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Best Basement Flooring in Ontario: Slab Moisture, Cold Feet, Subfloor Panels, Vinyl Plank, Tile, Carpet and What I Put in My Own Basements
Flooring & Tile
The Best Basement Floor Is the One That Survives the Slab Under It: Moisture, Cold, Panels, Plank, Tile and Carpet, Ranked
A basement slab in Ontario is a slice of concrete sitting on cold, damp ground, and in most houses built before about 2010 there is nothing under it but gravel. It stays at 10 to 13 C all year and it breathes water vapour up through itself forever. Any floor you put on it has to live with both. Vinyl plank is the answer for most basements, at about $6.00 a square foot installed plus $0.35 for poly, and the rest of this page is about when it is not, and what goes between it and the concrete.
What the slab is doing
Two things, and they are separate problems. The first is moisture. Concrete is porous and the soil under it is wet, so vapour moves up through the slab toward the dry air of the house. A slab with 6-mil poly under it, which code has required for a long time now, passes very little. A 1975 slab on gravel passes a lot. Tape a 2 ft square of poly to the floor for two days and look under it: if it is beaded or the concrete is dark, that is your slab talking. The proper test is a probe drilled into the concrete, and the numbers are on the vinyl over concrete page.
The second is cold. Ground temperature in Simcoe County at footing depth is about 8 to 10 C, and an uninsulated slab sits a few degrees above that. Every floor laid directly on it feels cold in bare feet, because the floor is cold, not because of the material. Vinyl plank “feels colder” than carpet only because carpet is an insulator and you are standing on the insulation. A heated slab fixes it at the source; the basement radiant heating page covers that, and what it costs is on the hydronic cost page, not here.
The options, ranked for a normal Ontario basement
| Floor | Installed, mid grade | With what under it | Verdict |
|---|---|---|---|
| Vinyl plank (SPC), floating | $6.00 | Taped 6-mil poly, $0.35; or a raised panel subfloor, $3.50 | The default. Waterproof, warm enough, replaceable, cheap. Needs a flat slab and a moisture test. |
| Porcelain tile | $15.75 | Nothing on a sound slab; crack-isolation membrane over cracks | Best over a heated slab, best in a bathroom or laundry, best if it ever floods. Coldest in bare feet on an unheated slab. |
| Carpet and pad | $5.00 | Raised panel subfloor, $3.50, or nothing if you accept the risk | Warmest and quietest, cheapest to buy, and the first thing out the door after a wet spring. A sponge on a damp slab. |
| Engineered hardwood, glued | $12.75 | Epoxy moisture mitigation if the slab tests wet, $4.00 | Possible on a dry slab with the right product, and I have done it over heated slabs. Not for a 1975 basement. |
| Laminate | $5.50 | Taped poly, $0.35 | Allowed by the makers over a dry slab. One floor drain backing up ends it. I do not put it in basements. |
| Solid hardwood | $12.00 | No | Not below grade, by every manufacturer and the NWFA. It cups. |
Prices are per square foot of floor, planks or tile supplied and installed, before removal, levelling, trim and HST. The full price table on the cost hub has every grade.
What goes between the floor and the concrete
Nothing. Tile goes straight onto clean, flat concrete with thinset, and that is the right answer for tile. A slab with cracks gets a crack-isolation membrane over the cracks first, because the crack will move and the tile over it will crack too.
Taped poly, $0.35 a square foot. A 6-mil sheet under a floating vinyl floor, seams taped, run up the wall behind the baseboard. It stops the vapour that gets through the slab from sitting against the plank, and it is what every vinyl manufacturer wants on concrete. Cheap and skipped constantly.
Raised panel subfloor, $3.50 a square foot. DRIcore and the like: 2 ft squares of OSB on a plastic base with channels underneath, so air moves under the floor and the floor itself is 3/4 in. up off the concrete. It makes the basement a degree or two warmer underfoot, gives carpet somewhere to live besides the concrete, and gives a floating floor a flat wood base when the slab is not flat. It costs more than the vinyl plank that goes on it, it takes 7/8 in. of headroom, and water that gets under it has to be found and dried. On a flat, tested slab with vinyl going down, I skip it. Under carpet, or on a slab that fails the poly test, it earns its keep.
