Questions and Answers for R-Matte Rmax Plus-3, 1/2 in. x 4 ft. x 8 ft. R-3.2 Polyisocyanurate Rigid Foam Insulation Board

A:  Probably ... Yes ... but it may not be the best solution. At issue is constant downward pressure. Closed foam board is stiff and will support the weight ... for a time. After a while, the cells will shift and crumble. When that happens, the floor support will dwindle and you will get waffling. Also, if it gets wet, then you will have real trouble. Best to create an underfloor with 2x4's and fill in the spaces with R-Max. Then you will have both strength and insulation.

A:  I would not use this for that purpose. It is not designed for that purpose and lacks the density among other factors.

A:  R-Matte Plus-3 has a nominal compressive strength of 16 psi...this equates to 2,300 psf (pounds per square foot). This means that the insulation board can support up to 2,300 pounds per square foot. The typical design Live Load (LL) for a home is under 50 psf and 200 psf in a garage. Polyiso is a closed-cell rigid foam that does not absorb water into the core of the foam. Once the insulation is placed, it is required that a structural sheathing like plywood be placed over it before installing the flooring. The flooring material needs this subflooring to be able to attach. Further, contact the flooring manufacturer for their requirements for the thickness of the subflooring. Flooring cannot be directly attached to any rigid foam insulation product.

A:  Each store carries different product thicknesses. They can order 2" thickness with a large enough order. Or, alternatively it is acceptable and recommended to install rigid foam polyiso insulation board in staggered layers to obtain the required thickness. Staggering the installation of insulation helps reduce air leakage through the assembly. If you would like more help locating Rmax products, send an email to Rmax@Rmax.com

A:  Yes ... you can go to this website and set up in-store delivery for the stores near you ---> https://www.homedepot.com/p/Thermasheath-Rmax-Thermasheath-3-2-in-x-4-ft-x-8-ft-R-13-1-Polyisocyanurate-Rigid-Foam-Insulation-Board-613010/100573703

A:  Here's the only one we could find in 3/4" thickness ---> https://www.homedepot.com/p/3-4-in-x-1-25-ft-x-4-ft-R-2-65-Polystyrene-Panel-Insulation-Sheathing-6-Pack-150705/202090272

A:  Yes. R-Matte Plus-3 comes in 3/4" thickness. However, each Home Depot location carries specific thicknesses. The customer service desk may be able to order 3/4" if the quantity is sufficient. They may also carry Thermasheath-3 at 3/4". The current community answer provides a link to polystyrene product which is by NO MEANS an equivalent substitute for Polyiso.

A:  I would think so , as 2 X 1/2 inches will make 1 inch ,it would be double. Great insulation, also GREAT SOUND BARIER.

A:  it's foil faced on both sides, one side is just printed. The only issue would be water getting in between the layers and getting stuck. Make sure to seal the edges with foil tape or chalk.

A:  Yes ... but you are making a mistake. A "dead" floor is a result of a solid floor. The "deadest" floor would be a concrete slab ... no vibrations or transmission of sonic energy. Putting 3/4" OSB on a concrete slab and making sure that there are no moving seams or gaps would give you the "deadest" surface. Now, to that, you are suggesting a layer of foam that can compress and then another layer of wood that can "thump" and vibrate. Can you do it? Sure. Will it work ... nope. And over time, it will get worse and worse.

A:  No. this stuff is not structural, and will crush under a load. That half inch will flatten over time, and you'll get squeaky floors.

A:  No, vinyl plank flooring requires a rigid surface such as concrete or plywood. The insulation will crush under the weight of the floor and the traffic crossing it. Use plywood the raise the subfloor level. Mike

A:  Yes ... however, depending on weight and usage, over time this material may weaken and lose some of it's weight bearing capacity. The insulation ability may be compromised, too. Insulation materials, by their very design and nature are not the best at handling download force.

A:  No, it is not.

A:  I don’t know about the best but does a great job of dealing allso great insulation

A:  Eh.... This is rigid foil backed foam, and as such, won't dampen sound very well. You need something denser (regular weight drywall) or something absorbent (open cell foam- acoustic foam), properly installed roll fiberglass works reasonably well too.

A:  The one I bought is just a plain grayish/silver with the "RMAX" on the other side(see photo).

A:  It’s kind of a silver matte on the RMAX side and the reverse side is basically the same finish as aluminum foil so probably not ideal either. Assuming you have stud walls and not a pole barn type garage maybe consider unfaced batt insulation if you won’t be drywalling? Much more R-value

A:  No. Do not use any foam plastic insulations to create a plenum. Foam plastic insulations must be separated from plenums by metal. It is usually acceptable to wrap metal ducts with polyiso.

A:  This may not be the best choice and it will certainly take some engineering knowhow to get it right, but it can work.

A:  Good Morning, generally polyiso rigid foam insulation is of no harm to humans or animals when used as building insulation.

A:  Great insulation,I would think avoid being able to eat it.

A:  Yes, it is safe for insulating a horse barn, however, you need to make sure the horses don't eat it by covering with wood paneling or placing it out of reach.