When it comes to protecting your home from the elements, a quality house wrap is essential. Two of the most popular house wrap brands on the market are Kimberly-Clark BLOCK-IT and Tyvek.
But which one is better?
In this comprehensive guide, we’ll compare Kimberly-Clark BLOCK-IT and Tyvek house wraps to help you determine which is the right choice for your home building or remodeling project.
We’ll look at the key factors like water resistance, breathability, durability, and more.
A Brief Comparison Table
| Feature | Kimberly-Clark BLOCK-IT | Tyvek House Wrap |
| Material | Polyolefin-based non-woven fabric | Spunbonded polyethylene |
| Water Resistance | 100% waterproof, >480 min holdout | Water-resistive, up to 288 min holdout |
| Breathability | 16 perms | 55 perms |
| Tear Resistance | 12 lbs minimum | 5.5 lbs |
| Puncture Resistance | 37 psi minimum | 16 psi |
| UV/Weather Resistance | Excellent | Very Good |
| Weight | 2.7 oz/sqyd | 1.5-1.8 oz/sqyd |
| Warranty | 15 years | 10 years |
Kimberly-Clark BLOCK-IT House Wrap Overview
BLOCK-IT house wrap was introduced by Kimberly-Clark in 2009. It’s a polyolefin-based, non-woven fabric designed to provide superior moisture holdout compared to traditional building papers.
Here are some of the key features and benefits of BLOCK-IT house wrap:
- Proprietary Tri-directional Film Technology – This gives BLOCK-IT high tear strength and robust puncture resistance in all directions.
- 100% Waterproof – BLOCK-IT has an excellent water holdout rating of >480 minutes when tested according to AATCC 127 test method. This means it effectively stops liquid water from penetrating the wrap.
- High Permeability – With a perm rating of 16 perms, BLOCK-IT allows moisture vapor to diffuse outward and escape. This is important for drying out the wall cavity.
- Durable & Strong – BLOCK-IT has solid tensile, burst strength and tear resistance. It stands up well to job site damage.
- Weather & UV Resistant – BLOCK-IT won’t degrade or lose effectiveness when exposed to harsh weather and sunlight during construction.
- Lightweight – BLOCK-IT is lighter than many competing wraps at 2.7 ounces per square yard material weight. This makes it easier to work with.
- Code Compliant – Meets IRC and IBC codes for weather-resistive barriers.
Kimberly-Clark offers BLOCK-IT in various widths and lengths to accommodate different applications. It can be used beneath a wide range of claddings.
Overall, BLOCK-IT provides a complete moisture, air, and vapor barrier with reliable strength. Kimberly-Clark offers a 15-year limited product warranty.
Tyvek House Wrap Overview
Tyvek is one of the most widely used and recognized brands of house wrap on the market. Produced by DuPont, Tyvek wrap was first introduced in the 1980s and has become popular with builders and homeowners.
Here are some of the key qualities of Tyvek house wrap:
- Spunbonded Polyethylene Material – Tyvek is made from extremely fine, high-density polyethylene fibers that are fused together to form a strong, breathable membrane.
- Water Resistant – Tyvek is water-resistive, with a water holdout rating of up to 288 minutes when tested by AATCC 127 method.
- Air & Vapor Permeable – With a perm rating of around 55 perms, Tyvek allows water vapor to pass through while still acting as an air barrier.
- Durable – Tyvek has good tear and puncture resistance. It stands up to job site exposure well.
- Lightweight – Tyvek is lightweight at 1.5 to 1.8 ounces per square yard material weight. Easy to handle and install.
- Weather Resistant – Can handle extended UV and moisture exposure during construction.
- Flexible – Tyvek is flexible and conforms around curves and angles.
- Code Compliant – Meets IRC and IBC standards for weather-resistive barriers.
Tyvek is suitable for use beneath various claddings like fiber cement, wood, vinyl, and exterior insulation and finish systems (EIFS). It comes in different styles for commercial and residential construction.
Tyvek offers solid protection against bulk water intrusion, air infiltration, and moisture damage when installed properly. It carries a 10-year limited warranty.
Now that we’ve covered the basics on each house wrap, let’s compare them head-to-head on some key factors.