Epoxy moisture mitigation, $4.00 a square foot. A two-part coating rolled on a slab that tests too wet for glue-down flooring. It works. It also costs two thirds of a vinyl floor, and on an old slab the question is whether the problem is vapour or water, because a coating does nothing about a wet footing. Why basements leak is the page to read before spending it.
An 800 sq ft basement, three ways
Vinyl plank on poly. Planks 880 sq ft at $3.25 is $2,860. Labour 800 at $2.75 is $2,200. Poly 800 at $0.35 is $280. Four transitions at $35 is $140. Delivery $150. Total $5,630 before HST, $6,362 with. $7.04 a square foot, all in.
Vinyl plank on a raised panel subfloor. The same $5,630 less the poly, $5,350, plus panels 800 at $3.50 is $2,800: $8,150 before HST, $9,210 with. The panels cost half again what the floor did. Worth it on a cold, uneven or doubtful slab; not on a good one.
Porcelain tile, 12×24 straight lay. Tile 896 sq ft with 12% waste at $4.50 is $4,032. Setting materials 800 at $1.25 is $1,000. Setter 800 at $10.00 is $8,000. Delivery $150. Total $13,182 before HST, $14,896 with. Nearly $16.50 a square foot, and the best floor of the three if the slab is heated, because tile hands the heat to the room and plank holds some of it back.
What I put in mine
Every basement I build is an ICF foundation on a slab with insulation and poly under it and hydronic tubing in it. The slab is dry from below and warm from within, which removes both of the problems this page is about. On those slabs I put porcelain in the bathrooms and laundry, and glue-down vinyl plank or glued engineered hardwood everywhere else, directly on the concrete, after the slab has had its months to dry and after I have put a probe in it anyway. The water goes into the tubing at about 40 C and the floor surface runs 30 to 37 C, and the glued plank has been fine on it; the plank sheets cap the surface at 27 to 29 C and the warranty stops there, so above the sheet you are trusting the builder and the product, not the paper. A floating floor over a heated slab can gap at every joint as it warms, so I glue. The heated ICF slab page walks through the sequence, and the slab itself is the business of ICFPro.ca.
If the basement is going to be an apartment, the floor also has to sit on a rated, sound-controlled assembly and that changes the budget more than the flooring does. Basement apartment costs, and for a suite in the yard instead of under the house, GardenSuiteOntario.com.
Questions people ask
What is the best flooring for a basement in Ontario?
Vinyl plank for most of it, porcelain tile in the bathroom and laundry, nothing made of wood fibre anywhere. About $6.00 a square foot installed for the plank, plus $0.35 for poly or $3.50 for a raised subfloor if the slab is cold or uneven.
Do I need a subfloor in my basement?
Not for vinyl plank or tile on a flat, dry slab. Yes under carpet, and yes if the slab is cold, uneven or fails a moisture test and you want a floating floor on it anyway. A raised panel subfloor is $3.50 a square foot installed.
Is carpet a bad idea in a basement?
On a slab that has ever been damp, yes. On a raised subfloor over a tested slab, in a bedroom or a theatre room, it is the warmest and quietest floor you can buy and still the cheapest. Keep it out of the laundry and away from the floor drain.
Why is my basement floor so cold?
Because the slab is at 12 C and nothing is between your foot and it. A raised subfloor helps a little, carpet helps more, and heating the slab fixes it. Basement radiant heating.
Can I put engineered hardwood in a basement?
Over a dry, tested slab, glued down, with a product rated for below grade, yes. Over a slab that fails the test, only after $4.00 a square foot of epoxy, which usually makes vinyl the better buy.
Price your basement
The flooring cost calculator has the poly, the raised subfloor and the moisture mitigation as line items, so you can see what each one does to the total before anyone drills the slab. Quotes in hand? The $99 review tells you which one left the subfloor out.
Sources and further reading
- DRIcore: the raised panel basement subfloor and what it does for a cold, damp slab.
- Addressing moisture and mould in your home: Health Canada: what mould under a floor means, when it can be cleaned and when the floor comes out.
- National Wood Flooring Association: the installation guidelines every hardwood warranty points to: subfloor flatness, moisture limits, acclimation, fastening schedules and the radiant-heat chapter.
