Amdry Insulated Subflooring: This product has the highest insulation R-values, between R5 and R7. These insulated subfloor panels can be used with almost every type of top flooring, including engineered or solid hardwood, laminate, carpet, vinyl, and tile.
Carpet, particularly wool and shag varieties, provides the best R-values among all standard flooring choices.
DRICORE Insul-Armor is the most premium subfloor. With an R-value of 4.1, DRICORE Insul-Armor provides one of the highest R-values in the market, meaning maximum warmth and comfort for your family.
Rigid Foam (EPS and XPS)
Expanded polystyrene (EPS) and extruded polystyrene (XPS) are widely used for underfloor insulation due to their moisture resistance and compressive strength. They are particularly well-suited for subfloor installations in homes with concrete or wood bases.
Amdry Insulated Subflooring: This product has the highest insulation R-values, between R5 and R7. These insulated subfloor panels can be used with almost every type of top flooring, including engineered or solid hardwood, laminate, carpet, vinyl, and tile.
To achieve this standard, you will normally need at least 70mm of high-performance foam insulation, or 150mm of mineral wool, but this will vary depending on floor type, shape and size. If you are replacing at least half of a floor then you have to insulate to these standards whether you planned to or not.
The same goes for subflooring. Plywood has a lower R-value (1.1 per inch) than OSB (1.4 per inch). So, while structurally you may be able to get away with thinner plywood, it will have a lower insulating quality than OSB of the same thickness.
Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch.
DRICORE R+ contains all the benefits of the DRICORE Subfloor panel, but with 2x the insulating strength. Designed with a layer of extruded polystyrene foam (XPS), DRICORE R+ delivers an R-value of 2.7.
Thermablok® Aerogel is a revolutionary advancement in thermal technology offering the thinnest insulation available to prevent thermal and cold bridging. Classed as a Super Insulation, Aerogel has the highest insulation value of any known material with the lowest thermal conductivity value of any solid (0.015W/mK).
Designed with Air Gap Technology, DRICORE® Subfloor raises finished floors off the concrete, to not only help protect against moisture, but to also help insulate and cushion against the cold, hard concrete. Helps Protect Against Moisture, Mold, Mildew and Small Water Leaks.
Polyisocyanurate: Known as polyiso for short, polyisocyanurate foam has the highest R-value per inch (R-6.5 to R-6.8) of any rigid insulation. This type of rigid foam usually comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier.
And we have three-quarter inch plywood and this plywood's R-value is also given as . 94, this is for 3/4". Whereas the fiberglass, each inch has an R-value of 3.7.
Vinyl tiles are good for warmth as they are made up of multiple levels of material, making them good insulators. Just like wood flooring, most vinyl flooring is compatible with underfloor heating too. So keeping your home warm really isn't a problem with vinyl flooring.
For proper subfloor insulation, we recommend using R30 whenever possible. If the joist cavities are too shallow, we will use the highest R-value that fits to ensure effective insulation.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space. While you might think that too much insulation can't be bad, there are some significant consequences to consider.
Key Differences: Thermal Resistance: R-21 polyiso boards offer higher thermal resistance compared to R-19, which makes them more effective at reducing heat transfer in colder climates. Thickness: Both R-19 and R-21 polyiso boards are compact by offering high R-values per inch.
Strength and Stability: OSB offers good strength and dimensional stability, suitable for supporting flooring materials. Durability: While durable, OSB may not be as resistant to impact as plywood, and heavy loads can cause indentation or damage.
1. CDX. CDX plywood is the most common plywood used for subflooring. It is usually more affordable because it is rougher and has more imperfections than other types of plywood.
The number used for the R-value of the 7/16” OSB is . 55. This data is from the APA.
Plywood. Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.
For warm climates, the U.S. Department of Energy suggests using R-11 (3½”) insulation under floors, while in cold climates, they recommend R-25 (6″ to 8″) insulation. This practical advice helps ensure energy efficiency and optimal comfort in your home.
Closer joists (16 inches apart) can use thinner subfloors (1/2 inch), but wider spacing in older homes may require thicker materials (7/8 inch plywood or 1 inch OSB). Proper thickness of subfloor ensures floor stability and comfort.