High Water Table Basement, St. Johns
A water table sitting only a few feet below the slab, waterproofed mid-January while water was actively coming in.
Location
St. Johns, Portland
Service
Basement Waterproofing
Duration
4 days
Completed
January 20, 2026
The situation
Sitting on the lake plain, this basement took water from below rather than through the walls, driven by the water table (opens in a new tab) rather than rainfall. It was arriving through the slab and cove joint continuously from February onward, not just during storms.
What we did
Full-perimeter below-slab waterproofing installed in January while the ground outside was frozen solid, one of the reasons interior work matters here. Bedded in washed stone, wrapped in filter fabric, with clean-outs at all four corners.
The outcome
The basement stayed dry through the wet season that began six weeks later. Moisture readings taken in April came back at 45-49% relative humidity (opens in a new tab) against 71% before the work.
Water arriving along a line rather than at a point is hydrostatic pressure (opens in a new tab) , and no amount of crack repair would have touched it. The 2026 cost article explains where full-perimeter pricing comes from, and our process explains how we confirm the diagnosis first.
By the numbers
| Metric | Result |
|---|---|
| Linear feet treated | 112 ft |
| Installed in | January |
| Humidity before / after | 71% to 45-49% |
| Warranty | Lifetime transferable |
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