Is it Necessary to Have Housing Wrap Underneath Your Siding? (2024)

FAQs

Is it Necessary to Have Housing Wrap Underneath Your Siding? ›

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.

By installing a house wrap before your siding installation, you can reduce the likelihood of wood rot, mold growth and moisture infiltration in your home.

It is possible for moisture and air leaks to enter through these fine lines and seams, wreaking havoc behind the siding that you may not even notice until significant damage has already occurred. Despite the good qualities of vinyl, it does pay to have extra insurance in the form of house wrap.

Much goes into a wall beneath the home siding, including studs and framing, sheathing (OSB panels), underlayment, insulation, flashing, interior surface, trim, and paint.

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.”

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.

Whilst it is not a mandatory requirement for homes to have housewrap, it is highly advised by all construction professionals.

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.

It's necessary), but as your customers/owners face the rising costs of construction materials, you, as the builder/distributor, are likely to face pushback from owners who are looking for opportunities to cut costs. When faced with this question, in many cases, the answer is simple: it's required by the code.

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.

Should the bottom of house siding be sealed? ›

The bottom of siding boards should not be caulked.

Backerboard. Backerboard, also known as sheathing, is a structural layer beneath the siding panels. Sheathing is typically made of plywood, oriented strand board (OSB), or foam boards and is installed over the exterior framing of the house.

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.

There are two main reasons to use sheathing: structural and non-structural. Non-structural sheathing improves insulation from heat, cold, and sound. Structural sheathing improves the building's stability and keeps the wall from swaying or bending overtime. It also provides a base for the siding to be nailed into.

If you choose to install housewrap with rigid foam, generally, it should go under the insulation, not around it. However, you can rely on the advice of your contractor to make your final decision, since not every professional agrees on this order.

Extruded polystyrene (XPS) fanfold siding underlayment arguably provides the best performance in the industry. GreenGuard® offers several types of siding underlayments to suit a variety of needs and applications.

Furring or strapping must be applied to create an even base for siding.

While fiber cement siding is already waterproof, James Hardie recommends applying their nonwoven synthetic house wrap beneath your siding as that final line of defense if your siding should fail, and so do we.

Vinyl siding must never be applied directly to studs without sheathing. As an alternative, installation of specific types of drop-in contoured foam underlayments for various styles of vinyl siding are available.