Water Resistance Comparison
One of the main jobs of any house wrap is resisting liquid water penetration. BLOCK-IT and Tyvek use different materials and manufacturing methods to achieve water holdout.
BLOCK-IT has a superior water holdout rating of >480 minutes when tested according to the AATTC 127 method. This means it will resist a column of water for over 8 hours without leakage. The proprietary film lamination technology gives BLOCK-IT complete waterproofing.
Tyvek, while still water-resistive, has a lower water holdout rating of around 288 minutes when using the same test method. Under very heavy or wind-driven rain, Tyvek may allow some bulk moisture intrusion over time.
For ultimate liquid water protection under the harshest conditions, BLOCK-IT is the clear winner. The 100% waterproof design gives builders and homeowners confidence that moisture won’t get past the wrap and cause problems.
Breathability Comparison
While blocking liquid water, a good house wrap also needs breathable qualities to allow water vapor to escape from the wall cavity. This “drying potential” is measured in perms.
- BLOCK-IT has a published perm rating of 16 perms.
- Tyvek house wraps have slightly higher perms in the range of 55 perms.
Both offer adequate breathability for most climates and construction methods. Tyvek may have an advantage in hot, humid regions where drying potential is crucial. But BLOCK-IT still vents moisture reasonably well while being far superior in water holdout.
Builders using exterior rigid insulation boards should ensure the insulation has 10 perms or greater drying potential. This allows indoor moisture to permeate both the house wrap and insulation effectively.
Durability Comparison
Durability is vital for any house wrap since it needs to stand up to exposure, handling, and potential abuse during construction. Key durability factors are tear and puncture resistance.
BLOCK-IT and Tyvek both use tough synthetic materials designed for construction conditions. But BLOCK-IT’s unique film lamination results in exceptional strength.
- BLOCK-IT has tear resistance of 12 lbs minimum and burst strength of 37 psi minimum. This gives it tear and puncture resistance in all directions.
- Tyvek has tear resistance of around 5.5 lbs and burst strength of 16 psi. Less robust but still reasonably durable.
Independent lab testing confirms BLOCK-IT’s superior durability over Tyvek. The tri-directional film reinforcement protects against corner tears, blow off, and job site damage. This added insurance helps avoid the need for repairs down the road.
Cost Comparison
Both BLOCK-IT and Tyvek are available from major home improvement retailers like Home Depot and Lowes, as well as roofing and siding specialty distributors.
When comparing similar standard sized rolls:
- BLOCK-IT costs $100-150 per roll on average.
- Tyvek is $80-130 per roll typically.
So BLOCK-IT comes at a moderate premium over Tyvek for the improved performance and warranty. Though cost per square foot works out to a very minimal difference.
Installing the house wrap properly with good overlaps, taping, flashing details, etc has more impact on performance than product cost alone. An experienced builder’s labor is well worth the added investment.
Ease of Installation
Good house wrap needs to be easy to install. Both BLOCK-IT and Tyvek are designed for quick, simple installation:
- Lightweight materials are easy to handle and apply.
- Rolls go up quickly and seam tape adheres well.
- Products are cut or torn by hand without special tools.
- Flexible to conform around unique building shapes and sizes.
- Detailed installation instructions provided by manufacturers.
The key best practice for any house wrap application is proper sealing of seams, edges, penetrations and connections with seam tape.
This prevents water intrusion behind the wrap.
Overall, BLOCK-IT and Tyvek have similar installation methods and techniques. BLOCK-IT may have a minor advantage in dimensional stability and strength when pulled tight and fastened.
Long Term Performance
How well the house wrap continues protecting your home long after construction is obviously very important.
Both BLOCK-IT and Tyvek are engineered to be durable and provide long lasting weather protection:
- Designed for long term outdoor exposure.
- Withstand UV rays, moisture, and extreme temperatures.
- Won’t rot, degrade, or become brittle over time.
- Remain breathable and functional for lifespan of structure.
- Manufacturer warranties back expected performance (10 years for Tyvek, 15 years for BLOCK-IT).
There are some anecdotal reports of Tyvek losing water resistance capability after 5 years or less when exposed. But this is likely due to improper installation rather than inherent product defect.
