Two kinds of floor damage
A fire touches floors in two ways. Smoke and heat leave residue and, near the fire, scorching or charring. The water used to put the fire out then soaks the boards and the subfloor underneath. In many older Park Hill houses the water does more harm to the floors than the flames.
Narrow oak strip flooring, and the fir common in upstairs rooms and kitchens of older homes, was usually laid over board subfloors on solid joists. The wood is often thick enough to sand more than once, which is good news after a fire. Surface soot generally comes off with cleaning, and light scorch marks can sometimes be sanded out.
Water is slower to show itself. Boards swell, edges lift into a cupped shape, and finish may whiten. The temptation is to sand right away, but sanding a floor that has not dried can leave it crowned once it shrinks back.
Reading the floor
| What you see | Likely cause | Typical next step |
|---|---|---|
| Black film that wipes off | Surface soot on the finish | Clean, then evaluate finish |
| Board edges higher than centers | Cupping from moisture below | Dry and monitor before deciding |
| Centers higher than edges | Crowning, often from sanding while wet | Wait for stable moisture, then reassess |
| Dark gray or black stains in the grain | Water reacting with oak tannins or prolonged wetting | Sanding test; boards may need replacing |
| Blackened, crumbly surface | Charring | Remove and weave in matching boards |
| Soft spots or bounce | Subfloor or joist damage | Structural check before any finishing |
A realistic sequence
Timing varies with the amount of water, the season and the drying equipment used.
- First days
- Remove standing water, take moisture readings, and photograph cupping. Start controlled drying of the floor and the space beneath it.
- First two weeks
- Continue drying and recording readings in the same spots. Many cupped floors flatten noticeably as they dry.
- When readings stabilize
- Compare to readings in an undamaged room. Decide which boards need replacement and source matching stock.
- After repairs above
- Sand and refinish last, once drywall dust, plaster work and painting are done, so the new finish is not damaged.
Common questions
- Can a floor that was soaked be saved?
- Often, if it is dried properly and promptly. The boards and subfloor need to come back to normal moisture before anyone decides they are ruined.
- Where can matching old boards come from?
- Sometimes from a closet or another area of the same floor that will be covered, or from architectural salvage. A flooring contractor can also mill new boards to match width and thickness.
General information for Park Hill, not a quote or professional advice. In an emergency, call 911.