Is roof cement a permanent fix?

It is a reliable sealant but not a permanent structural repair. Use it for sealing flashing edges and small patches. Major damage needs proper repair.

Can I apply roof cement in rain?

Wet-surface formulas can be applied in damp conditions for emergency repairs. Standard formulas need dry surfaces for best adhesion.

How long does roof cement last?

5-10 years typically. Inspect annually and reapply as needed at flashing edges and penetrations.

Roof Cement

Roofing

Sealant

$5-$20 per quart or gallon

Roof Cement: Asphalt-Based Roof Sealant (2026)

Prepared by Lumberama's Building Materials Team

|Last updated May 15, 2026|Sources & methodology

Roof cement is a thick asphalt-based sealant used to bond, seal, and waterproof roofing materials at joints, flashing edges, and small repair areas. It comes in trowel-grade and brush-grade consistencies for different applications. Some formulas can be applied to wet surfaces for emergency repairs.

Key Features

Asphalt-based waterproof sealant; Trowel and brush grade; Wet surface application available; Bonds to most roofing materials; UV and weather resistant

Specifications

Consistency: trowel-grade or brush-grade. Application temp: 40-100F. Coverage: varies by application thickness. Cure time: 24-48 hours. Available in caulk tubes

quarts

and gallons.

Applications

Flashing edge sealing; Emergency leak patching; Shingle tab bonding; Vent boot sealing; Gutter joint sealing

Installation Overview

Apply with trowel, putty knife, or caulk gun. Clean surfaces before applying when possible. Spread thin even layer for bonding, thicker for patching. Press materials firmly into cement. Allow to cure 24-48 hours.

Pros & Cons

Pros

✓ Waterproof seal; Easy to apply; Works on wet surfaces; Bonds most roofing materials; Good for emergency repairs

Cons

✗ Messy to work with; Difficult to remove; Not a permanent structural fix; Can crack over time; Stains clothing and surfaces permanently

Top Brands

GAF

Henry

Geocel

Black Jack

Code Requirements

Must meet ASTM D4586. Used as supplemental sealant per manufacturer roofing installation instructions. Not a substitute for proper flashing installation.

Buying Tips

Keep a gallon on hand for maintenance and emergency repairs. Wet-surface formula is worth having for rainy-day emergencies. Wear disposable gloves - this material is nearly impossible to clean off skin.