The finished basement humidity level to aim for is a relative humidity (RH) of 30 to 50%, read on a hygrometer in the rooms that will get the new floor. Natural Resources Canada (NRCan) calls that range ideal for a building, and the National Wood Flooring Association (NWFA) gives 30% to 50% as its usual guide for solid wood floors. The SPC planks from our vinyl plank collection featured below are listed as waterproof, one laminate maker draws a firm line at 65%, and for engineered hardwood the NWFA points you to the manufacturer's own requirements. This guide covers the air in a basement that is already finished: what to measure, where to set the dehumidifier, and which floor suits your readings. Testing the slab is a separate job, explained in our guide to moisture testing concrete subfloors.
Quick answer: humidity targets by floor type
- The room itself: 30 to 50% RH for most of the year. NRCan adds that in winter, when heating in a colder climate, RH should be around 30 to 40% to prevent condensation on windows.
- Engineered hardwood: the NWFA's general rule for solid wood is 30% to 50%, and for factory-finished engineered flooring it says to follow the manufacturer's requirements.
- Laminate: Swiss Krono lists 40 to 65% as optimal for its laminate panels and says they should not go where humidity exceeds 65%.
- SPC vinyl: the three Riche SPC planks below are listed as waterproof, which gives you the widest margin for a damp spell. A dehumidifier still keeps the room itself in range, and it does nothing about water coming up through the slab.
Why a finished basement still runs damp
Finishing a basement helps, but it does not turn it into a main floor. The NWFA's installation guidelines describe a finished basement as one where the walls are normally insulated and the space is heated and cooled like the living area above, which makes it a conditioned space. Unconditioned basements, by contrast, are typically cooler and have higher RH than the rooms upstairs.
Summer is the season to watch. NRCan's basement insulation guide notes that condensation can form on foundation walls in summer when the air is very humid and the foundation is cool. One quick check in spring, before you order, will not show you that.
The NWFA asks installers to test and document the temperature and relative humidity in each room where flooring is being installed. That habit is worth borrowing before you choose a floor, and after it is down.
How to measure basement humidity before you choose a floor
A digital hygrometer that shows RH and temperature is the only tool you need. The goal is a short written log that captures the dampest stretch of the year.
- Put it where the floor will go. Set it at about waist height near the middle of the room, away from the dehumidifier's air outlet, so you read the room rather than the machine.
- Read it twice a day. Morning and evening, note the RH, the temperature and the dehumidifier setting.
- Cover every room. A bedroom, office or storage room that will share the new floor deserves its own readings.
- Keep windows and doors shut while the dehumidifier runs. NRCan advises this so the space is dehumidified as efficiently as possible.
- Log a humid summer spell and the start of heating season. Summer highs decide which floor is safe. Winter readings show whether the room settles into NRCan's 30 to 40% winter range.
Reading your log
The highest humid-weather reading in your log is the one that matters. Match it to the row below.
| Highest reading in your log | What it means for the floor |
|---|---|
| 30 to 50% | Inside NRCan's ideal range and the NWFA's general rule for solid wood. SPC, laminate and engineered hardwood are all on the table. |
| Above 50%, up to 65% | Above NRCan's range and the NWFA's solid-wood rule, but inside Swiss Krono's 40 to 65% optimal band for laminate. Lower the humidistat setting and check the maker's requirements before you consider engineered hardwood; SPC and laminate both fit. |
| Above 65% | Over the limit in Swiss Krono's laminate instructions. Find the moisture source first. Of the three floor types here, only the SPC planks are listed as waterproof. |
Dehumidifier settings that keep the floor in range
According to NRCan, every ENERGY STAR certified dehumidifier includes a built-in humidistat that lets you set the RH level you want in a room. That dial is your main lever, so use it with your log in hand:
- Summer: set the humidistat inside 30 to 50% and check that your hygrometer agrees a day later. If the room still reads high, NRCan's sizing advice is that more humidity calls for a larger capacity unit.
- Winter: NRCan's figure for heating season in a colder climate is around 30 to 40%. Set the humidistat so it is not working to dry a room that already sits there.
- Placement: if the unit lacks top-mounted discharge, NRCan says to keep it away from walls and furniture so air can circulate around it.
- Outside the house: extending eavestrough downspouts away from the foundation and keeping gutters clear are on NRCan's list of ways to cut the moisture a dehumidifier has to remove.
