Heated tile floors used to be a luxury reserved for high-end custom builds. With Schluter® DITRA-HEAT, they're now a weekend project — and one of the highest-impact upgrades you can make to a bathroom, kitchen, or basement.
This guide walks through what DITRA-HEAT is, how it works, how to size a system for your space (we've embedded our cable calculator below), and which thermostat fits your needs. Whether you're a homeowner planning your first heated floor or a tile setter sizing your hundredth, this is the complete reference.
What is Schluter DITRA-HEAT?
DITRA-HEAT is an electric in-floor heating system from Schluter-Systems (Plattsburgh, NY) that combines three jobs into one orange polyethylene membrane: tile uncoupling, vapor management, and heating cable routing. Instead of stapling cables to a plywood overlay and pouring self-leveller over top, you bond DITRA-HEAT to your subfloor with thinset, snap the cable between the membrane's octagonal studs, and tile directly over the whole assembly.
A complete DITRA-HEAT system has three components:
- DITRA-HEAT membrane — the studded orange substrate. Sold by the roll (134.5 sq ft) or by the sheet (8.4 sq ft fill piece).
- DITRA-HEAT-E-HK heating cable — the actual heat source. Comes in 120V or 240V, in fixed lengths matched to specific coverage areas (10.7 sq ft up to 225 sq ft).
- DITRA-HEAT thermostat — controls the temperature. Three tiers: E-R (non-programmable basic), E-RT (touchscreen programmable), and E-RS1 (WiFi + app + voice).
One thermostat controls one cable. If your room needs more than one cable, you need a separate thermostat for each.
How DITRA-HEAT Works — 4 Steps
1. Install the membrane
Apply unmodified thinset to your subfloor with a 11/64" V-notch trowel and press the DITRA-HEAT membrane (fleece-side down) into the wet thinset. Works over concrete, plywood, OSB, or existing tile.
2. Snap in the cable
Lay out your cable routing in advance using a chalk line, then push the DITRA-HEAT-E-HK cable down between the membrane studs at 3" spacing. No clips, no staples, no mesh — the cable snaps in and stays put.
3. Tile right over it
Apply a polymer-modified thinset (like Mapei Ultraflex or Schluter SET) over the cable-loaded membrane with a 1/4" x 3/8" square-notch trowel, then set your tile, stone, or LVT directly on top. The membrane stays in place permanently as your uncoupling and waterproofing layer.
4. Set your thermostat
Connect the cable's cold leads to a DITRA-HEAT thermostat, wire the included floor sensor between the membrane studs at tile level, and you're heating. Most installs use 240V.
Why DITRA-HEAT vs Traditional Electric In-Floor Heat?
Traditional electric floor heating uses heating cables or mats embedded in self-leveller or thinset, then a plywood overlay, then tile. That stack has problems: cracking from substrate movement, moisture trapped under tile, and cables that can't be repaired if damaged during install.
DITRA-HEAT solves all three:
- Uncoupling layer. The orange membrane neutralizes lateral movement between your subfloor and tile. Tiles don't crack even when the subfloor shifts seasonally or over wood joists.
- Vapor-pressure equalization. Air channels under the membrane let moisture escape laterally instead of forcing tiles up.
- Field-repairable cables. A damaged cable can be spliced with the Schluter repair kit and the install continues.
The trade-off: a slightly higher upfront materials cost. The trade-back: no callbacks for cracked grout three years later.
How Much Cable Do You Need?
Cable sizing depends on your heated floor area (not the total room area — subtract anything you don't want to heat, like under the toilet, vanity, or built-in cabinets). Schluter publishes coverage tables for each cable SKU; we've built the math into the calculator below so you don't have to look it up.
Quick reference:
- A standard 5×8 ft bathroom (40 sq ft) with the toilet and vanity subtracted (~12 sq ft) needs about 28 sq ft of heated area — typically a single DHEHK24027 (240V, 27 sq ft) cable.
- A 10×12 ft kitchen with appliances and cabinets subtracted (~70 sq ft heated) usually fits a single DHEHK24075 cable.
