A liquid applied membrane is a waterproofing layer that is rolled, troweled, or sprayed on as a liquid and cures into a seamless, rubber-like barrier.
Understanding Liquid Applied Membranes
A liquid applied membrane arrives as a liquid or paste and cures into a continuous waterproof film. Common chemistries include polyurethane, polyurea, acrylic, and asphalt-modified products. Because there are no seams, the risk of leaks at laps and edges is much lower than with sheet goods.
Where Liquid Membranes Are Used
You will see them on balconies, plaza decks, roofs, planters, mechanical rooms, tunnels, and foundation walls. Some are used under tile or toppings, and others are left exposed with a wear coat. The product choice depends on movement, traffic, and exposure to sun or water.
Thickness and Reinforcement
A liquid membrane only works at the right thickness. Check wet film thickness as you apply, and add fabric reinforcement at cracks, corners, and joints when the manufacturer calls for it. Too thin a coat is the most common cause of early leaks.
Practical Tips for Applicators
Make sure the substrate is clean, sound, and dry enough for the product. Prime where required, respect cure times between coats, and flood test when the project allows it before covering the membrane.
Also Called
LAM, fluid applied membrane, liquid waterproofing
