Stone floor refinishing feels like a surface job until floodwater proves otherwise. After a flood, stone can look awful and still be salvageable. It can also look “fine” while the system underneath quietly fails. Flood damage forces fast choices, drying kit, access limits, insurer messages, and tenant stress, so it’s easy to chase visible puddles and miss hidden moisture that returns later.
Your first decision is salvage vs lock-in
Before you hire anyone or start sanding, pick one aim: keep options open during the first 24–72 hours. Two mistakes lock damage into the floor system:
- Sealing moisture inside the system by closing gaps, laying rugs, or finishing too soon.
- Grinding or refinishing while the system still holds moisture and silt.
That leads to the practical question: how do you find the worst moisture fast when the surface lies?
Check 1: Moisture is rarely where you think
Stone can look dry and still be soaked underneath. Surface sheen is a bad narrator after a flood, so build a quick moisture map. Imagine a ground-floor flat with three rooms hit overnight, one tenant still inside, and an adjuster date that keeps moving: you need fast, repeatable checks.
Start with the pattern, not the middle of the room. Water tends to park at edges, transitions, and under layers. Even strong dehumidifiers can dry the air while leaving damp pockets under skirting lines and thresholds, creating “progress” that isn’t progress, especially in damp weather.
Build a simple on-site moisture map using consistent checkpoints:
- Walk the perimeter and mark darker bands near skirting and door bars.
- Note cold patches, musty corners, and any “drummy” sound underfoot.
- Check transitions: hallway-to-bedroom, tile-to-stone, and any step-down areas.
- Photograph each zone with time stamps and short notes for the insurer file.
Once the moisture map shows likely reservoirs, move from “where” to “why.”
Check 2: The edge details predict the failure mode
Edges tell the story before the centre catches up. Inspect thresholds, door bars, skirting lines, and expansion gaps. Edge details show where water got trapped and what it carried with it.
Use edge evidence to sort the likely problem:
- Persistent dark bands at skirting lines often point to a trapped reservoir behind trims.
- A sour smell at a doorway transition often points to residue and dirty water at a choke point.
- Hairline cracks that track a threshold can hint at stress where the substrate moves.
Inspection guides your focus, but it can’t prove progress on its own.
Check 3–4: Drying success is measurable, not hopeful
Drying feels like progress until the numbers bounce back. Set simple pass-or-pause rules before you think about polishing or sealing. Clear rules reduce arguments with tenants, keep contractors aligned, and make insurer updates easier.
Check 3 is trend tracking, not a single reading. Pick the worst edge zone from your moisture map and record the same checkpoints over 48 hours. Use the same tool if you have one, or consistent observations if you don’t. You’re looking for a clean direction: down, flat, or up.
Check 4 is contamination gating. Floodwater can leave silt, salts, and grime inside grout lines and edges. Residue can drive odour and efflorescence even after the surface looks dry. Clean-up sequencing matters because aggressive scrubbing or early grinding can push grit deeper into pores.
A simple field routine keeps decisions grounded:
- Record baseline notes for the worst edge zone, then repeat at set times.
- Cycle equipment off briefly, then re-check for rebound smell or a returning damp band.
- Stop “drying only” if odour returns after cleaning; residue is still present.
Even if moisture trends improve, one final gate decides whether refinishing will last: bond and flatness.
Check 5: Test the bond and flatness before you touch the surface
A polish on a loose floor won’t stop future failure. Run a quick stability check while the system is still in “drying mode”:
- Tap-test for drummy zones and mark each hollow area on the moisture map.
- Watch joints for movement when you shift weight across a seam.
- Scan for cracks that follow straight substrate lines, not random surface scratches.
Treat stone floor refinishing as a timing choice, not a first move. If you’re scheduling stone refinishing in London, dust, noise, and access limits can change the best sequence for occupied homes. Choose the checklist path when moisture trends drop in the worst edge zones, odour stays gone after cleaning, and hollow zones stay limited. Slow down or escalate when moisture trends plateau, damp bands stay dark at edges, or residue keeps returning. Switch to replacement planning when hollow zones are widespread, joints move underfoot, or contamination needs clearance before anyone touches the surface.