Warmup DCM-PRO Membrane and Heating Cable

By Robert Robillard on Remodeling

Warmup DCM-PRO Uncoupling Mat and Heating Cable

As a remodeling contractor I’m always looking for more efficient, better ways to do our projects.

Recently I came across the Warmup DCM-PRO Membrane and Heating Cable.  The mat is an uncoupling membrane, and the combination of the two gives me a faster way to install radiant heat and subsequent tiles.

I’ve installed Warmup floor heat on many remodeling projects, mostly bathrooms.  On these remodels,  I would have to install a heat mat, then cover the mat with thinset and later return to tile. The DCM-PRO system is WAY faster than using cable spacing strips, it provides anti-fracture protection and it allows you to tile immediately.

The Warmup DCM-PRO Membrane is ¼” thick,is sold as a roll (to cover 150sqft in total) and sheets (box of 10 sheets, to cover 80sqft). It is designed for wood and cement subfloors using any tile adhesive.

The DCM-PRO design rated as an anti-fracture membrane and allows for more adhesive to connect with the cable which helps distribute more even heat.  You can use either modified, unmodified thinset or self-levelling mortars (SLU’s) to allow installation of small format tiles and other floor types such as glue-down wood.

DCM-PRO Membrane Features

  • Under 6mm – 1/4” thick
  • Rated as Anti-Fracture membrane as tested by the TCNA against ASTM 118-12
  • Installs with regular or modified thinsets
  • Ready to tile over
  • Use any adhesives or SLU’s on top for flooring installations
  • Highest heating outputs with DCM-PRO Cable
  • Lowest running costs with 1/4” Warmup Insulation Boards (WSC-0725)
  • Smart operation with 4iE-04 Smart WiFi Thermostat (WSC-0926)

DCM-PRO Heating Cable

The Warmup DCM-PRO Heating Cable is a custom designed cable compatible with all uncoupling membranes such as:

  • Schluter®
  • Prodeso Heat Mat
  • Flextherm FLEXSnap
  • Heatmatrix
  • Warmup DCM-PRO Membrane

Warmup recommend a spacing that produces no more than 15w/sqft of heat input into the floor. That’s basically a 3-inch spacing.

When embedding the cable into the mat studs, ensure that the minimum bending radius of the heater wire is no less than 1-inch.


Follow manufacturers installation recommendations and guidelines.

Check the resistance of the heater before, during, and after installation to ensure that no damage has occurred A tolerance of +/- 5% is allowed

DCM-PRO Heating Cable Features

Operating voltage 120V, 208V or 240V
Thickness 3/16” (4.5mm – +/- 0.2mm)
Output Approx. 4W/lin foot
Construction Multi-stranded, dual wire
Inner insulation ETFE
Outer jacket PVC
Earth braid 85% min copper
Cold lead 10ft (3m) long, 2 core braided

Installing the Membrane

Measure and cut a length of mat to suit your room using a utility knife and/or scissors. It’s super easy to cut.

I recommend dry fitting the mats to the room prior to spreading any thin-set. Try to layout or line up the mats so the wire studs, line up and you have straight wire lines. This doesn’t always happen, but the mats are very forgiving.

The goal is to place the heat cables so that you will get the most efficient cable coverage.

Gluing the mats down is easy too. I suggest first, dry fitting the mat to the room prior to spreading thinset. Try to layout the mat placement so that you will get the most efficient cable coverage.

Apply a layer of polymer- modified thinset to the substrate using a 1/4” notch trowel. Position the mat, fleece side down and embed into the adhesive bed.


Mark out the floor with a permanent marker showing where fixtures and other unheated areas are going to be. A marker is also helpful for marking the mat prior to cutting.

THICKNESS 1/4” (65mm)
SPACING 3 1/2” (90mm) & 4 11/16” (120mm)
SIZE 2’6” x 3’3” (770mm x 985mm) sheet 46’7” x 3’3” (14200mm x 985mm) roll
THICKNESS 3/16” (45mm)
(3 CASTELLATIONS – 3 1/2”)

Installing The Heat Cable

The heating wire embeds in between the mat studs in a serpentine pattern or as needed, to access areas and around objects.

When installing the cable DO NOT cross the cable over another run, over cold tails or the floor sensor. This will cause overheating and will damage the cable. Also do not cut the wire, install under permanent fixtures, or use metal staples on the heating cable.

