Concrete Slab Insulation
Installing under slab insulation before the concrete is poured is very simple. The necessary steps are as follows:
• Finished height of ceiling: Know where the finished height of the concrete slab needs to be, and make sure you don’t back fill too much. It is crucial to have enough depth for the moisture-resistant insulation you are going to use.
• Grading: Ensure the gravel or sand is as flat as possible. The insulation follows the contour of the ground. The more level the ground and even the concrete slab, the stronger the concrete slab will be.
• Area to insulate: Calculate how much surface area you need to cover by measuring length multiplied by width.
• Moisture barrier: Although seams could be taped, it is always best practice to lay a moisture barrier under your insulation. A moisture barrier under the insulation will help control gasses from coming through the concrete floor.
• Insulation placement: Place the sheets of rigid insulation under the entire area to be covered by concrete.
You only have one chance to install the concrete slab properly without jack hammering out the floor. As such, be sure to follow the installation instructions provided to you when purchasing INSTA-PANELS®. Generally, it will take about a day to install INSTA-PANELS® properly.
Heat moves from hot to cold. If you insulate all areas in your home with high R-value materials but fail to insulate the underside of your concrete floors, heat will escape through the ground. Many people don’t think about it, but heat in your home does heat walls, floors, and furnishings. This is why it is sensible to insulate the underside of floors. It prevents heat loss. If you are constructing a new home or building, seriously consider insulating the underside of the concrete you are pouring.
Although the Ontario Building Code (OBC) does not require insulation to be installed under non-heated floors in garages, basements, or other rooms, the OBC does require insulation to be installed under heated floor systems. It is, however, best practice to insulate and isolate the entire building envelope. The entire building envelope includes the ground.
The OBC requires R10 be installed under radiant heating systems; therefore, it is safe to consider installing R10 insulation under any concrete floor.
There are a few benefits of installing insulation to the ground before installing concrete over top.
• Concrete slabs stay dry: Ambient temperatures and moisture are more readily controlled, which stops floors from sweating. Dry floors mean easy cleaning and control of bacteria and mold.
• Energy savings: Building codes have for the longest time focused on increasing the thermal efficiency of walls, attics, roofs, doors, and windows but have neglected to take into account that the more insulation is put in one area, the greater the heat loss is in another area. Heat moves from hot to cold; the greater the delta between the heated area and non-heated area, the more the heat flows to where it is cold. Typical non-insulated slabs take the heat from the building and radiate that heat into the ground. By simply insulating the area under the concrete floor, the concrete floor becomes warmer as it slows down the heat from going into the ground.
• Heating is more even: Think of your floor as a radiator. Once the slab is warm, it helps even the overall temperature of the building.
• Healthy home environment: Moisture-resistant floors are more likely to stay free from dust accumulation than damp floors, which further improves the health of the living space.
Under slab or under concrete insulation are composed of low permeation materials and therefore resist moisture. Because our under slab insulation for concrete floors will resist moisture, the room in which the floor insulation is installed will be comfortably dry. This is why INSTA-PANELS® are great in garages, basements, and lived-in areas. Please note, it is best practice to ensure the area under the slab can drain and move moisture away from the insulation and concrete slab.
Insta Panels
In the Ontario Building Code (OBC), steel mesh is not listed as a requirement in basement floor insulation; however, mesh may be a requirement for specific projects. As such, please review your current plans and engineer specifications to ensure you are following the best process for your project.
One of the advantages of using INSTA-PANELS® in a basement is you can staple radiant tubing directly onto the panel and therefore don’t need any expensive or laborious add-ons for the radiant tubing. Both our fiberglass and steel-lined panels can be stapled; however, it is easier to staple tubing onto the fiberglass product.
The OBC dictates 4″ of 25MPA concrete for a basement slab. Many people try to make slabs thinner so they gain head room as well as reduce the amount of money they spend on concrete; however, pours that are less than four inches tend to crack more readily. Pouring over INSTA-PANELS® is no different than pouring over gravel as far as strength goes, providing all else is equal. A four-inch pour is always best.
Installing concrete over INSTA-PANELS® is easy. INSTA-PANELS® will not crack when walked on and will require no additional protection if you are using a wheelbarrow. Concrete buggies are also used for placing concrete on INSTA-PANELS®. Although it has been done, we do not recommend driving on INSTA-PANELS® with a concrete truck.
INSTA-PANELS® are typically 1 3/4″ thick and are R11 for the 20” x 64” and 22” x 64” sizes.
INSTA-PANELS® below grade/under slab insulation/radiant floor insulation are used across Ontario on a daily basis. INSTA-PANELS® now have a CCMC report and are evaluated to meet government standards and the building code for insulation for below grade/basement concrete or under slabs. E-mail or call our office if you would like a technical data sheet on INSTA-PANELS® sent to you.
