Milwaukie’s mild wet winters drive constant moisture into older brick and stone foundations, especially in neighborhoods like Ardenwald and Island Station where homes sit close to the Willamette River. Water enters through hairline cracks in mortar joints and porous brick faces, then freezes and expands during rare cold snaps. Over time this spalls faces and pushes walls outward. Proper waterproofing starts with identifying whether the issue is surface saturation or below-grade hydrostatic pressure from Clackamas County clay soils.
We use breathable silane-siloxane sealers on above-grade walls so trapped moisture can still escape, while below-grade work requires a cementitious or elastomeric membrane that bonds to damp masonry without trapping salts. In Downtown Milwaukie and Hector Campbell, many 1940s–1960s homes have original lime mortar that must be repointed before any coating is applied. Skipping this step causes the new sealer to fail within two seasons because the mortar continues to wick water behind the film.
Edge cases include chimneys on the west side of homes that receive the heaviest wind-driven rain and garden walls built on fill near the river that shift seasonally. We never apply coatings to efflorescing surfaces until the source of moisture is addressed, and we always leave a small test patch so owners can watch how the masonry performs through the first winter. Code in Clackamas County requires that any work altering drainage around foundations be permitted if it changes grade more than six inches.
Technician insight
In Milwaukie the thing that catches most people out with masonry waterproofing is the clay soil along the Willamette that holds water against foundations for weeks after a storm. Homeowners in Ardenwald often seal only the visible brick and miss the fact that their 1950s mortar is still sucking moisture from below grade, so the sealer fails the first wet winter.
Ardenwald Foundation Seepage
Water was entering through the west wall of a 1952 brick home after every winter rain. We found the original mortar had eroded and the clay soil held moisture against the base. After repointing and applying a cementitious membrane below grade plus a breathable sealer above, the wall stayed dry through the following wet season.
How it works
- 1
Site Assessment
Walk the property with the owner, photograph every elevation, and note drainage patterns around the foundation, especially near the Willamette River or in low-lying sections of Island Station.
- 2
Mortar and Crack Repair
Rake and repoint deteriorated joints with appropriate lime or Type N mortar, then route and fill active cracks with backer rod and elastomeric caulk rated for masonry movement.
- 3
Surface Preparation
Pressure wash at low PSI to remove efflorescence and loose material, followed by a masonry cleaner if salts are heavy, then allow full drying before coating.
- 4
Waterproofing Application
Apply two coats of chosen sealer or membrane by brush and roller, paying extra attention to window sills, chimney bases, and any cold joints where water historically collects.
- 5
Final Walk and Care Instructions
Review the finished work, point out areas that will need periodic re-inspection after heavy winter rains, and leave written guidance on avoiding sealers that trap moisture in older brick.
Pricing
Cost depends on square footage, whether below-grade work is required, and condition of existing mortar.