Table of Contents
Overview
MFM Wind & Water Seal Underlayment is described as a self-adhering roof underlayment with a non-slip polymer film. It is intended for secondary waterproofing and is described as ideal for protection against ice dams and weather conditions such as wind-driven rain. The membrane is described as using a high-temperature, rubberized asphalt adhesive and being protected by a split release film that is removed once the underlayment is installed.
For readers looking to reference the product directly, see MFM Wind & Water Seal Underlayment.
Key takeaways
- This product is described as having high adhesion for ease of application and elimination of water movement under the membrane.
- It is described as applicable for use under any roofing material.
- It is described as a vapor barrier and is described as requiring proper ventilation during installation.
- It is described as compatible with most sealants and primers and described as applicable to plywood, OSB, foam insulation, house-wrap, rigid vinyl, and masonry when the surface is clean and dry.
- Buyers commonly mention very strong adhesion, material quality, and a heavy roll, along with handling challenges when the membrane sticks to itself or other surfaces.
What the product is designed to do
This underlayment is described as optimal for secondary waterproofing. It is described as ideal for protection against ice dams and weather conditions such as wind-driven rain, supported by a reliable, uniform thickness. It is also described as self-sealing around fasteners, which is presented as a functional characteristic of the membrane once it is in place.
The underlayment is described as applicable for use under any roofing material. It is also described as compatible with most sealants and primers, and it is described as able to be applied to multiple substrate types as long as the surface is clean and dry before application.
Materials, dimensions, and technical details
This product is described as using a high-temperature, rubberized asphalt adhesive and having a non-slip polymer film. It is described as having a split release film that is removed once the underlayment is installed. The roll specifications are described as follows.
| Detail | Described specification |
|---|---|
| Roll length | 67 ft. |
| Roll width | 36 in. (3 ft.) |
| Roll coverage | 200 sq. ft. |
| Roll thickness | 40 mils |
| Roll weight | 52 lbs. |
| Product dimensions | 36.33 x 8 x 8 inches |
| Test method codes | ASTM D 5147, ASTM D 1970, ASTM E 96, ASTM D 903/1970 |
For quick access to the same item, use Wind & Water Seal underlayment roll.
Installation and placement notes
This product is described as being installed by removing the split release film once the underlayment is positioned. It is described as having overlapping guidelines for easy installation, supporting alignment as the membrane is applied across the deck.
It is described as recommended to apply this underlayment in temperatures over 50°F on decks that have a minimum slope of 3:12. It is also described as having a minimum slope of 2 in. per foot for installation. The membrane is described as applicable to plywood, OSB, foam insulation, house-wrap, rigid vinyl, and masonry, as long as the surface is clean and dry before application.
This product is described as requiring proper ventilation during installation because it is considered to be a vapor barrier. It is also described as most effective when stored out of direct sunlight. Once applied, it is described as needing to be covered within 60 days of installation.
Performance characteristics described in the listing
This underlayment is described as having high adhesion for ease of application and elimination of water movement under the membrane. It is described as using a high-temperature, rubberized asphalt adhesive that will not crack or dry. It is described as high elongation, flexible, and able to accommodate the contraction and expansion of the application surface.
The membrane is described as self-sealing around fasteners. It is also described as applicable for use under any roofing material and described as compatible with most sealants and primers, which can be relevant when coordinating with other roofing accessories and sealant steps already planned.
To reference the product directly in your planning notes, see self-adhering roof underlayment.
Review patterns buyers commonly mention
Across buyer feedback, adhesion is frequently described as very strong. Material quality is also described positively. Buyers commonly mention that the roll is heavy, and some describe handling during application as challenging when the membrane sticks to itself or other surfaces.
Pros
- Very strong adhesion is commonly mentioned by buyers.
- Material quality is commonly mentioned by buyers.
- The product is described as self-sealing around fasteners.
- The product is described as having overlapping guidelines for easy installation.
Cons
- The roll is commonly described by buyers as heavy.
- Handling is commonly described by buyers as challenging when the membrane sticks to itself or other surfaces.
FAQ
What surfaces can this underlayment be applied to?
This product is described as able to be applied to plywood, OSB, foam insulation, house-wrap, rigid vinyl, and masonry, as long as the surface is clean and dry before application.
Is ventilation important during installation?
Proper ventilation is described as important during installation because the underlayment is considered to be a vapor barrier.
What temperatures and slopes are described for application?
It is described as recommended to apply in temperatures over 50°F on decks that have a minimum slope of 3:12. A minimum slope of 2 in. per foot for installation is also described.
How soon does it need to be covered after installation?
Once applied, it is described as needing to be covered within 60 days of the installation.
Does it self-seal around fasteners?
This product is described as self-sealing around fasteners.
How should it be stored before use?
This protective barrier is described as most effective when stored out of direct sunlight.