GLOSSARY / BELOW GRADE

Negative Side Waterproofing

Waterproofing applied to the dry face of a structure — the inside of a basement wall — rather than the face the water arrives from.

WHY IT MATTERS

On an actual building

It is often the only option on an existing building, since the outer face cannot be reached without excavation. But water pressure acts to push it off rather than on, so it needs either a system that works within the concrete or active paths sealed by injection first.

COMMONLY MISUNDERSTOOD

What we most often have to correct

That it is equivalent to external tanking at lower cost. It manages water at the surface while the structure itself stays saturated.

QUESTIONS

Negative Side Waterproofing — questions we get asked

What does negative side waterproofing mean in waterproofing?

Waterproofing applied to the dry face of a structure — the inside of a basement wall — rather than the face the water arrives from.

Why does negative side waterproofing matter on a real project?

It is often the only option on an existing building, since the outer face cannot be reached without excavation. But water pressure acts to push it off rather than on, so it needs either a system that works within the concrete or active paths sealed by injection first.

What do people commonly get wrong about negative side waterproofing?

That it is equivalent to external tanking at lower cost. It manages water at the surface while the structure itself stays saturated.

NEXT STEP

Have a building showing this?

If a term on this page describes something you are looking at, a site inspection will tell you how far it has gone and what it needs. It costs nothing.

Mon–Fri 08:00–18:00 · Sat 09:00–16:00 · Jogeshwari West

Request a callback

Phone is the only required field. We call back to arrange the inspection.