There is minimal difference between metal and fiberglass skinned panels other than the skins are 26 gauge metal and 1/16″ of high density fiberglass. Clips for hydronic radiant floor heating systems can be fastened to both metal and fiberglass with screws and staples, saving on installing costly metal mesh that tubes are tied to by zippy ties.
INSTA-PANELS® are easy to install. Panels come in predominantly 20″ x 64” and 22″ x 64″ and are shipped in skids of 50 pieces. INSTA-PANELS® can be installed on gravel or most dirt floors. It is recommended to maintain a smooth, even surface so that the INSTA-PANELS® don’t shift. This is the same for all board insulation products.
INSTA-PANELS® can be installed by anyone. Depending on how the job is orchestrated, it is not uncommon for the home owner to install their own insulation prior to the radiant tubes going in. INSTA-PANELS® radiant floor insulation is used and installed by plumbers, heating and cooling (HVAC) contractors, and general contractors alike.
INSTA-PANELS® are fairly easy to cut; however, the tool you should use to cut the panel depends on whether the panel is metal or fiberglass skinned. Electric, circular, and gas cut off saws are the tools of choice when cutting INSTA-PANELS®; however, you shouldn’t need to do much cutting.
There are many job sites in Ontario that are using INSTA-PANELS® as the insulation of choice for radiant floor applications and non-heated floors. If you would like to see our product, please contact us to find a location near you. We can also have an insulation sample sent to you. In the mean time, check out our INSTA-PANELS® board insulation video and see how easy they are to use.
Radiant Floor Heating
Some applications of radiant floor heating require more insulation than others and some may not require any. If the radiant floor system that you are installing or having installed is part of the building envelope, like a basement concrete floor or garage concrete floor, then it is imperative that the proper amount of insulation is installed so that the radiant floor system can function efficiently.
In the southwestern region of Ontario, Canada, the Ontario Building Code (OBC) requires R10 insulation to be installed with radiant floor heat systems. The rate at which heat moves out of a building depends on a couple of variables. The first variable is the delta between the inside and outside temperature, and the second variable is how well the rest of the structure is insulated. Many professionals agree that the more insulation you have in the building, including walls and ceilings, the more you should put in the ground. After all, the ground is a part of the building envelope.
Many people will install more than the standard R10 in an effort to isolate the ground from the radiant heat source, forcing more heat upwards. Remember, hot air may rise, but heat moves from hot to cold; therefore, the more you insulate the rest of your home or commercial building, the more heat you force to the lesser insulated areas, which typically include windows and concrete slabs. The more insulation you put under the floor slab, the less heat goes into the ground.
If radiant heating is installed on a floor system that has leaving space below it, the insulation is not as critical, but it still is a good idea to isolate it as best as possible so you can maintain effective zoning. Insulating these radiant floor areas may also help with sound and acoustics.
There are primarily two types of radiant floor heating that can be installed into concrete: electric and hydronic.
Electric Radiant Floor Heating
Electric radiant floor heating is mainly used for small areas and in retro fit construction applications. Electric radiant is installed via electric cables and mats and typically controlled in the zone it is installed. It works well in conjunction with a forced air system that is found in many Canadian homes. Electrically heated floors are usually used for comfort purposes and are common in wood floor structures under tile floors and a good floor warmer. The downside to electric radiant floors is they typically cost more to operate than hydronic systems.
Hydronic Radiant Floor Heating
Hydronic radiant floor heating systems use a water heater or boiler and a pump system that move water through a network of tubes through the flooring system. Hydronic water heating helps the building maintain an even heat and virtually eliminates the hot and cold cycling and drafts a forced air system can create. Large heated concrete slabs become large comfortable masses of heat evenly distributing warmth to the occupants above or below. Hydronic water heat is cheaper to operate than its electrical radiant floor equivalent.
There are many variables to how efficient a radiant floor heating system is and how it will compare to a forced air heating system. The main thing we need to keep in mind is it takes a certain amount of BTUs to heat a space and how efficiently you can make that BTU will determine the overall efficiency. Large hydronically heated concrete floor slabs maintain an even temperature and can often be operated at lower temperatures and maintain the same comfort as a forced air heating system at a higher temperature because it does not cycle in the same way.
The key ingredient to a comfortable and successful building is insulation and air tightness. Buildings that are insulated and air sealed properly always function more efficiently than a building that is not insulated and air sealed properly. If a hydronically heated floor system is installed in a poorly insulated building, the heating system will not be efficient. If you install a forced air system in a well-insulated building that has the floor slab insulated with rigid foam insulation or INSTA-PANELS®, the building will be comfortable and efficient.
Do not focus on the radiant floor heating system only. Also pay attention to the overall insulation of the entire building. Use higher performance insulation products, such as two pound closed cell spray foam, rigid foam board insulation, and INSTA-PANELS® floor insulation to achieve better results.
