Below Grade Waterproofing in Los Angeles, CA
Membranes and drainage installed on foundation walls and footings before backfill so groundwater never finds a way into the structure.
This work happens in one window, after excavation and before backfill, so there is no going back to fix it once the soil is pushed against the wall. The sequence is substrate prep, membrane application, protection board, then a drainage layer that carries water down to a footing drain instead of letting it sit against the wall. Sheet membrane or fluid applied membrane both work, the choice depends on the wall geometry and how many penetrations and corners need to be detailed.
What goes wrong is usually invisible until years later. Membrane installed over damp concrete never bonds right. Laps at corners get sealed in a hurry. Drainage board gets skipped to save a step, and hydrostatic pressure builds against the wall instead of draining away. The result is efflorescence on interior basement walls, standing water in elevator pits, or a slab that cracks from pressure nobody accounted for.
Los Angeles has expansive clay soils in a lot of hillside neighborhoods, and even though annual rainfall is low, it arrives concentrated in a few months, so drainage capacity matters more than total volume. Ask what membrane system is going in, how corners and pipe penetrations are detailed, and whether someone inspects the work before it gets covered.
Below Grade Waterproofing in progress
How it runs
Site prep
The excavated wall is cleaned and dried so the membrane has a sound surface to bond to.
Substrate repair
Cracks, honeycombing and form tie holes are patched before anything else goes on.
Membrane application
Sheet or fluid applied membrane goes on in a continuous layer up the wall.
Detail work
Corners, footings, pipe penetrations and cove joints get extra attention since these are where leaks start.
Drainage layer
Protection board and drainage composite go over the membrane to move water down to the footing drain.
Inspection and backfill
The wall is checked for punctures and complete coverage before soil goes back against it.
Other things we install
Tell us about the project.
Send the property, the address and what you are seeing. If it is urgent, the phone is quicker than the form.