- Large open areas above ~134 sq ft must use 240V — that's the 120V catalogue maximum.
Use the calculator at the bottom of this article to enter your room dimensions, pick a voltage, and get the exact cable SKU(s) you need. Multiple cables required for your area? The calculator handles that too, and you can add the full kit to your cart with one click.
120V vs 240V — Which Do You Need?
The voltage decision usually comes down to area and electrical code.
120V connects to a standard 15A household circuit with no special wiring. It's suitable for areas up to ~134 sq ft heated. Good for a single bathroom or a half-bath. Not permitted in Quebec — Quebec electrical code requires 240V for all in-floor heating regardless of room size.
240V needs a dedicated 240V circuit (similar to an electric dryer outlet). Draws half the amperage of an equivalent 120V cable, runs longer, and is required for any heated area above ~134 sq ft. Required throughout Quebec.
If you're unsure which voltage your circuit can support, ask a licensed electrician before purchasing. Cables and thermostats are not interchangeable across voltages.
Choosing Your Thermostat
All three DITRA-HEAT thermostats support both 120V and 240V cables, include built-in Class A GFCI ground-fault protection, work with the included floor sensor, and carry a 3-year manufacturer's warranty. The difference is the user interface and connectivity. The full comparison chart is shown below this section.
What Does a DITRA-HEAT System Cost?
Materials cost per square foot of heated floor (mid-2026 Canadian pricing, before sales tax) typically lands around:
- DITRA-HEAT membrane: ~$3.50/sq ft
- 240V heating cable: ~$6 to $9/sq ft depending on cable size (smaller cables cost more per sq ft)
- Thermostat: one-time cost of $200 (E-R) to $370 (E-RS1)
- Thinset (membrane bond + tile bond): ~$0.50/sq ft
A typical 5×8 ft bathroom (40 sq ft total, ~28 sq ft heated) comes to roughly $450 in materials with an E-R thermostat, or $620 with an E-RS1 smart thermostat. Larger areas have better per-sq-ft economics because the thermostat cost amortizes across more square footage.
Operating cost for the heating itself: DITRA-HEAT puts out 12 watts per sq ft. At Canadian average electricity rates (~$0.13/kWh) and 4 hours of daily use, that's about $0.06 per sq ft per day, or roughly $5/month for a heated bathroom floor used during shower hours.
Frequently Asked Questions
Can DITRA-HEAT go under engineered hardwood or LVT?
Under LVT, yes — the manufacturer must approve the floor for radiant heat (most modern click-LVT does, up to 82°F / 28°C surface temperature). Under engineered hardwood, generally no — the surface temperature limit (~80°F) and uneven heat distribution under wood planks make it a poor fit. For heated wood floors, hydronic systems are a better choice.
Does DITRA-HEAT need to cover the whole floor?
No. You can heat just the high-traffic zones — in front of the vanity and shower in a bathroom, for example — and use a plain DITRA membrane (no cable) for the rest of the floor. The thickness matches so the tile sits level.
Can I install DITRA-HEAT myself?
The membrane and cable install is well within DIY territory — the system was designed to be installer-friendly. The electrical hookup at the thermostat must be done by a licensed electrician per Canadian Electrical Code (typically a dedicated 15A circuit for 120V, or 20A for 240V).
How long does DITRA-HEAT last?
The membrane has no moving parts and is rated for the life of the floor. The heating cable carries a 10-year manufacturer warranty; in practice, properly-installed cables routinely last 20+ years. The thermostat carries a 3-year warranty.
What if the cable gets damaged during install?
Use the Schluter DITRA-HEAT repair kit to splice the damaged section and continue. Don't ohm-test from inside the kit — Schluter's instructions are explicit on the sequence.
Ready to Get Started?
Use the cable sizing calculator below to find the right kit for your project. The calculator picks the smallest cable (or combination of cables) that covers your heated area, factors in voltage requirements, and lets you add the full set to your cart in one click.
Need help with the membrane sizing or want a quote on a full system? Contact our team — we ship Schluter DITRA-HEAT Canada-wide and can usually have your kit out the same day.