Matching the floor to your humidity readings
These five floors cover all three types, and the last column shows what each asks of your basement air. Price per square foot is the box price divided by the coverage in one box.
| Floor | Type and build | Box price and coverage | Price per sq ft | Humidity note |
|---|---|---|---|---|
| Riche Natural Birch 6mm SPC | SPC, 6mm with attached IXPE pad, 12mil wear layer, click-lock | $62.93 per 23.64 sq ft box | $2.66/sq ft | Listed as waterproof |
| Riche Heavy-Duty 8mm Driftwood Mist | SPC, 8mm with attached EVA pad, 20mil wear layer, click-lock | $59.00 per 16.55 sq ft box | $3.56/sq ft | Listed as waterproof |
| Riche Greige Oak 10mm SPC | SPC, 10mm, 20mil wear layer, EVA pad attached, click-lock | $59.00 per 11.82 sq ft box | $4.99/sq ft | Listed as waterproof |
| Swiss Krono Grey Oak 10mm laminate (MV 803) | Laminate, 10mm, AC5, click-lock | $42.83 per 17.22 sq ft box | $2.49/sq ft | Maker's limit: not where humidity exceeds 65% |
| European Oak Engineered Slate | Engineered oak, 6.5" wide, 2mm oak top layer, wire brushed, nail-down | $95.71 per 20.24 sq ft box | $4.73/sq ft | NWFA solid-wood rule: 30% to 50%; follow the maker's requirements |
Prices checked October 6, 2026. Box prices and coverage come from our current catalogue.
SPC vinyl: the most margin for a damp summer
All three Riche planks in the table are listed as waterproof, and each has a pad attached to the back, so there is no separate underlay roll to sit in a damp room. The product page for Natural Birch describes its core this way: "Stands up to spills, humidity, and moisture in any room of the home." That is why SPC is the straightforward pick for a basement whose log drifts above 50% on humid days.
Choosing between the three comes down to wear and feel rather than humidity. Natural Birch is 6mm thick with a 12mil wear layer, and at $2.66/sq ft it costs less per square foot than the other two SPC planks. Driftwood Mist and Greige Oak both carry a 20mil wear layer, at 8mm and 10mm total thickness, which makes sense for a basement used as a playroom, home gym or rental suite. If the space is a separate unit, our guide to waterproof flooring for basement apartments looks at that use in more depth.
Laminate: fine at or below 65%, a poor bet above it
At $2.49/sq ft, the Swiss Krono Grey Oak costs less per square foot than any of the other four floors, with a 10mm board and an AC5 rating. Swiss Krono's general instructions say its laminate panels are intended for rooms "characterized by a stable climate", that floor panels change their dimensions under the influence of temperature and air humidity changes, and that they should not be installed where humidity exceeds 65%.
That makes laminate a sound basement choice only when your summer log stays at or under 65% with the dehumidifier running, ideally inside the 40 to 65% band Swiss Krono calls optimal. If the readings creep past that on humid days, fix the moisture first or move to SPC.
Engineered hardwood: the maker's range comes first
Our European Oak Engineered Slate is a 6.5" wide, wire-brushed Character Grade board with a 2mm oak top layer, at $4.73/sq ft. As a general rule for solid wood flooring, the NWFA defines suitable conditions as a relative humidity range between 30% to 50%, with geographic exceptions. For factory-finished engineered flooring, its guidelines say the manufacturer's temperature and humidity requirements are the ones to follow.
This board's install method is listed as nail-down, so it is fastened to a wood subfloor rather than floated on the slab. Whether that build-up makes sense in your basement is a subfloor question we look at when we quote. On the humidity side, choose it only if your log shows the room can be held near 30 to 50% and inside whatever range the manufacturer specifies. Our condo flooring guide for Toronto compares engineered hardwood, SPC and laminate over concrete in more detail.
Where humidity control stops helping
A dehumidifier manages the air. It cannot dry a slab that is pushing moisture up from below, stop a foundation leak or undo a flood, and your hygrometer says nothing about the concrete. A basement needs two separate checks:
- Room air: your log, held inside the range for the floor you want.
- The slab: a moisture test before installation (see the slab-testing guide linked above).
For the wider picture, our complete guide to basement flooring in Toronto covers subfloors and costs, and our roundup of flooring for basement renovations compares more SPC options.
Basement humidity questions
What humidity should a finished basement be kept at?
NRCan's general figure for a building is 30 to 50% RH, dropping to around 30 to 40% in winter heating season. If engineered hardwood is going down, check the flooring manufacturer's own range first; for solid wood, the NWFA works to 30% to 50%.
Does vinyl plank flooring need a dehumidifier in a basement?
Not for the planks' sake if you choose one of the three Riche floors above, which are listed as waterproof. The room is another matter: if your readings sit above 50%, running a dehumidifier brings the space back toward NRCan's range whatever floor is underfoot.
Is 60% humidity too high for laminate in a basement?
It is above NRCan's ideal band but still under the 65% ceiling Swiss Krono sets for its laminate. Read it as a cue to turn the humidistat down and keep logging. If summer highs pass 65%, switch your plan to SPC.
How long should I track humidity before ordering a floor?
There is no fixed rule, but the log should include at least one stretch of muggy summer weather, since humid air meeting a cool foundation is the situation NRCan flags for condensation. If you can, carry it into the first weeks of heating season to see the low end as well.
Plan your basement floor with a Toronto quote
Send us your room sizes, a few photos and your hygrometer readings, and we will suggest a floor that suits the conditions you have. You can request a flooring quote or browse the full SPC and vinyl plank range.
Top Floorings Depot
3781 Victoria Park Avenue, Unit 1, Toronto, ON M1W 3K5
www.topfloorings.com
Call: 416-499-0117
Text: 416-770-8819