SIPA 100 GSM Synthetic Waterproof Roof Underlayment 48 x 250 ft

Our review of the SIPA 100 GSM Synthetic Roofing Underlayment finds it best suited to contractors and experienced DIYers who need a lightweight, water resistant underlayer for sloped commercial or residential roofs. The single biggest reason to consider this product is its combination of a non-woven top surface for traction and a waterproof coil layer that claims extended UV resistance, which makes it practical when re-roofing or installing metal cladding under conditions where temporary exposure may occur. Installation notes and real-world feedback are mixed on adhesive performance, but performance specifications and approvals make it a credible underlayment choice.

Key Features

• 10 square roll: Each roll covers 1,000 sq ft, letting installers calculate material needs quickly and reduce seams on larger roofs.
• 100 GSM weight: The lightweight synthetic fabric is easier to handle than heavy felt, which can speed up installation on steep slopes.
• Enhanced traction top surface: The unique non-woven top fabric helps maintain secure footing for roofers during installation and in wet conditions.
• Water resistant coil layer: A waterproof and anti-aging coil layer provides a double waterproof barrier under shingles or metal cladding.
• Code approvals and UV exposure: Meets or exceeds ASTM standards and is TDI Listed CCRR #AC207 and FBC Approved #FL17188 with up to 60 days ultraviolet exposure.
• Stable material: Designed not to buckle, warp, or crack, which preserves the underlayment integrity during installation and weather cycles.

Who It's For

This underlayment is aimed at roofing contractors and homeowners doing major roof projects on sloped residential and commercial roofs who need a tested synthetic product with recognized approvals. It is particularly useful when installers want a light, traction-friendly sheet that can tolerate limited ultraviolet exposure before final roofing is applied.

Those who should look elsewhere include users needing an underlayment with factory-applied adhesive in every application or projects requiring a heavy, self-adhering ice-and-water product; customer feedback indicates adhesive strength can be mixed, so jobs that demand permanent self-stick performance in all conditions might favor alternative products.

Pros & Cons

Pros

• Lightweight 100 GSM construction makes handling and layout faster on large roof areas.
• Non-woven top surface offers improved traction and reduced slip risk during installation.
• Meets multiple standards and approvals, including ASTM performance levels and TDI/FBC listings, which supports code compliance.
• Water resistant coil and anti-aging layers provide double waterproofing under shingles or metal cladding.

Cons

• Some customers report mixed durability and that adhesive strength is not consistent, so additional fastening or seam treatment may be required.
• Not a substitute for dedicated self-adhering ice-and-water membranes where full adhesion is required.

Specifications

Brand	SIPA
Weight	100 GSM
Roll Size	48 in x 250 ft
Coverage per Roll	10 square (1,000 sq ft)
Approvals	TDI Listed CCRR #AC207; FBC Approved #FL17188
UV Exposure	Up to 60 days

Our Verdict

The SIPA 100 GSM Synthetic Underlayment is a practical, code-friendly choice for roofers and experienced homeowners who need a lightweight, water resistant underlayer with good traction and UV tolerance. It represents solid value for typical sloped roofing projects, though teams expecting consistent factory-applied adhesion should plan for mechanical fastening or seam reinforcement.

Frequently Asked Questions

Can this underlayment be left exposed during reroofing?
Yes, it is rated for up to 60 days of ultraviolet exposure, making it suitable for typical reroofing timelines where temporary exposure occurs.

Is it self-adhering?
Customer feedback indicates adhesive strength is mixed; this product is primarily a water resistant synthetic underlayment and installers often use mechanical fasteners or additional seam treatment when permanent adhesion is required.

What roof types is it compatible with?
It is intended for sloped commercial and residential roofs and works under asphalt shingles or metal cladding as a waterproof underlayer.