When it comes to purchasing a vapor barrier fiberglass insulation, the average consumer typically lacks this knowledge. Ultimately, they have to rely on sales representatives, hoping to extract some objective information. To which I say, “Don’t hold your breath.” I’ve been in the insulation industry for over 40 years, so hopefully you will consider me qualified to write this insulation blog.
The four popular metal building insulation types –
•Vapor Barrier Fiberglass Insulation
•Spray Foam Insulation
•Reflective Insulation
•Foam Board
The one considered by many to be the most cost-effective is a vapor barrier fiberglass insulation for pole barns and metal buildings. It is a preferred insulation for DIY projects due to its relatively simple installation process. The insulation adds not only a vapor retarder but is also a strong, puncture and tear-resistant material.
The four types of vapor barrier fiberglass insulation:
•WMP-VR-R: for basic performance and cost savings.
•WMP-10: for its standard strength and pleasing aesthetics.
•WMP-30: for heavy-duty environments with high humidity.
•WMP-50: when only the most durable and vapor-resistant solution will do.
Each facing serves has its unique features and specifications, and plays a specific role based on project demands. Although you won’t go wrong choosing any of these vapor barrier insulation types, selecting one with qualities more specific to your unique project ensures your insulation performs optimally. This article will focus on the features, benefits, and purposes of each of these facings, along with additional information on building types that complement a facing. Hopefully, it will help you make an informed choice about the fiberglass facing.
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WMP-VR-R fiberglass facing: Solid Performance and Price-Friendly
Of the four facings, the WMP-VR-R fiberglass facing is the most popular, likely because it is the best known and budget-friendly, but it also has objective merit. It features a tri-directional fiberglass scrim bonded to a layer of aluminum foil and kraft paper. It has a low permeance rating of 0.09 perms, which means it protects the insulation from moisture accumulation due to condensation. The insulation also has structural integrity: It has a tensile strength rating of 20 lbs. per (machine direction) and 10 lbs. per (cross direction). It’s also compliant with ASTM E84 standards for flame and smoke, so it meets most standard building codes. Lastly, as a bonus, it has an attractive white polish appearance.
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WMP-10 fiberglass facing: Handles the Everyday Stuff
When analyzing this facing, I concluded that the WMP-10 fiberglass facing is very similar to the WMP-VR-R, featuring a reinforced fiberglass scrim, kraft paper, and aluminum foil laminate. However, it has a tighter scrim pattern, making it a stronger, tear-resistant facing. Both insulations have the same 0.09 per ratings and meet the same ASTM E84 flame/smoke standard. For everyday use, the WMP-10 fiberglass facing is the choice if you want a more tear-resistant fabric.
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WMP-30 fiberglass facing: When an Upgrade Is Needed
Sometimes, you need a workhorse insulation facing for high-humidity areas. Well then, look no further than the WMP-30 fiberglass facing. It, too, features a high-strength kraft paper base, aluminum foil, and reinforced fiberglass scrim, but its uniqueness lies in its permeance rating of less than 0.02. This means it 30 provides excellent vapor control. Other key attributes: This facing can withstand 50 pounds of force per inch before tearing. Finally, this finish also offers a clean, attractive, reflective white appearance.
WMP-50 fiberglass facing: The Heavy Weight Champion
There are many weight divisions in boxing, but we all know the heavyweight champion is the top dog. That’s the best description for the WMP-50 fiberglass facing. If you need the highest tear-resistance combined with vapor barrier protection, it’s the one. When a cold storage facility, industrial plant, or high-traffic building is constructed, this insulation is used to protect it.
Like the other insulation types, the WMP-50 fiberglass facing features a tough, heavy-duty kraft paper, a tri-directional fiberglass scrim, and thick aluminum foil, with a permeance rating of under 0.02 perms, making it one of the most effective vapor retarders available. Needless to say, it is also compliant with ASTM E84 standards.
Summation of vinyl-faced fiberglass insulation:
WMP-VR-R
A perfect combination of strength and moisture control at a great price. The WMP-VR-R Plus is a familiar face to the general public, which is why it is the leading seller.
WMP-10
It is probably the best choice for those with tight budgets. It is lighter and easier to install. It works well in normal conditions.
WMP-30
Stronger than WMP-10 or VR-R. Suitable for humid climates.
WMP-50
The toughest and strongest.
Installing Vapor Barrier Fiberglass Insulation in a metal building
1st Step:
Take the time to measure the length of each bay. This way, you know what cut dimensions you need.
2nd Step:
You will then need to cut the faced fiberglass insulation to the particular bay length. Remember, the facing side points to the interior of the building.
3rd Step:
You will roll the insulation over (on top of the purlins (for the roof) or girts (for the walls)). Some lay the insulation between the purlin and girts, but this should be done when you are installing a second layer, which is a single-layer instruction guide.
The key is to keep the fiberglass uncompressed, which helps maintain R-value.
4th Step:
I recommend buying double-sided tape and securing it to your steel members. This will keep the insulation from blowing away or sagging while you’re installing the sheeting.
5th Step
You will secure the insulation by installing the sheeting (metal panels) directly over the installation. As you screw the sheeting into the framing, it compresses and locks the insulation into place.
6th Step:
This is the step most often missed. You should tape all seams where facings meet. This maintains the vapor barrier’s continuity and supports thermal efficiency.
I hope this article has sufficiently covered the key issues regarding the differences between the facings and shed insight on which insulation best meets your construction needs. As a bonus, we hope our vapor barrier fiberglass insulation installation instructions are beneficial and straightforward.
