used to prevent moisture from the soil from coming up into the crawl space area. That vapor barrier is laid directly on the dirt, and the seams are overlapped at least 12 inches. The other vapor barrier is created with your floor insulation.

Where should vapor barrier be installed?

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates. In existing spaces, oil-based paints or vapor-barrier latex paints offer an effective moisture barrier.

What direction do I lay hardwood flooring?

The most common way to lay hardwood flooring is by aligning the planks parallel to the longest wall. Apart from a few exceptions like sagging joists, this is the preferred direction to lay wood floors because it aesthetically provides the best result.

What is the difference between subfloor and underlayment?

Basically, subfloors are a structural part of your home that provide strength and rigidity to your home's flooring. Underlays, on the other hand, protect your floor covering from moisture, help soundproof your floor, and offer cushioning and comfort underfoot. You can think of your floor like a sandwich cookie.

Can OSB be used as subfloor?

Most local codes allow OSB to be used for subflooring. It's always best to check with your local permitting office before using OSB for your subfloor. One advantage that OSB has over plywood is its larger formatting. For plywood, 8-foot and 10-foot long sheets of plywood are standard.

What is black paper under hardwood floor?

black felt paper is rolled out over the wood subfloor prior to installing the new floor. This hardwood felt paper is necessary to greatly reduce the chance of any moisture coming up through the subfloor and will help protect the new hardwood flooring.

Is rosin paper necessary under hardwood floor?

As mentioned above, the National Wood Flooring Association (NWFA) explicitly recommends not using rosin paper with hardwood flooring. The reason is that rosin paper does not function well as a moisture inhibitor.

Is it better to staple or nail hardwood flooring?

A staple will give a stronger, less-forgiving hold because of its two-pronged construction. Nails allow for a more natural expansion and contraction of the hardwood floorboards with fewer problems.

Can I use plastic sheeting as a vapor barrier?

Reinforced polyethylene plastic sheeting (poly) comes in a variety of thicknesses and strengths. A 6 mil thick poly is commonly used as a vapor barrier and offers short-term savings to the homeowner.

Do vapor barriers cause mold?

The Problem With Vapor Barriers

This can lead to significant moisture problems and mold; problems occur when walls get wet during construction or more often throughout the home's life.

Does drywall act as a vapor barrier?

The permeance of unpainted drywall is very high, generally between 20 and 90, so it's not a vapor retarder at all. Meanwhile, air leakage through a 1 square inch hole in a sheet of drywall allows 30 quarts of water vapor to pass through the drywall under the same conditions. A third of a quart versus 30 quarts.

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).