Best Liquid Tar Roof Sealants and Coatings for Flat and Low-Slope Roofs
Choosing the right liquid tar or tar-like roof coating can protect flat and low-slope roofing from leaks, UV damage, and weathering. This guide reviews top liquid rubber and asphalt-based sealants designed for roofs, foundations, gutters, and more. Each product is evaluated for durability, coverage, and ease of application to help homeowners and contractors select dependable protection.
| Product | Brand | Coverage (approx.) | Volume | Key Strength |
|---|---|---|---|---|
| Liquid Rubber Waterproof Sealant – 1 Gallon | Liquid Rubber | 15 sq ft (flat surfaces), 30 sq ft (vertical) | 1 Gallon | Exceptional elongation and flexibility |
| Liquid Rubber Waterproof Sealant – 1 Quart | Liquid Rubber | 15 sq ft (flat surfaces) | 1 Quart | Same durable, flexible formula in a smaller container |
| Liquid Rubber Waterproof Sealant – 5 Gallon | Liquid Rubber | 15 sq ft per gallon (3-4 coats) | 5 Gallons | Cost-effective for larger projects |
| Black Jack 6190 Roof and Foundation Liquid Asphalt Coating | Gardner-Gibson | Various, for roofs and foundations | 5-Gallon Pail | Odorless, solvent-free, US-assembled |
| SENVEN Waterproof Sealant | SENVEN | Similar coverage to Liquid Rubber products | 1 Gallon | Industrial-strength bitumen formula with UV resistance |
Note: All products reviewed are suitable for flat or low-slope roofs and can also be used for foundations and other exterior surfaces. Coverage varies with surface porosity and the number of coats applied. Always follow manufacturer guidelines for surface preparation and cure times.
Liquid Rubber Waterproof Sealant — 1 Gallon
This industrial-strength bitumen formula creates a seamless waterproof membrane across flat and low-slope roofs, foundations, gutters, and more. The product is designed to remain flexible with movement and temperature fluctuations, resisting cracking and UV damage. Coverage estimates indicate 1 gallon yields 15 sq ft with 3-4 heavy coats to reach a 60-80 mil membrane on flat surfaces, and about 30 sq ft on vertical surfaces with 2-3 heavy coats. It serves as a durable alternative to traditional tar or patch products, emphasizing flexibility and long-term protection.
Liquid Rubber Waterproof Sealant — 1 Quart
Similar to the gallon version, the quart provides the same premium formula in a smaller package, making it suited for smaller repairs or spot treatments. It offers over 950% elongation, maintaining adhesion during building movement and thermal expansion. Prospective users should plan for multiple coats to achieve the intended membrane thickness on flat roofs, with slightly fewer coats on vertical surfaces.
Liquid Rubber Waterproof Sealant — 5 Gallon
Designed for larger roofing projects, the five-gallon size delivers the same durable, flexible membrane with high elongation. Coverage estimates suggest 1 gallon covers 15 sq ft on flat surfaces with three to four heavy coats. This option is cost-effective for coating expansive roofs, foundations, or multiple surfaces requiring a robust seal against water infiltration and UV exposure.
Black Jack 6190 Roof and Foundation Liquid Asphalt Coating
Black Jack 6190 is a water-based asphalt emulsion coating designed for roofs and foundations. It is odorless and solvent-free, suitable for waterproofing, resurfacing, and sealing. The product is marketed as shell-friendly for easy application and is manufactured in the United States. For users seeking an asphalt-based option with minimal odor and straightforward application, this coating provides a traditional alternative to rubbery sealants, though it may require more coats for thick membranes.
SENVEN Waterproof Sealant
SENVEN emphasizes an industrial-strength bitumen-based formula creating a seamless waterproof membrane for flat and low-slope roofs, foundations, gutters, and other exterior surfaces. Its 950% elongation ensures adhesion during building movement and temperature changes. The product is designed to resist cracking, peeling, and UV damage, offering a durable rubberized coating with long-lasting protection. Coverage follows the standard 15 sq ft per gallon on flat surfaces with multiple coats, similar to other premium sealants.
Leak Stopper Rubber Flexx Coating
Leak Stopper offers a flexible rubber coating intended for boats, roofs, tents, machinery, and buildings. The quart-sized container provides a fast-curing, waterproof layer suitable for various exterior and interior applications. While marketed for broad use, its sealing properties align well with roof repairs and preventative maintenance requiring a rubberized membrane that expands and contracts with weather conditions.
Waterproof Sealant Black Waterproof Coating 35oz
SENVEN’s 35-ounce variant presents a compact option for quick repairs on flat and low-slope roofs, foundations, gutters, and indoor/outdoor walls. The smaller canister is suitable for patch jobs and spot repairs, offering the same durability and UV resistance properties as larger containers in the line.
Buying Guide: Key Purchase Considerations for Roof Sealants
- Surface type and slope: Flat or low-slope roofs benefit from sealants designed for moisture control and surface penetration. Vertical surfaces like foundations also require thicker membranes or multiple coats.
- Membrane elasticity: Materials with high elongation (above 900-1000%) tolerate building movement and temperature changes without cracking or peeling.
- Drying and cure times: Some coatings cure quickly, enabling faster turnarounds, while others require longer cure windows and weather constraints.
- Application method: Options include brush, roller, or spray. Consider availability of tools and the complexity of the roof area when selecting a product.
- UV resistance and durability: UV exposure can degrade coatings; choose products formulated to resist sun damage for long-term protection.
- Environmental and odor considerations: Odorless or low-VOC options may be preferred for installations in occupied spaces or environmentally sensitive areas.
- Coverage and project size: Larger projects benefit from 5-gallon or bulk containers, while spot repairs can be managed with 1-quart or 1-gallon options.
- Compatibility: If applying over existing coatings or on concrete, verify compatibility to ensure adhesion and performance.
- Maintenance needs: Some products offer durable, long-lasting protection, reducing maintenance frequency, while others may require periodic re-coating for sustained waterproofing.
In summary, for flat and low-slope roofs, premium liquid rubber sealants (1 gallon/1 quart/5 gallon) provide highly flexible, UV-resistant protection with substantial elongation. Asphalt-based coatings (Black Jack) offer traditional, odorless options with straightforward application, while SENVEN and Leak Stopper products provide versatile sealant choices for various surfaces. When selecting, prioritize surface type, required membrane thickness, and the project scale to ensure reliable, long-term waterproofing.