Old masonry houses breathe differently
Many Congress Park homes were built in the early decades of the twentieth century with solid brick walls and basements of brick, stone or early concrete. These walls were never meant to be perfectly waterproof. They absorb moisture from the soil and release it to the inside and outside air. An unfinished basement in such a house often stays reasonably healthy because the walls can dry. Problems tend to begin when the basement is finished with framing, fiberglass and drywall pressed against the masonry, trapping moisture where it cannot evaporate.
Radiator heating is the other local feature. Hot-water and steam systems run pipes through floors and walls, and a weeping valve, a corroded pipe or an air vent that spits water can wet flooring and plaster below for a long time. Boiler rooms in older basements may also contain pipe insulation that needs asbestos testing before anyone works near it.
Common Congress Park situations
- IfPlaster walls show stains below a radiatorHave the radiator valve and piping checked by a heating professional before cleaning or patching the wall.
- IfA finished basement smells musty along the masonry wallsExpect moisture trapped behind the finish; plan to open a section and consider a wall assembly that lets masonry dry.
- IfEfflorescence and crumbling mortar appear on basement brickAddress outside drainage and ask a mason about repointing with a compatible mortar.
- IfOld pipe wrap in the boiler room is damaged near the work areaLeave it alone and have it tested before mold work proceeds.
- IfThe house is in a designated historic districtExterior changes, such as window or masonry work, may need review; ask Denver's landmark preservation staff.
Materials more common here than in Hilltop
- Material
- Plaster on wood lath
- Mold consideration
- Sound plaster can often be cleaned; growth on lath behind failed plaster usually means removal
- Material
- Brick or stone foundation
- Mold consideration
- Clean and dry; avoid sealing moisture in with impermeable coatings on the inside
- Material
- Old-growth wood trim and floors
- Mold consideration
- Often worth cleaning and refinishing rather than replacing
- Material
- Radiator and boiler piping
- Mold consideration
- Leak source to repair; insulation may need asbestos testing
- Material
- Older paint layers
- Mold consideration
- Possible lead; use lead-safe practices when cutting or sanding
Before finishing or refinishing an old basement
- Fix exterior drainage and gutters first
- Have damaged mortar and masonry assessed
- Test boiler-room and pipe insulation before work nearby
- Choose wall assemblies that keep wood and paper off the masonry
- Run a dehumidifier through the first summer and watch readings
- Check with Denver about permits and any historic district review
General information for Hilltop, not a quote or professional advice. In an emergency, call 911.