In construction and home building, ensuring the longevity and durability of a structure is paramount.
One of the essential elements that play a pivotal role in achieving this goal is house wrap.
But what exactly is a house wrap, and why is it crucial in modern construction?
A house wrap serves as a protective barrier designed to shield the internal structures of a home from external elements, predominantly moisture.
Think of it as a protective jacket for your house.
Moreover, beyond just moisture, house wraps also serve to enhance the thermal efficiency of a building, ensuring that the warmth stays in during the colder months and vice versa.
This dual function of protection and insulation makes house wraps an indispensable component in the construction realm.
Now, while house wraps are vital, like any other material, they come in different types and quality grades.
In this article, we'll dive deep into the debate between using roofing felt as a house wrap versus the traditional materials designed specifically for this purpose.
What are their pros and cons? How do they measure up against each other? Let's explore.
The Great Debate: Roofing Felt or House Wrap?
Roofing felt has long been the trusted companion of builders looking to safeguard roofs from water damage and environmental challenges.
But can this reliable material double up as a house wrap?
While it's true that roofing felt offers the possibility of serving as a house wrap, it might not be the most optimal choice.
Here's why: house wraps are crafted to balance breathability and water resistance. In contrast, with its focus on water resistance, roofing felt compromises the breathability quotient.
This small difference might not seem like a big deal, but it can cause big problems.
If the material doesn't breathe well, it can trap moisture, leading to mold.
Also, roofing felt isn't as strong as other house wraps, so it can be damaged more easily when put up.
So, should you use roofing felt as a house wrap?
It depends on what you need. If you live in a rainy area or worry about moisture, using a specific house wrap designed for that might be better.
Comparing Roofing Felt and House Wrap
Regarding protecting a building's exterior from moisture and air infiltration, two popular options are roofing felt and house wrap.
While both are designed to create a weather-resistant barrier (WRB), they differ significantly.
In this section, we'll compare roofing felt and house wrap regarding water resistance, durability, installation process, and cost.
Water Resistance
One of the most critical factors to consider when choosing a WRB is its ability to resist water infiltration.
Both roofing felt, and house wrap are designed to be water-resistant, but they differ in their permeability.
Roofing felt is typically less permeable than house wrap, which can trap moisture inside the wall cavity, leading to mold growth and other moisture-related problems.
On the other hand, house wrap is more permeable, allowing moisture to escape and preventing condensation from forming inside the wall cavity.
Also read: Can House Wrap Get Rained On? Debunking Weather-Related Myths
According to testing, roofing felt has a permeability rating of around 5 perms, while typical house wraps range from 10-35 perms. The higher the perm rating, the more breathable the material.
Durability
Another important factor to consider is the durability of the WRB.
Roofing felt is made from asphalt-saturated felt, which can deteriorate over time when exposed to UV rays and other environmental factors.
House wrap, on the other hand, is made from synthetic materials that are more resistant to UV rays and other environmental factors.
As a result, house wrap is generally more durable than roofing felt and can provide better long-term protection against moisture and air infiltration.
Industry tests show the average lifespan of roofing felt to be 10-15 years, while synthetic house wraps can last 20+ years.
Installation Process
The installation process for roofing felt, and house wrap is similar, but there are some differences.
Roofing felt is typically installed in overlapping layers, with each layer nailed or stapled to the sheathing.
House wrap is also installed in overlapping layers but is typically attached to the sheathing with special tape or staples.
Additionally, house wrap is easier to cut and work with than roofing felt, making the installation process faster and more straightforward.
Cost
Finally, cost is important when choosing between roofing felt and house wrap.
Roofing felt is generally less expensive than house wrap, making it a popular choice for budget-conscious builders.
However, the cost savings may be offset by the need for additional moisture management measures to prevent moisture-related problems.
House wrap, while more expensive, can provide better long-term protection against moisture and air infiltration, potentially saving money on repairs and maintenance in the long run.
