Are you planning to replace your cladding and have decided to give your house a wrap? And do you want to know which wrap is the best—Typar or Tyvek? You’ve come to the right place, for we have researched this question and have the answer for you.
Here are some basic statistics of these two home wraps that you might like to consider:
- Typar has resistance to surfactants, while Tyvek does not.
- Tyvek is thicker than Typar by up to 20 times, adding to its durability.
- Typar has almost four times tear resistance than Tyvek.
- Tyvek’s protection against air and water intrusion is in its entire thickness, while Typar only provides single-layer protection.
Learn more about these two home wraps in the succeeding sections, including what properties are important to consider when choosing a home wrap. Read on to learn all about it!
What is a home wrap?
A home wrap or a house wrap is a WRB or a weather-resistant barrier you wrap around your home. The goal of your house wrap is to prevent water and air from getting through the walls.
Keep in mind that a house wrap is not a plastic sheet. While it prevents water and air from getting in, it should let water vapor go out.
Various daily activities inside your house produce water vapor, and this mixes with the air. Taking a warm shower and cooking food are some of the activities that add water vapor to the air inside your house.
Too much water vapor in the air negatively affects the comfort of your home. Your HVAC will also need to work harder to get rid of excess moisture in the air to cool your home.
What does it have to do with your house wrap?
A house wrap must be breathable so that water vapor can escape through it. Thus, an ideal house wrap should not let air and liquid water in but will let water vapor out.
Benefits Of A House Wrap
By preventing moisture and air from getting through your walls, a house wrap also prevents the growth of mold by cutting off its source of moisture. Protecting your house from moisture also protects it from damage that comes from the accumulation of water and moisture like wood rot.
Preventing air and water from getting into your house also minimizes the energy that you consume for heating and cooling. This makes your HVAC system more efficient. It also reduces maintenance costs of your HVAC system because it does not work extra hard to cool or warm your home.
Preventing water from getting through your walls prevents your insulation from getting wet. This protects your insulation from damage.
How to select the right house wrap for your home?
There are dozens of house wraps on the market (in addition to Typar and Tyvek) today, so it can be hard to choose the right house wrap for your home. Fortunately, the ICC-ES or the International Code Council Evaluation Service conducts tests and evaluations for different building materials and products, including house wraps. The ICC-ES evaluate house wraps for compliance with standards and provides observations based on their tests.
Here are the characteristics that a good house wrap should have:
Resistance To Water
This property allows a house wrap to perform its basic function of preventing liquid water from getting through. The ICC-ES performs three tests on house wraps to determine their ability to keep water out.
Both Tyvek and Typar are resistant to water. However, Tyvek has greater protection because its entire thickness prevents water and air from passing through.
The construction site of a house or building is not a place for gentle handling. Construction materials—including house wraps—should be durable enough to survive regular handling during construction.
There are a few subcategories under this property that we will talk about in greater detail below.
Tear resistance is an important durability criterion. It prevents the house wrap from getting torn during installation. This minimizes loss from material damage during installation.
Tear resistance prevents tears that lead to water and air leaks that compromise the protection of a house wrap.
Typar and Tyvek are tear-resistant. However, as mentioned above, Typar is four times as tear-resistant as Tyvek.
House wraps lose their ability to repel water when exposed to UV rays. They also lose a lot of their tensile strength from UV exposure.
This is where UV resistance becomes important.
Due to the nature of the materials used for manufacturing house wraps, house wraps can never be completely immune from the effects of UV rays. This is why the UV resistance or UV rating of house wraps is measured in months. This is the amount of time that the house wrap can have UV exposure before degradation starts.
When installing a house wrap, UV protection can be seen as the time frame that the cladding should be installed to protect the house wrap from UV exposure.
The ICC-ES recommends UV protection of at least one month for house wraps.
Both Typar and Tyvek have UV resistance. Typar has an industry-high UV resistance of 6 months, while Tyvek has UV resistance of 4 months.
Vapor permeability is the measure of how much vapor the house wrap allows to pass through it. This is a property that allows underlying materials like the walls to dry if they get wet. The unit of measure for this property is perm.
A higher perm rating means that the house wrap allows more vapor to pass through. However, more is not always better when it comes to house wraps. A higher vapor permeability can start to reduce the ability of a house wrap to repel liquid water unless it has a high level of resistance to water to offset this.
If the perm rating is too low, water vapor that comes from inside the house will not be able to escape fast enough and can lead to condensation within the walls of the house.
The sweet spot for house wraps is between 10 to 20 perms. A material must have a minimum of 5 perms to be considered as a house wrap and not a vapor retarder.
Typar’s vapor permeability is 7 perms. Tyvek, on the other hand, has a perm rating of 56.
A house wrap also prevents the flow of air across its barrier. Air leaks are a passageway for losing warm air during winter or cold air during summer.
Both Typar and Tyvek pass the air resistance test.
The ability to drain water is widely accepted as the most effective method of preventing water damage in houses. Drainage prevents the accumulation of water. Wet surfaces with no water accumulation will dry faster than areas with water accumulation.
Thus, it is important for house wraps to have the ability to drain water. Drainage helps house wraps do their job more effectively because wet areas will dry faster.
A gap between the cladding and the house wrap will drain rainwater before it has the chance to penetrate the house wrap and reach the wall.
House wraps help achieve this by creating a drainage plane on their surface. The drainage plane creates a gap after the installation of the cladding over the house wrap. The gap serves as the drainage for rainwater in case it penetrates the cladding.
Tyvek has a drainage plane on its surface, while Typar does not.
Resistance To Surfactants
One of the concepts that house wraps use is the effect of surface tension on absorbability. All liquids have this property, but the surface tension of water is important because it is what hits houses in the form of rain.
Have you ever seen a drop of water on a leaf that looks almost spherical? What allows water to look this way is surface tension.
Surface tension is the property of liquids to seemingly have an elastic membrane holding the liquid inside. A high enough surface tension will prevent a liquid from penetrating certain materials. Water’s natural surface tension, for example, prevents it from immediately penetrating certain surfaces like house wraps.
Surfactants are substances that reduce the surface tension of liquids. If a surfactant mixes with rainwater, rainwater’s surface tension will drop and give it a better chance of penetrating a house wrap.
Another feature of some house wraps is the ability to repel surfactants on their surface to prevent rainwater from mixing with them. While this is a nice feature, a high enough water resistance property can still repel the combination of water and surfactant.
Typar Or Tyvek
These two brands have their respective properties that you should consider for your project.
If you will be working on your house wrap project only during weekends, you will need a house wrap with a high UV rating like Typar. If your location is known for wind-driven rain, then you will need a house wrap with a drainage plane to drain water that gets through the cladding like Tyvek.
These are just examples of situations where you match the property of the house wrap with the conditions in your environment and construction area.
Tyvek Homewrap Sheet is available on Amazon through this link.
Instead of picking a house wrap based on industry opinion on which one is the best, pick a house wrap that has the properties that match the needs of your house.
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