Basement seepage is the most expensive water problem in Nigerian construction, and the most commonly mis-priced. The reason is simple: most basement waterproofing in Nigeria is applied negatively - from the dry side of the wall - because positive-side application was missed during construction and the only way to fix it after the fact is to dig back to the wall, or to inject.
Why negative-side waterproofing fails
A negative-side coating has to resist hydrostatic pressure pushing through the wall toward the room. Even excellent crystalline products are working uphill in those conditions. They will hold for three to five years, then fail at the construction joints.
What actually works
The permanent fix is a combination - crystalline waterproofing inside, polyurethane injection at the joints, drainage management outside if access permits. We write the protocol per site. The cost is higher than a single coat. The result lasts.
When to call
If your basement smells of damp, or you see efflorescence on the walls, you do not have a cosmetic problem. You have a structural-protection problem, and it gets more expensive every month you wait.
Got a building doing what this article describes?
Send us a WhatsApp message with a few photos. We'll tell you what we think is happening and what it would take to fix.
