PL Heavy Duty Construction Sealant

Available Sizes: 9.5 fl oz (280 ml)


Color When Dry: White



Where to Buy


Loctite® PL Heavy Duty Sealant

Durable Seal, 5x Stretch, Limited Lifetime Guarantee

Safety Precautions

Wear gloves and wash hands after use.

Tools Typically Required

Utility knife, caulking gun


Surface Preparation
Ensure all surfaces are clean and free of old caulk, grease, dust, ice, snow, frost, surface water and other contaminants. While PL Heavy Duty is generally considered a non-priming sealant, special circumstances or substrates may require a primer. It is the user's responsibility to test substrate compatibility and the adhesion of the cured sealant on a test joint before applying to the entire project.

General Preparation
The temperature of the product, the surfaces and the working area should be between 0°F (-18°C) and 140°F (60°C). For best performance, store cartridge at room temperature at least 24 hours before use. Cut plastic nub of cartridge then screw on plastic nozzle. Insert cartridge into caulking gun, cut nozzle at a 45° angle to desired bead size (3/8'' is recommended for optimal joint protection).


Using a caulking gun, apply sealant with steady pressure, forcing sealant into joint. If the depth of the joint exceeds ½'' the use of a backer rod is recommended. PL Heavy Duty will not pop or splatter and will dispense smoothly on extrusion from the cartridge. Tooling of the sealant is allowed. Full cure may take 24-72 hours or longer depending on ambient conditions and volume of sealant used. Sealant is paintable in 1 hour. Latex paint is recommended. If using oil based/alkyd paint, a latex primer should be used first.


Clean tools and uncured sealant residue immediately with mineral spirits or paint thinner. Cured sealant must be carefully cut away with a sharp-edged tool.