Is a House Wrap Necessary Before Siding Installation? (2024)

FAQs

Is a House Wrap Necessary Before Siding Installation? ›

Generally, if you're installing vinyl, aluminum or wood siding, you will likely need to use a house wrap. Wood siding, for instance, benefits from house wraps because it usually has several seams with overlapping boards.

While not entirely necessary, it's quite important to have a house wrap underneath the siding on your home, especially if your siding is made of vinyl or something like it. While vinyl siding can protect your home from air and moisture, it does not create a vacuum seal on your home.

A house wrap protects from water damage.

And we haven't yet considered the fact that the siding panels themselves could have cracks and other imperfections that would let wind and water through. The house wrap's role as an additional line of defense is essential for the most assurance against weather damage.

Regardless of what material you're using for siding, none of them are impervious to the penetration of moisture or air. Whilst it is not a mandatory requirement for homes to have housewrap, it is highly advised by all construction professionals.

There are contractors who may suggest that you can forego using house wraps when you're replacing your siding. Still, most installers will say that it's a vital part of your siding system.

Siding industry pros say that while the house wrap may be a moisture barrier, it's not 100% invulnerable against water. This means that if you make the mistake of leaving it exposed to water for too long, water can eventually get through it and reduce its effectiveness or even render it useless in the long run.

Thermal insulation products – either in the form of insulation boards acting as sheathing, or flexible foil products (including bubble foils) – might be considered. Few will provide both moisture resistance and vapour permeability.

While the Tyvek house wrap is designed to withstand exposure to the elements for up to nine months during construction, once the wrap is fully installed and covered with an exterior cladding, it can last indefinitely.

Usually, older homes don't have a house wrap because it wasn't used at that time. But there are some that do; usually, these homes have been retrofitted, but the cost to do so and the difficulty of the job will vary widely based on its size, age, the type of construction and the type of siding.

Can I use plastic sheeting as house wrap? ›

Recommended Materials for Vapor Barriers

Most home builders recommend at least 6–mil thickness. Plastic sheeting provides an effective air and moisture barrier, but the construction process can easily damage it. Plastic sheeting is not recommended for brick houses.

Plastic cap nails or plastic cap staples are highly recommended for fastening the building wrap. Simply put, the use of caps seals holes made by the penetration of the fasteners.

Tyvek^®HomeWrap^® exhibited nearly four times the vapor permeability of perforated house wrap, which can only allow vapor to pass through punched holes. The superior vapor permeability of Tyvek^® HomeWrap^® correlates to decreased wall cavity drying times, and a reduced potential for mold and wood damage.

There is no logical reason not to have house wrap under vinyl siding, and many authorities strongly agree that it should be viewed as mandatory, even if your local building codes don't necessarily require it.

Installing a house wrap is usually considered in siding installation projects. It offers several benefits like moisture protection, added insulation and improved energy efficiency. House wraps also come in different types designed to meet specific needs.

Generally speaking, removing the old siding prior to re-siding your house is good practice, good business and a wise consumer service, even though this removal practice is unpopular with both the siding contractors and customers paying the additional costs.

Even the United States Department of Energy (DOE) agrees that “when new siding is to be installed, it is a good idea to consider adding insulation under new siding.”

If you choose to install housewrap with rigid foam, generally, it should go under the insulation, not around it.

Yes, House Wrap Does Come First!

Often, those installing foam board insulation ask, “Do I put house wrap on first or second?” Whether you're installing James Hardie board siding or not, house wrap is always applied first. The experts place the material in the proper orientation to achieve maximum insulation.