Key facts: Flash Flood Cleanup in Historic Downtown
- The city describes the downtown area as bounded roughly by West Belt Line Road, Highway 67 and Cooper at Broad.[1]
- The EPA warns flood water can contain bacteria or chemicals that affect health.[2]
- EPA's lead rule requires certification for anyone paid to disturb paint in pre-1978 housing or child-occupied facilities.[3]
The route
How water enters an old building
Older buildings often have details that modern construction avoids: low door sills at street level, old basement or cellar openings, ventilation gaps under raised floors and walls without modern damp-proofing. Pavement levels may have risen over the decades as well, leaving a threshold that once sat above the street now close to it. So when a storm overwhelms local drains, water can reach a building from below as well as through the door.
Under a raised floor, the void may fill and drain again with nobody seeing it. Check it after any flood, because silt and contaminated water left down there will keep the whole building damp and may smell for a long time.
Keep or remove
Contaminated water and old materials: what to do
| Material | Usual modern answer | In an older building |
|---|---|---|
| Lime plaster on lath | Remove if soaked | Clean and dry may be possible; get advice |
| Solid old doors and trim | Clean and dry | Remove, clean, dry flat and refit |
| Old wood floors | Depends on contamination | Clean thoroughly, dry slowly |
| Later drywall or paneling | Remove | Remove, and see what's behind it |
| Insulation in the void | Remove | Remove |
| Carpet over old boards | Remove | Remove, and check boards beneath |
The work
A careful flood cleanup in an older building
- 1
Make it safe
Check for electrical, gas and structural hazards first.
- 2
Photograph original features
Record them before anything moves.
- 3
Remove water and silt
Include the void under a raised floor.
- 4
Sort materials
Decide what's truly lost, and what can be cleaned.
- 5
Remove and label
Number doors, trim and other pieces, and keep them out of the wet.
- 6
Clean and sanitize
Use products that suit old surfaces, and ask before using harsh ones.
- 7
Dry slowly and monitor
Controlled drying is gentler on old wood and plaster.
Businesses
Storefronts and shared walls
Some buildings downtown are shops or mixed-use buildings. Check who is responsible for what under your lease, and tell the other party in writing right away. Business policies may have different flood provisions than home policies, so read yours or ask your agent. Stock and equipment should be photographed before anyone moves or discards them.
Shared walls bring in a neighbor. Water may have crossed under a party wall into the building next door, and drying one side while the other stays wet won't work well. Talk to each other early. This site is mainly about homes, so ask the contractor whether commercial work is something they handle.
- Check the lease
- Tell the owner in writing
- Photograph stock
- Coordinate with next door
Designation
Historic status when you rebuild
The city's Historic Designation Marker program has existed since 2006, and it exists to protect historic resources in this area.[1] Cedar Hill also has five homes on the National Register.[5] Flood repairs may be urgent, but it pays to call the city before replacing doors, windows or visible finishes, as the city's page doesn't set out what approvals apply. Keep samples and photographs, so that repairs can match.
Plumbing, electrical and structural repairs still go through normal channels, with state-licensed trades registered with the city.[6]
Long-term drying
Getting moisture out of thick old walls
Dense old walls can take a long time to dry, sometimes well after the rooms feel normal. Don't rush to apply new paint or modern sealers, which can trap moisture in a wall that needs to breathe. Compare readings with parts of the building that stayed dry, and ask anyone doing the repairs which paints and plasters suit older materials.
Prevention
Protecting the building before the next storm
- Keep street drains near you clear, and report blockages.
- Maintain gutters and downspouts, so the wall bases stay dry.
- Keep vents under raised floors clear, but know how water can enter them.
- Store documents and valuables well above floor level.
- Photograph original details now, while they're in good condition.
Further reading
More on these buildings
See flash flood cleanup for the general process and the Historic Downtown page for the materials. Extraction and drying downtown deals with slow drying in more detail.
Silt in walls
Silt in old wall cavities
Silt is harder to deal with in an old building, because many old walls and floors have gaps and voids where it can settle. Left there, it holds moisture and smells long after the rooms look clean. Where a wall has to be opened anyway, look at the bottom of the cavity and clean it out. Where it doesn't, ask whether a small access point at the base could allow an inspection. Keep the openings neat and in discreet places, like behind a baseboard that has already come off, so that repairs can be hidden when the trim goes back.
Later checks
Check the doors and windows again later
Old doors and sashes may swell and then shrink as the building dries, so they may bind and then rattle. Leave planing or refitting until the readings have settled, and photograph any cracks that appear so that you can tell whether they grow.
Cleaners
Ask before using harsh cleaners
Harsh cleaners can damage old finishes, so test a hidden spot first and ask a specialist about anything valuable.
Questions
Downtown flood questions
Must soaked plaster be removed after a flood?
Not automatically, though contaminated water makes the case stronger. Ask someone experienced with old buildings. Plaster that has lost its bond or absorbed sewage is usually lost, but sound plaster can sometimes be cleaned and dried.
Can old doors and trim be saved after contaminated water?
Often, since solid wood is cleaner to work with than porous materials. They can be removed, cleaned, dried flat and refitted. Old paint may contain lead, so ask for lead-safe methods before anyone strips or sands them.
Who deals with a flooded shared wall downtown?
Each owner handles their own side, usually in consultation with one another, and leases may add detail. Speak to your neighbor early and tell your insurer, because drying only one side rarely works well.
Do I need city approval for flood repairs on a historic building?
Normal permits still apply where required. Designated buildings may have further requirements, and the city's page doesn't spell out approvals, so call the city before changing visible features.
