Vinyl siding is incredibly popular mainly because of its affordability, durability, and ease of maintenance. The fact that it is water-resistant is a quality that adds to its appeal. The question is: if vinyl is water-resistant, is there really any need of installing a house wrap behind your vinyl siding.

You need a house wrap behind vinyl siding simply because while the vinyl itself is water-resistant, even a perfect vinyl installation tends to have seams, tiny gaps, and lines. Moisture, especially wind-propelled moisture, can therefore get through the siding installation and into your home. Some states make it mandatory to install house wrap behind vinyl siding.

Having a house wrap behind the vinyl siding will ensure that your home has an extra line of defense against moisture. It can thus go a long way towards preventing mold growth, and water damage.

How do house wraps work?

House wraps contain very tiny perforations. These perforations are usually so small that water molecules cannot pass through. Therefore, even when wind-driven moisture manages to get past your vinyl sidings, it won’t have a chance of getting into your home because the house wrap will form a moisture-resistant barrier.

However, the holes in the house wrap are typically large enough to allow moisture in vapor form to pass through. As a result, if there is any moisture in a home, it can easily escape through the house wrap. This is something that allows the house wrap to act as an effective shield against extreme weather elements without creating a mold or water problem inside the home.

Why do houses need wrapping?

The following are the main reasons why houses need wrapping.

Reduce mold problems

House wraps are designed to work as moisture barriers. And they are very good at it.
For homes that have a mold problem, wrapping the home is the first step towards getting rid of the problem. This is because mold loves moisture, and removing the source of water that is sustaining its survival and development is an effective way of discouraging an infestation.

Prevent moisture damage

Moisture seepage through vinyl sidings is a common cause of property damage in homes. It encourages rotting. And it typically leads to ugly streaks that spoil the aesthetic appeal of the home. Therefore, wrapping a home is sometimes necessary to stem moisture damage.

Improve the home's energy efficiency

House wraps are made from material that is poor at conducting heat. Therefore, wrapping your home is an easy way of adding a little bit more insulation to your home. This will play a role in making it more energy-efficient.

Furthermore, wrapped houses don’t have a pronounced air leak problem. This is because the wrapper reduces the ease with which air can escape. This means that during the cold season, the rate at which your home loses heat will be lower. And this will go a long way towards reducing the amount of energy that is used to keep your home comfortable.

Keep home more comfortable year-round

When cold air drafts infiltration a home, they cause a sudden drop in temperature. This usually makes the home very uncomfortable.

Even though standard house wraps are not designed to act as wind barriers, they normally provide an added obstacle that will reduce the amount of air that eventually gets into the home. Furthermore, there are wraps that have been enhanced to act as effective wind barriers, and installing these wraps will definitely improve the comfort of your home all year round.

Retain or improve a home's value

If a home is located in an area with extreme weather conditions, wrapping it will make it more attractive to potential buyers. The moisture protection that wrapping provides, in addition to the potential energy savings that come with such an installation, will make it get picked up faster. It may even end up commanding a higher price.

Even if one isn’t planning on listing the home in the market, wrapping it will prevent moisture damage to the home’s insulation, sheathing, and walls. This will help to at least preserve the home’s value and to avoid unnecessary repairs.

Comply with building codes and regulations

In some local jurisdictions, wrapping a home is not only recommended, but also required. A home that is located in an area that mandates that builders wrap houses needs to be wrapped in order to ensure that it complies with the law.

Is installing house wrap behind vinyl difficult?

No, installing a house wrap behind vinyl is not difficult. It is a straightforward process that does not require any special skills or procedures. As a result, it will likely form a very small part of the overall vinyl installation costs. The only thing that you should keep in mind is to install the wrap as per the manufacturer’s instructions and using the nails or fasteners that are recommended by them.

How to know if your house needs wrapping?

Your house needs wrapping if:

  • The building codes in your area make it a requirement
  • You experience occasional wind drafts
  • You have a mold problem that keeps coming back
  • You live in an area that experiences strong winds, heavy rain, flooding and storms
  • Your energy bills are unreasonably high

How house wrap affects ventilation?

Since house wraps are made of lightweight material that is designed to let air and water vapor out of a home, when it is properly installed, it doesn’t affect a home’s ventilation. It only has an effect on water molecules that try to infiltrate the home.

However, poor installation often results in the material lowering a home’s ventilation. A poorly installed wrap can stifle air movement, lead to an unnecessary increase in a home’s humidity, and lead to moisture problems.

This is why it is always advisable to leave the installation of house wraps to expert home wrapping contractors.

Connectivity between house wrapping and mold and moisture problems been properly installed

A house wrap that has been properly installed allows air and water vapor to pass through without a problem. Therefore, it has little to no chance of causing a mold or moisture problem. In fact, if anything, it helps to keep these problems at bay by preventing moisture infiltration from outside sources.

However, if a house wrap is improperly installed, it can be a major cause of mold infestation and moisture problems. This is because an improperly installed house wrap will cause poor airflow in a home. It will also act as a condensation surface where moisture gathers. The combination of these two things will encourage mold growth in vinyl sidings and even in the home. It will also lead to rotting and other moisture problems.


While you can replace siding without replacing your house wrap, it is generally recommended that you do. This is because, after the first installation, the house wrap usually develops perforations during the installation of the old siding. The added puncturing that it will incur due to the new siding installation can prove to be too much for it to create an effective moisture barrier for your home.

Foam board insulation is the best underlayment for vinyl siding because it increases a home’s energy efficiency, improves the home’s soundproofing, and even increases the home’s value.

Yes, water can get behind vinyl siding through the seams and gaps that are typically created during the installation process.

No, you don’t need a foam board under vinyl siding. You only need to install the foam board if you want to increase the insulation of your home.

House wraps are generally breathable. This is so as to ensure that it can allow water vapor from inside the home to escape. And so while putting two layers of house wrap on is not catastrophic, it can compromise the ability of the house wrap to avoid compromising the airflow in a home. Therefore, unless the manufacturer recommends it, you shouldn’t put two layers of house wrap on.

No, you shouldn’t use plastic for house wrap. This is because plastic is not breathable and using it will simply cause moisture and mold problems in your home.

The bottom of a house wrap is usually sealed at the bottom by attaching it to the home’s sheathing by using either tape or caulking.

If you need help installing a house wrap, you should use It offers a free service that quickly matches you with the top-voted local expert vinyl siding installers.

Using the website, you can get 3 estimates fast by real certified experts in your area in just 2 minutes. Here is how it works.

  1. You scroll to the top of the page and enter your Zip code.
  2. Answer questions about your house wrapping needs
  3. Your details will be forwarded to three local experts.
  4. You will then receive a price estimate for the job and some friendly advice.

IMPORTANT: There is no obligation to hire. This is a free tool and service to be used at your pleasure.

Timothy Munene
Author: Timothy Munene - Timothy is a freelance writer and an online entrepreneur.