Table of Contents
Overview
MFM Wind & Water Seal Underlayment is a self-adhering roof membrane for secondary waterproofing. It uses a non-slip polymer film and rubberized asphalt adhesive.
However, its main purpose is protection against ice dams and wind-driven rain.
The membrane is designed to reduce water movement beneath the installed material. It also supports self-sealing around fasteners. These functions depend on correct surface preparation, placement, ventilation, and timely roof covering.
This self-adhering roof underlayment includes a split release film for positioning during installation.
Key takeaways
- The membrane supports secondary waterproofing beneath roofing material.
- It uses a high-temperature, rubberized asphalt adhesive.
- The non-slip polymer film includes overlapping guidelines for installation.
- The membrane self-seals around fasteners after application.
- Each roll measures 36 inches wide and 67 feet long.
- The roll covers 200 square feet and weighs 52 pounds.
What the product is designed to do
This membrane is intended for secondary waterproofing beneath roofing material. Also, it supports protection against ice dams and wind-driven rain.
Its adhesive targets elimination of water movement beneath the membrane. In addition, the material self-seals around installed fasteners.
The membrane works under any roofing material. However, the installation surface must remain clean and dry during application.
For focused details about this membrane, review the self-adhering roof underlayment guide.
Materials, dimensions, and technical details
The underlayment uses high-temperature, rubberized asphalt adhesive. Also, it features a non-slip polymer film and removable split release film.
| Detail | Specification |
|---|---|
| Roll length | 67 feet |
| Roll width | 36 inches |
| Coverage | 200 square feet |
| Thickness | 40 mils |
| Roll weight | 52 pounds |
| Dimensions | 36.33 x 8 x 8 inches |
| Test method codes | ASTM D 5147, ASTM D 1970, ASTM E 96, ASTM D 903/1970 |
The 40-mil waterproofing membrane combines flexibility with high elongation for surface contraction and expansion.
Installation and placement notes
Installation begins on a clean, dry surface. Next, the split release film supports controlled positioning before final adhesion.
The membrane includes overlapping guidelines for alignment. Also, its high adhesion supports application across the prepared roof deck.
Application is recommended above 50°F on decks with a minimum 3:12 slope. However, a minimum slope of two inches per foot also appears in the technical details.
Suitable substrates include plywood, OSB, foam insulation, house-wrap, rigid vinyl, and masonry. In addition, the membrane works with most sealants and primers.
The membrane functions as a vapor barrier. As a result, proper ventilation matters during installation.
Storage out of direct sunlight supports effective application. Next, the installed membrane needs roofing material within 60 days.
The 52-pound roll may require careful handling during positioning. Also, strong adhesion can make repositioning difficult after surface contact.
Use the peel-and-stick underlayment roll only after confirming the deck conditions and installation sequence.
Performance characteristics described
The membrane features high adhesion for easier application. Also, the adhesive supports elimination of water movement beneath the membrane.
The rubberized asphalt adhesive resists cracking and drying. In addition, the membrane remains flexible during contraction and expansion of the application surface.
High elongation supports movement across the installed substrate. Next, self-sealing around fasteners helps maintain the continuous membrane layer.
The non-slip polymer film supports footing during roof application. However, installation still requires suitable temperature, slope, ventilation, and surface conditions.
This rubberized asphalt roof membrane focuses on secondary waterproofing rather than room sound control.
Pros
- High adhesion supports firm contact with a prepared substrate.
- The membrane self-seals around fasteners.
- Overlapping guidelines support alignment during installation.
- Flexible construction accommodates surface contraction and expansion.
- The roll covers 200 square feet.
Cons
- The roll weighs 52 pounds.
- Strong adhesion can complicate handling when surfaces contact too early.
- Application requires a clean and dry substrate.
- The membrane requires proper ventilation because it forms a vapor barrier.
- Roofing material must cover the membrane within 60 days.
FAQ
What is MFM Wind & Water Seal Underlayment used for?
It supports secondary waterproofing beneath roofing material. Also, it targets protection against ice dams and wind-driven rain.
What surfaces support application?
The membrane applies to plywood, OSB, foam insulation, house-wrap, rigid vinyl, and masonry. However, each surface must remain clean and dry.
What temperature supports installation?
Application is recommended in temperatures above 50°F. Also, the roof deck must meet the specified minimum slope.
Does the membrane seal around fasteners?
Yes. The membrane includes self-sealing performance around fasteners after installation.
How large is each roll?
Each roll measures 36 inches wide and 67 feet long. In addition, one roll covers 200 square feet.
When must roofing material cover the membrane?
The installed membrane needs covering within 60 days. Next, coordinate the roofing sequence around that installation window.