Advantages of Using Roofing Felt as House Wrap
Roofing felt has been used as a house wrap for many years. Here are some of the advantages of using roofing felt as a house wrap:
1. Cost-Effective
Roofing felt is a cost-effective option for house wrap. It is cheaper than other house wrap materials, making it an attractive option for those on a budget.
2. Easy to Install
Roofing can be stapled or nailed to the house's exterior, making it a quick and easy option for contractors and DIY enthusiasts.
3. Moisture Barrier
Roofing felt is a moisture barrier that protects your home's walls from damage and mold growth.
4. Breathable
Roofing felt is also breathable, allowing water vapor to pass through it.
This is important because it allows moisture to escape from the house's walls, preventing mold and mildew growth.
5. Durable
Roofing felt is a durable material that can withstand harsh weather conditions.
It is also resistant to tearing and puncturing, which means it can provide long-lasting protection for the house's walls.
Disadvantages of Using Roofing Felt as House Wrap
While roofing felt can be used as a house wrap, it is not the ideal solution and comes with several disadvantages.
Here are some of the drawbacks of using roofing felt as house wrap:
1. Limited Water Resistance
Roofing felt is not as water-resistant as modern house wraps. It can become saturated with water, which can lead to moisture-related issues.
Additionally, roofing felt is not designed to be exposed to the elements for long periods, so it may not hold up like a dedicated house wrap.
2. Poor Air Permeability
This means it can trap moisture inside the walls, leading to mold growth and other moisture-related issues.
Additionally, poor air permeability can lead to a buildup of moisture inside the walls, which can cause damage over time.
3. Limited Durability
Roofing felt can tear more easily, leading to gaps in the protection it provides.
Additionally, roofing felt is not designed to be exposed to the elements for long periods, so it may not hold up like a dedicated house wrap.
4. Poor UV Resistance
Roofing felt is not designed to be exposed to UV rays for long periods.
Over time, exposure to UV rays can cause roofing felt to degrade, compromising its ability to protect the walls from moisture and other elements.
Recommendations for Using Roofing Felt
In hot, arid climates, roofing felt may provide adequate moisture protection for some buildings. Use caution and consult local building codes first. For best results, improve ventilation and incorporate additional moisture barriers.
Best practices with roofing felt:
When installing roofing felt, overlap seams by at least 6 inches and be sure to seal them thoroughly—also, tape around all joints and penetrations. Improving attic ventilation can help moisture escape.
Moisture prevention with roofing felt:
Take extra steps to prevent moisture issues when using roofing felt. Install a vapor retarder on the interior walls, seal all seams meticulously, and improve attic and soffit ventilation. Also, monitor humidity levels inside the home.
Sustainability Considerations
Roofing felt is made from petroleum-based asphalt so it has a larger carbon footprint than synthetic house wraps. Consider sustainability impacts when choosing your WRB.
Roofing Felt vs. House Wrap Comparison
| Factor | Roofing Felt | House Wrap |
|---|---|---|
| Cost | Lower ($0.15-0.30 per sq.ft) |
Higher ($0.75-1.25 per sq.ft) |
| Durability | 10-15 years | 20+ years |
| Breathability | Low (5 perms) | High (10-35 perms) |
| Water Resistance |
Moderate | High |
| Air Permeability |
Low | High |
| Ease of Installation | Moderate | High |
| UV Resistance | Low | High |
| Sustainability | Lower (petroleum-based) | Higher (synthetic) |
Making the Right Choice Matters
In conclusion, the materials we choose for our homes are more than just about cost or convenience.
The comparison between roofing felt and specialized house wrap underscores this fact.
From ensuring proper breathability to guaranteeing durability against the elements, the right choice can prevent moisture problems, mold growth, and potential damage during installation.
For those in moisture-prone areas, the decision becomes even more critical. As we've discussed, roofing offers certain benefits, but it might not always be the best fit for every situation.
Always evaluate your specific needs and consult with professionals when in doubt. Making informed choices today can save time, money, and potential headaches.
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