Secure the cold tail using tabs of electrical tape as necessary. DO NOT tape over the manufactured joint or heating cable. These must be fully embedded within the tile adhesive or leveling compound being laid over.


The DCM-PRO cable has a marker at its midpoint. When you reach it, review your progress up to that point and check that you are correctly spacing the cable, ensuring that you will have covered, at least half, of the heated area needed.

This is a GREAT feature to let you know if you’re on track with your current spacing. It allows you to make changes as needed to finish the project.

Floor Sensor Install

The floor sensor for the Warmup DCM-PRO Membrane and Heating Cable is used for temperature regulation of the floor surface. The end of the probe wire contains a capped sensor that should be centered between two heating cables at least 12” (305mm) into the heated area.

The sensor wire MUST NOT touch or cross over the heating cables.


It may be
necessary to chisel out short channels in the subfloor
to minimize the increased height presented by the cold wire joint and floor sensor probe. Before chiseling the area, ensure that the heating cable, unheated lead and floor probe are protected to avoid damage during chiseling. Place the floor probe into the channels and secure with fixing tape.

Pro Tip:

A router works great for this purpose, but does not always fit against the wall.

Electrical Requirements

The Warmup loose heating cables MUST be connected to the electrical system through a Ground Fault Circuit Interrupter (“GFCI”)

We have our electrician run a “homerun” dedicated ircuit for all our heat mats. The electrician also installs plastic conduit in the wall to separate the cold lead and sensor wires.

Thermal Insulation

The insulation levels of a floor will affect both the performance & running costs of under tile heating. Using the heating cable without thermal insulation can take up to 5 hours to heat a room whereas a system with thermal insulation takes less than an hour.

If the Warmup heating cable is being installed onto a concrete base it is highly recommended that a layer of insulation is used prior to installing the heating cable. The thermal insulation reflects the heat upwards instead of allowing heat to penetrate into the subfloor, greatly improving the warm-up times & running costs.

Click here to read an article and see a video where I install the thermal insulation boards.

Warmup 4iE WiFi Thermostat

Warmup only recommends listed or UL certified programmable thermostats designed for use with underfloor heating to control the Warmup loose heating cables.

We use their The 4iE Smart WiFi thermostat, which learns the heat-up and cool down rates of your home to automatically set the most efficient temperatures, reducing usage by up to 25%.   The 4iE thermostat is simple to set up, intuitive and uses your smartphone as a remote interface.Warmup

Final Thoughts

Radiant heat is an efficient way to heat, and is now a permanent solution in my remodeling tool box. Probably the most attractive advantage the Warmup DCM-PRO Membrane and Heating Cable system is the ease of installation and speed of project completion. The DCM-PRO saves me from multiple return trips to a project, which means, time saved is money earned!

Using the DCM-PRO Membrane and Heating Cable

If you enjoyed this post, make sure you subscribe to my RSS feed!

About the author

Robert Robillard

Carpenter / Remodeler / Editor

Rob Robillard is “The Concord Carpenter” Rob is a builder, general contractor, carpenter, woodworker, and editor of Concord Carpenter and ToolBoxBuzz As a General Contractor and carpenter, Rob owns and operates Concord Carpenter LLC. A full-service remodeling and construction company. Rob is a recognized leader in home building best practices and a source for how-to information for building professionals. On this website, Rob covers all aspects of home construction, building science, home improvement, woodworking, remodeling, and some of the best product and tool reviews. Rob is in charge of our Tool and Product Review series - Concord Carpenter Videos where we post all of our tool reviews and video tutorials. Rob approaches remodeling and building construction with a pragmatic and problem-solving approach. He enjoys using his knowledge and experience to help and educate building professionals as well as DIYers on best practices in the construction and remodeling industry. He's a strong advocate for "raising the bar" in the construction trades and promoting the trades to youth. #BeAMentor #Green2Great Craftsmanship, quality, and pride guide his journey on this channel The Concord Carpenter's motto: "Well done is better than well said!" : Read more about Rob

All posts by Robert »

Not what you're looking for?

Search for more articles here. Enter keywords like roof leak, bookcase, deck, etc to find your topic.

© Copyright 2019 A Concord Carpenter · All Rights Reserved