Restoring a Beaverton Sunroom Sinking from Organic Soil Decay
When we were called to this cottage in Beaverton, the homeowners were dealing with a sunroom that was noticeably sinking and pulling away from the rest of the structure. Upon inspection, the cause became clear once we looked beneath the surface. The addition had been built over a large tree stump and loose soil — a recipe for long-term settlement issues.
Over time, as the organic material from the stump and roots naturally decayed, it left behind large empty voids beneath the structure. Combined with soil erosion common in waterfront areas, the ground could no longer support the weight of the sunroom. This resulted in sagging floor joists and interior flooring that had become dangerously uneven.
Because the issue was rooted deep in the sub-base, a surface-level repair would not provide a lasting solution. To properly address the problem, we began by removing sections of the floor to gain access to the affected joists and drilled small, strategic holes for our equipment. Using these access points, we injected high-density polyurethane beneath the structure.
The expanding material traveled into the deep voids left by the rotting stump and eroded soil, filling every pocket of empty space. As it expanded, it provided a controlled, precise lift that brought the sinking joists back to their original level position, restoring proper structural support.
The result is a sunroom that is now fully stabilized using a waterproof, non-invasive solution. Unlike traditional soil or gravel, our polyurethane material will not wash away or settle over time — even in the high-moisture conditions found in the Beaverton area. Best of all, the home was stabilized without the need for a full teardown or costly excavation to remove the stump. The homeowners now have peace of mind knowing their cottage is resting on a solid, long-term foundation built to withstand the elements for years to come.