Filling normal winter gaps
The filler is compressed when the boards expand in summer and pushed out or cracked. It has to be removed, and it may have damaged the board edges.
Avoided by: Identifying normal seasonal movement and leaving it alone.
Repairs
Winter gapping and seasonal movement
Assessment of seasonal gapping to separate normal winter movement — which needs no work at all — from a genuine installation or humidity fault.
When this is the job
Gaps appear between boards every January and close again by June. Toronto's indoor relative humidity swings hard across the year, and most of what this produces is normal. Some of it is not.
Also called: gaps in hardwood floor winter · hardwood floor gaps closing summer · hardwood shrinkage Toronto winter
Published band
From $650 minimum · $18–$35 / sq ft affected
HST extra. A range, not a quote — a firm number follows a moisture reading on site.
Worked example
$5,814 – $8,247
Assessment, 900 sq ft, North York · 1–3 days plus finish cure
Typical specification
- Measure gap width at several points and record the indoor relative humidity with it
- Compare against the species' expected seasonal movement for the board width
- Distinguish uniform gapping (normal) from isolated wide gaps (a fault)
- Humidity management recommended before any carpentry is quoted
Sequence of work
- 1Measure indoor RH and gap width together, in winter.
- 2Compare against expected movement for that species and board width.
- 3If it is within range, say so and recommend humidity control. Quote nothing.
- 4If it is outside range, or isolated, investigate fastening, subfloor moisture or the original acclimation.
What goes wrong
The part of a hardwood job that costs money is rarely the part in the quote. These are the failures that produce a second invoice.
Diagnosing gapping without measuring humidity
A carpentry solution sold for a climate-control problem. The gaps come back the following winter regardless.
Avoided by: Recording RH with every gap measurement. The two numbers only mean something together.
Treating one wide isolated gap as seasonal
A real fault — fastening failure, subfloor moisture, or a board that was never acclimated — is left to get worse.
Avoided by: Distinguishing uniform gapping across the field from an isolated one.
Related
Is this your job?
City, service and size gives you a 2026 GTA band in about twenty seconds. We lock a number only after a moisture reading.