Garages are an underappreciated and overused feature of our homes that many of us take for granted. For the do-it-yourselfer, the garage may be the most used room in the house. Working in a garage in winter can be very uncomfortable, especially in cold climates.
Today, we will discuss one popular garage feature that offers comfortability, usability, and a good return on investment: radiant floor heating.
How Does Garage Radiant Floor Heating Work
Radiant floor heating comes in a few forms, but the most popular by far are the electric and hydronic radiant floor heating systems.
Electric radiant floor heating works by installing heated wires under a floor, or in this case, concrete. This heat radiates upward, warming the concrete and surrounding area.
Hydronic radiant heating employs special tubing, known as PEX, to circulate warm water throughout the pad. This warms the pad evenly, and since heat rises, it can also warm the rest of the garage.
Generally speaking, heated garage floors heat the whole garage. The heat efficiency will depend largely not only on the aforementioned factors like insulation and airtightness but the size of the heating system also. Colder climates will obviously require more heating for longer periods, but the heat radiating from the floor will heat the surrounding air as well.
Radiant floor heating can be installed under virtually any floor covering, but today we will focus on installing a system under a new garage concrete pad.
How Long Does Radiant Heating Take to Heat a Garage Floor?
This depends on a number of factors, like insulation and airtightness. For example, a hydronic system located in a two-car garage with 9’ ceilings can raise the ambient temperature by about five degrees in an hour or two.
However, since garages aren’t typically part of the HVAC system, a radiant floor heating system will work harder than the same system inside the home, so you should set reasonable expectations. The good news is we don’t typically need our garage to be as comfortable as indoors. More often than not, we just need to keep the ambient temperature above freezing to protect items like photographs and paint.
Concrete tends to hold temperature better than wood, so underfloor heating is a great choice for a garage.
Are Heated Garage Floors Safe?
Yes. Radiant floor heating is safe to use, even in areas that may contain flammables. Since the heat source is isolated under concrete, it can never become hot enough to become dangerous. This also means you can paint a concrete floor with radiant floor heating. In terms of fire hazards, radiant floor heating is no more dangerous to use than any other electrical appliance.
Pros and Cons of Radiant Floor Heating in a Garage
How to Install a Heated Garage Floor
As a rule for installing radiant heating systems, garage floors with underfloor heating will use a hydronic system versus an electric system. This is because electric systems typically get more expensive as they become larger, where the opposite is true for hydronic systems. Because concrete pads can get quite large, hydronic systems are used almost exclusively to heat a garage floor.
An underfloor hydronic heating system will have more components than a comparable electric system. Because a hydronic system uses both electricity and water, both plumbing and electrical work will be required. We will assume that the new pad is ready to be poured.
Here is a list of tools you may need:
- Concrete tools, such as a mixing paddle, drill, and trowel
- Utility knife
- Wood and/or masonry chisel
- PEX expander tool
- PEX tubing cutter
- Tape and/or adhesive
- Electrical tools, such as a wire stripper and crimper, screwdriver, and multimeter
Measure the entire garage floor space the system will be installed in. This will be the square footage number you will need to purchase your materials.
Hydronic systems are not typically available in ready-to-use kit form, so a thorough understanding of the system and installation procedure is very important. For example, if you plan to have a vanity-style storage cabinet or workbench on your new heated floor, avoid running tubing to that area.
Heat trapped under cabinetry and other obstacles can be problematic, so avoiding those areas by at least 4” is recommended. The manufacturer of your materials will have specific instructions.
Even professionals will usually involve the manufacturer of their system when calculating the materials needed. These companies have design experts available specifically to reduce costly mistakes.
Hydronic systems can become quite complex, however, manufacturers today have improved the installation process by combining components and reducing the complexity.
For example, a hydroponic system requires a vapor barrier between the ground and the concrete. This is standard for any concrete pad, but 2’ x 4’ panels are now available specifically for hydroponic installations. These panels are insulated on one side, have a vapor barrier built-in, and provide a mechanical connection to the tubing.
Although 6mm roll plastic can be used as a vapor barrier, the most common procedure uses these panels as they eliminate installing the vapor barrier, insulation, and tubing guides separately, saving time and money.
To install these panels, start at the corner of the garage where the connections to electricity and water will be located. Lay down a full panel and snap another panel to it in any direction. These panels work like interlocking toy bricks and eliminate the need for additional reinforcement.
After reaching the opposite wall, cut the next panel in half and start the next row. This will prevent two panels from sharing a joint and will retard future cracking of the concrete. Continue until the entire area is covered with the panels.
One reason PEX tubing is so popular is that it comes in very long rolls, which eliminates most of the joints normally present in standard plumbing pipes. Traditionally, leaks in plumbing will usually occur at a joint, so eliminating most of them makes PEX very reliable and durable.
Starting in the same corner as before, roll out the tubing so it is somewhat straight and begin winding it along with the panels. These panels will usually have guides every 3”-4” apart, which allows for loops of up to 12” in the tubing. This is useful because it allows greater control of the total heat produced by the system.
Loop the tubing from one end of the garage to the other until the end of the roll is reached. In most applications, you can now connect another roll to it using connectors designed for PEX tubing and a PEX expander tool.
Once the end of the pad is reached, a good practice is to run the tubing into a small section of conduit that will extend from the concrete. This will prevent damage to the tubing where it exits the pad.
If for some reason you need to only heat a section of the garage floor, you can create controllable zones using a manifold. This will allow for certain parts of the garage floor to be heated, while others are not.
With both the tubing and electrical runs made, you can connect the system together. Using a PEX expander tool, connect the tubing to the manifold and the manifold to the boiler and pump.
The electrical connections can use either 110v or 220v service, depending on the system requirements. If you are inexperienced working with electricity, hiring a professional to make these connections is recommended.
How Long Does it Take to Install Radiant Floor Heating?
Most hydronic floor heating projects can be installed in a garage over a weekend. However, time requirements will vary depending on the system being used and the size of the pad.
How Warm Should a Heated Garage Floor Be?
As mentioned previously, a garage floor isn’t usually required to be toasty warm. Therefore, many owners will set the thermostat to a temperature a few degrees above freezing. If the garage is well insulated, including the garage door, the garage can be made warm even on a cold day.
How Much Does a Heated Garage Floor Cost
The cost for a garage floor heating system will, of course, vary from region to region, but expect to pay between $8.00-$20.00 USD per square foot. Hydronic systems in a garage are efficient and do not usually operate 24 hours a day, so the operating cost is usually just a few dollars per day.
On average, radiant garage floor heating is cost-effective. Hydronic systems use circulating warm water to warm a floor. They are more cost-effective to operate, but the installation costs are much greater. Installing hydronic radiant heating in garages is usually done when a new pad is being poured, but it can be installed over old concrete with new concrete added on top.
How Long Do Heated Floors Last In a Garage?
Hydronic floor heating uses a pump and boiler, which have a finite lifespan of usually 15-20 years. The tubing, however, will typically last 20-30 years. This is essentially double the lifespan of a similar forced-air system, such as a heat pump. Many owners leave the system on all the time, relying on the thermostat to keep the garage comfortable.
Is Heating My Garage Floor For Me?
If you live in a colder climate and are a do-it-yourselfer, you will likely enjoy a radiant floor system in your garage for years to come. The feature has become so popular that a heated garage floor is expected in many upscale homes. So, depending on where you live, having a heated garage floor can offer a great return on investment while keeping your garage comfortable year-round.