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Malarkey 401 NEX Polymer Modified Self-Adhering Ice & Water Underlayment, 2 Squares per Roll
Regular price $141.90Orders start at $399 — combine any items to reach the minimum. Learn more
Malarkey 401 NEX Polymer Modified Self-Adhering Ice & Water Underlayment, 2 Squares per Roll
Malarkey 401 is a polymer-modified self-adhering (SA) ice and water underlayment for steep-slope roofs, supplied in Black. Each roll provides 2 squares of coverage, protecting eaves, valleys and vulnerable roof areas beneath the finished shingles. It pairs with Malarkey shingle systems as part of a complete roof assembly.
Key Features:
- Self-adhering: The SA underlayment adheres directly to the deck without mechanical fastening across the field.
- Polymer modified: Made with NEX polymer-modified asphalt technology from Malarkey Roofing Products (Holcim).
- Ice and water barrier: Designed as an ice and water underlayment for eaves, valleys and leak-prone areas.
- 2 squares per roll: Each roll covers 2 squares (200 sq. ft.) before laps.
- Black surface: Supplied with a black surface for use under finished shingle courses.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Malarkey |
| Sell unit | 1 roll, 2 squares |
| Product line | 401 NEX Polymer Modified SA Underlayment |
| Available colors | Black |
| Material | Polymer-modified asphalt self-adhering underlayment |
| Coverage per unit | 2 squares per roll |
| Category | Steep-slope roofing underlayment |
| Intended use | Ice and water underlayment for steep-slope roofs |
Coverage & How Much You Need:
One roll covers 2 squares (200 sq. ft.) before lap deductions. For eaves protection, run the underlayment from the eave up the slope per code or manufacturer instruction; for valleys, extend it well beyond the valley centerline on each side.
Fit and Compatibility:
Intended for use under Malarkey steep-slope shingle systems as part of a complete roof assembly. Starter, field shingles and accessories are sold separately.
Frequently Asked Questions (FAQ):
Q: What is included in one order?
A: One roll of Malarkey 401 self-adhering ice and water underlayment, providing 2 squares of coverage.
Q: How much area does one roll cover?
A: Approximately 2 squares (200 sq. ft.) before lap and waste deductions.
Q: Where should this underlayment be used?
A: It is designed for ice and water protection at eaves, valleys and other vulnerable areas of steep-slope roofs.
Q: Does it need fastening?
A: It is a self-adhering membrane; follow the manufacturer's installation instructions for primer and adhesion requirements.
Q: What color is it?
A: It is supplied in Black.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Self-adhering ice and water membrane at eaves and valleys is one of the best investments against wind-driven rain and ice damming. Apply to a clean, dry deck within the manufacturer's temperature range for good adhesion, and roll it firmly to seat the lap seams. Use the 2-square roll for detail areas and order additional rolls based on the eave and valley linear footage.
Self-adhering membranes can be slippery when the release liner is removed; wear appropriate footwear and follow fall-protection requirements during installation.
Order Malarkey 401 NEX self-adhering ice and water underlayment rolls today.
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