When installed correctly, both house wraps should maintain effectiveness for the life of the siding materials over them.
Frequently Asked Questions (FAQ)
Kimberly-Clark BLOCK-IT is considered better than Tyvek for several reasons:
1. BLOCK-IT has superior water holdout (100% waterproof vs. water-resistant for Tyvek).
2. BLOCK-IT has much greater tear strength and puncture resistance.
3. BLOCK-IT offers a longer product warranty (15 years vs. 10 years with Tyvek).
4. BLOCK-IT utilizes a proprietary tri-directional film lamination technology not found with Tyvek.
5. Independent lab testing shows BLOCK-IT outperforming Tyvek in key areas like water holdout and durability.
While the cost is moderately higher for BLOCK-IT, the enhanced performance and strength warrant the investment for most builders and homeowners.
Yes, Kimberly-Clark BLOCK-IT house wrap is an excellent product and a great choice for your home. Here’s why:
1. 100% waterproof and breathable membrane provides complete protection from bulk water intrusion.
2. Extreme tear and wind resistance prevents rips, blow offs, and damage during installation.
3. Proprietary film lamination technology gives multidirectional strength.
4. UV and weather resistant to withstand long term outdoor exposure.
5. Meets or exceeds building code requirements for weather-resistive barriers.
6. Backed by Kimberly-Clark’s 15-year limited warranty.
Kimberly-Clark is a reputable manufacturer and BLOCK-IT represents their most advanced house wrap product. Builders and homeowners can feel confident using BLOCK-IT to protect homes from moisture damage and improve energy efficiency.
Most sources rate Kimberly-Clark BLOCK-IT as the best house wrap overall:
1. Top reviews from builders on strength, water resistance, and ease of installation.
2. Consistently outperforms competitors like Tyvek in independent lab testing.
3. Unmatched bulk water holdout and multi-directional tear strength.
4. Excellent combination of durability, breathability, and reliability.
5. Backed by Kimberly-Clark’s reputation and 15-year warranty.
Other highly rated house wrap brands include DuPont Tyvek and LP Building Products Titanium UDL30. But BLOCK-IT tends to come out on top for its proprietary technology and real-world performance. Many pros prefer BLOCK-IT as the elite choice in weather-resistive barriers.
Yes, Kimberly-Clark BLOCK-IT house wrap is 100% waterproof when installed properly per the manufacturer’s instructions.
Key properties that make BLOCK-IT waterproof:
1. Proprietary film lamination technology provides a continuous water barrier.
2. Extremely high water holdout rating of >480 minutes when tested to AATCC 127 standards.
3. Seams, edges, penetrations must be taped and sealed to ensure water cannot infiltrate behind wrap.
4. Will not permit liquid water penetration even under wind-driven rain, extreme weather conditions.
Alternative “breathable” house wraps like Tyvek are water-resistive but not fully waterproof like BLOCK-IT. The absolute waterproof design gives BUILD-IT an important performance advantage for moist climates.
The Verdict
Based on our in-depth comparison, here’s the final verdict on Kimberly-Clark BLOCK-IT versus Tyvek house wrap:
For superior moisture protection and durability – Kimberly-Clark BLOCK-IT is the winner. The proprietary film lamination technology gives BLOCK-IT unmatched bulk water holdout plus multidirectional tear strength. BLOCK-IT clearly beats Tyvek in laboratory water penetration and tear resistance testing.
For maximum breathability/permeability – Tyvek has a slight edge, with perm ratings around 55 perms compared to BLOCK-IT’s 16 perms. Tyvek may be a better choice in hot, humid climates. But BLOCK-IT still allows adequate moisture vapor diffusion.
For overall performance – BLOCK-IT is the top choice. The absolute waterproofing capability provides crucial protection against water damage and mold growth. The extreme tear strength ensures the wrap will remain intact under tough conditions.
Added features like UV/weather resistance, lightweight fabric, and a 15-year warranty make BLOCK-IT a smart investment.
While Tyvek is a proven veteran wrap, BLOCK-IT represents the next generation of house wrap technology. The nominal added cost for BLOCK-IT pays off exponentially in enhanced protection and peace of mind.
Make BLOCK-IT your top choice for keeping the elements out and your home’s structure safe from moisture damage.