The more foam insulation board or other moisture-resistant insulation material under a concrete floor slab, the more efficient the building becomes. This is no different with a hydronic heating system. The more rigid moisture-resistant the insulation, the more efficient the heating system becomes; however, this does not necessarily mean you need less radiant heat tubing. The system needs to be engineered and, in order to ensure the heat dissipates evenly, a certain amount of radiant heat tubing is required.
Size of tubing is also important when calculating the length of radiant heat tubing required. A ½ inch tube cannot supply the same volume of heat as a ¾ inch tube; therefore, it is always important to make sure the hydronic or electric radiant floor heating system is properly engineered, insulated, and installed.
Spacing of hydronic tubes is dependent on a few variables, including wall R-value, window quantity, and roof or attic insulation. Consult with your radiant floor designer or engineer to determine your radiant floor requirements. It is always important to follow manufacturer’s guidelines and best practices, such as making sure there is enough heat reaching areas more susceptible to heat loss; for example, more radiant tubing will need to be installed under windows because windows are particularly vulnerable to heat loss. Windows do not provide the same thermal resistance as a properly insulated wall. As such, heat from the radiant floor is critical in helping create convection currents to move moisture and dry out stagnant air around windows.
The thickness of concrete is dependent on what the building code or the designer dictates. A thicker slab takes longer to warm up than a thinner slab, but it also takes the thicker slab more time to cool down. It is best practice to not install normal concrete less than three-inches thick. Thinner pours can be done on top of radiant floor heating systems. Check building plans for what is required by code. Pouring a thin set concrete or gypsum in conjunction with a radiant floor heating system is possible.
The placement of the radiant tubing does not affect the performance or comfort in a typical four-inch basement concrete pour. Once the slab is warm, it is easy to maintain that heat. It is common practice to raise the radiant tubing in larger and thicker concrete pours (i.e., six inch and greater).
When installing snow melt hydronic for sidewalks and driveways, it is critical to have the tubing near the top as the temperature of the glycol (not water in case it freezes) hovers around freezing so it doesn’t take as long to heat up to start melting the snow. The radiant tubes only need to go above freezing for short periods of time as its only being used to melt the snow, not heat the atmosphere. It is still very important to insulate under the concrete so that the heat from the tubes focuses on melting the snow and not warming the ground. It is best to follow radiant heat manufacturer install instructions in any hydronic heat application.
There are various ways to install tubing in hydronic radiant heat applications. Hydronic tubing can be installed directly to plywood floors using a clip system or stapled directly to the plywood in conjunction with a gypsum over pour. If installing a radiant heating floor system to a concrete slab, it is critical to have the proper insulation underneath the floor heating system.
Hydronic tubing can be installed directly onto INSTA-PANELS® using staples as the fiberglass skin holds the staples. As such, the tubing is installed easily and efficiently. A specialized clip system can also be installed onto INSTA-PANELS®. Once the clip system is installed, the hydronic tubing can be installed quickly. Staples and clips are common fastening methods in homes where radiant tubing is installed onto under slab concrete floors; however, wire mesh is usually required for radiant floor heating systems in a garage, shop, or engineered slab.
Concrete floor slabs in shops and garages typically carry heavier loads, which is why these concrete slabs typically get reinforced with wire mesh. The hydronic heating tubing can be fastened directly onto the wire mesh with zip ties, wire ties, or specialized tie systems with an automated tool.
The benefit of systems without wire mesh is that you save on the wire mesh cost and the labour associated with installing it. The benefit of wire mesh is it could be easier to raise the floor heating system in the radiant slab. Not all concrete slabs require wire mesh. There are fiberglass mesh reinforced concrete systems that work well in conjunction with heated floor slabs. Consult with a radiant floor heat specialist for the best option to fit your heated floor requirements and budget. It is always best to follow the hydronic radiant heat manufacturer guidelines and recommendations.
Installing the radiant tubing in the concrete slab is the most important step in the radiant floor heating process because it is difficult to fix a bad install once the concrete is in place. There are various tubing sizes used to create warm radiant floors. Slab size, tube spacing, heating demands, and under floor insulation are all factors that are taken into account to create a warm slab.
When a hydronic heating engineer calculates the heat load of the building, they will specify the size of tubing and length of loops from the header of the floor heating system. Larger hydronic tubing carries more heat and with potentially less resistance. By undersizing tubes or making loops too long, there is a greater possibility of cold spots in the hydronically heated floor. The tubes will release the heat in the area closest to the header and the loop coming back will be cooler. Not only will the building be cooler in certain areas but the boiler or floor heating system will not operate as efficiently as it needs to reheat the liquid from a lower temperature. It is crucial the installer of the hydronic floor heating system follows the manufacturer’s install specifications.
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis Radiant floors function most effectively with solid surface flooring. Tiles, concrete, and vinyl all work well in conjunction with a heated floor. Hardwood and laminate are also better than carpet. Flooring that does not have a resistance to thermal conductivity are the best materials to put over top of a floor heating system.