Mountain Bigfoot 180 Synthetic Roofing Underlayment

Mountain’s Bigfoot 180 delivers what Montana contractors need most: scheduling flexibility and installation efficiency. The 180-day UV exposure rating means crews can install it in June and not worry about final roofing until November. At 26 pounds per roll versus 208 pounds for comparable felt coverage, it transforms what used to be a two-person carry into a one-person job.

Performance That Matters in Montana

The strength-to-weight ratio changes the math on every job. Traditional 30lb organic felt weighs 8 times more while being 35 times weaker. That’s not marketing fluff — it’s measurable labor savings when crews haul materials up ladders all day.

The material maintains flexibility in cold weather and resists warping, wrinkling, and cracking. Temperature range runs from -20°F to 221°F, handling Montana’s temperature swings without the buckling problems that plague organic felt.

The UV exposure window solves real scheduling problems. Entry-level synthetics typically offer 30-60 day ratings. Bigfoot 180 provides 180 days (6 months). That’s the difference between rushing to close in before weather hits versus working at a profitable pace.

Installation and Coverage Specifications

Specification	Value	Source
Roll Dimensions	48” x 250’	manufacturer
Total Coverage	1,000 sq ft (10 squares)	manufacturer
Roll Weight	26 lbs	manufacturer
UV Exposure	180 days	manufacturer
Horizontal Laps	4 inches	manufacturer
Vertical Laps	6 inches	manufacturer
Warranty	40 years limited	manufacturer

Each roll provides 17% more coverage per course than standard 30lb felt. Simple math: fewer rolls to buy, fewer trips up the ladder, more square footage covered per day.

Critical installation detail: Must use corrosion-resistant plastic-cap or metal-cap nails with minimum 1-inch diameter. Fasteners should be flush and 90 degrees to the deck. Using staples or fasteners without 1-inch caps voids the warranty. No shortcuts here.

Material Composition and Certifications

The product uses 100% inorganic, recyclable synthetic woven polyolefin/polypropylene. No organic materials means no rot, no mold, no moisture absorption.

The certification list covers the bases:

• ICC-ESR 5197
• ASTM D8257 and D226 Types II
• Florida Building Code Approval (FL 42105)
• Texas Department of Insurance Listed
• CAN/CSA A123.3 (Canadian performance standard)

Who Should Consider Bigfoot 180

This product makes sense for contractors handling complex scheduling or weather-dependent projects. The 180-day exposure window provides insurance against Montana’s unpredictable weather patterns. Roofing contractors working multiple jobs benefit from the flexibility to dry-in early and finish later.

The Cool Gray top layer reduces heat absorption, making summer installations less miserable. Gripwalk gray surface on top provides superior traction while skid-resistant anti-slip coating on the underside ensures deck adhesion.

For steep-slope applications, the product works on roof pitches ≥4/12 as recommended, with a minimum of 2/12 requiring modified 50% + 1 inch overlap. Not recommended for slopes under 2/12.

The bottom line: Bigfoot 180 trades a higher material cost for measurable labor savings and scheduling flexibility. For contractors who value their crews’ time and need weather insurance, the math works.

Frequently Asked Questions

What makes Bigfoot 180 different from standard felt underlayment?

Bigfoot 180 is 35 times stronger and 8 times lighter than traditional 30lb organic felt. It provides 17% more coverage per course and offers 180-day UV exposure versus felt’s typical 30-day limit. The synthetic material won’t absorb water or buckle like organic felt.

Can regular roofing nails be used with Bigfoot 180?

No. The product requires corrosion-resistant plastic-cap or metal-cap nails with minimum 1-inch diameter. Using staples or fasteners without 1-inch caps voids the 40-year warranty.

What temperature range can this underlayment handle?

Bigfoot 180 operates from -20°F to 221°F. It maintains flexibility in cold weather and resists warping, wrinkling, and cracking through Montana’s temperature extremes.

How much area does one roll cover?

Each roll measures 48 inches by 250 feet, covering 1,000 square feet (10 squares). Rolls weigh 26 pounds, making them manageable for one-person carries.

What roof types work with Bigfoot 180?

The underlayment works with mechanically attached asphalt shingles, metal roofing systems, and tile roofing (concrete/clay). It’s compatible with standard wood decks including plywood, OSB, and wood sheathing.