Aug 03, 2025 - 07:42 AM
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We’ve provided several answers to questions related to 136581 , see some other helpful Q&A related to this product.
Question: how do i order this?
Answer: You can enquire about Polyiso Foam Board via the "Request a Quote" form on the product page, or by calling an Eco Advisor at 888-727-2101.
Question: What is the thickness of the 4" board?
Answer: The 4 inch iso board has a thickness of 4 inches. This thickness provides substantial insulation for walls and roofs, helping to lower energy bills and improve comfort.
Question: Should I wrap it in foil before installation?
Answer: It does not need foil wrapped.
Question: Why can't polyiso be used under concrete?
Answer: Polyiso insulation is porous and can absorb moisture from the soil which could reduce the R-value and eventually degrade the foam. Use XPS or EPS closed cell foam for below concrete slabs as they will not absorb moisture.
Question: Can it be shipped to IL?
Answer: Yes, we ship nationwide. Please call in with your shipping address and quantities and we can work up an estimate.
Question: What type of damaged do these polyiso panels have, holes, cracks, scratches, etc????
Answer: 90% of what we offer is factory seconds which are not damaged. The items labeled as damaged only have a few dents or scratches which are inconsequential. When you call in for a quote, ask for a photo.
Question: Where are you located?
Answer: We are located in Fairfield, Iowa.
Question: Closed cell or open?
Answer: Closed cell. Not for use under concrete
Question: Would this be ok to use as insulation between the floor joists under a mobile home?
Answer: Yes, you would want to put a 6mil black plastic vapor barrier on as well.
Question: Hi! My sister is renting a home. How do u apply foam board? Can it be removed when she moves?
Answer: The Polyiso Boards would normally be put into the walls between the studs for the insulation. They can would usually be adhered by adhesive or nail/screws. With the Nail/ xxxx attachment you could in theory remove the boards and take them, with the adhesive that would not be an option. I don't think that these would work for your sisters situation. With that being said it would really depend on a couple factors: 1) Where she is trying to use them in the home2) How much ability to change things in the rental.This is just a basic overview/possible uses. If you would like to email me directly with more details of the situation I can see if there is an option for these to work or not. My email: jeremiah@greenbuildingsupply.com
Question: do you ship to ft lauderdale florida?
Answer: We can, the shipping cost on this product is relatively expensive due to the amount of trailer space it takes up. If you are interested in a quote you can send an email to : jeremiah@greenbuildingsupply.com Please include the following information: Thickness - ( 1" - 4" )Size - 4 x 4 or 4 x 8 Name Address, City, State, and Zip Code Email address ( to send the quote to) Phone number
Question: Does this insulation works in chicago WEATHER?
Answer: Not sure what you mean by Chicago Weather, but this product would work in almost any weather type as long as it is used the way it's designed to be used. This product isn't designed for under concrete. It's designed for interior use on Walls or in between roof joists. Also as a heads up the shipping cost on this product is relatively expensive as this takes up a lot of space on a trailer. If you would like a quote on the product and shipping cost you can send an email to jeremiah@greenbuildingsupply.com with the following information:Thickness ( 1" - 4" ) Size ( 4 x 4 or 4 x 8 )Address, City, State, and Zip Code
Question: Do you ship to Mississippi?
Answer: Yes, however the cost of shipping that distance is generally prohibitive.
Question: Have Palram 83% light transmission corrugated panels over our patio. When ambient temps reach 90?� the under patio temp is 110?�. Will this product reduce that heat load to something bearable? (@100?�, it gets to 120+.)
Answer: This product would reduce the heat underneath, the main issue is that this product has to be mixed with 5 gallons of exterior paint which is going to not let any light through which would defeat the purpose of the 83% light transmission.
Question: What do I need to do to my airless in order to spray my paint with this product in it and any specific tip size is needed it?
Answer: Please review the installation guidelines as it spells out in more detail what is required: https://www.greenbuildingsupply.com/c...
Question: what is best way to apply. spray, roll, or brush?
Answer: Per the Specs at the bottom of the page, "Application Method brush, roller, spray ". Which means you can use whichever of these methods you are most comfortable with.
Question: I have a metal shed. It gets very hot in the summer. I use radiant heat in the winter. Would there be any benefit to painting both the interior and exterior surfaces of walls and roof?
Answer: You would only need to use Radiosity on one side or the other. It does not matter which, however, we would recommend the outside as that is where the intensity of infrared heat is the greatest. If you want to apply to both sides, there is no harm.
Question: Can you paint over with paint and still get benefits?
Answer: Radiosity 3000 is a paint additive that creates a radiant heat barrier on roofs, ceilings, and walls to reduce cooling costs. Easy-to-use - mix product with five gallons of exterior latex or acrylic paint and apply as any paint. So you mix it in the paint. Mixing Instructions : https://www.greenbuildingsupply.com/c...
Question: I need help with reducing summer heat inside but live in a condo. How can I apply this if I have siding and a shingled roof?
Answer: Radiosity 3000 is a paint additive that can be mixed into exterior latex or acrylic paint. If your Condo Association will allow you to paint the siding and roof of your unit, please give us a call (or have your contractor give us a call) and we'd be happy to answer all other questions specific to your project.
Question: Can this product be used on applications that call for 100% acrylic paint? I want to use on exterior pre-primed Hardie board (cement fiber), which requires 100% acrylic paint.
Answer: Per the Features and Benefits section on the product page, "Easy-to-use - mix product with five gallons of exterior latex or acrylic paint and apply as any paint ".
Question: Can I paint this on the outside of my house directly, or do I need to mix it with an exterior paint?
Answer: You need to follow the application instructions: https://www.greenbuildingsupply.com/c...This is a paint additive (mix the product with five gallons of exterior latex or acrylic paint and apply as any paint)
Question: How well does it reflect heat from walls outside inside, when painting inside walls.?
Answer: Radiosity 3000 reflects infrared radiant energy in two ways: outdoors it reflects infrared energy from the sun rather than absorbing it, and indoors it reflects infrared energy back into the home from wood stoves, fireplaces, and hydronic or electric radiant-heated floors.In general, radiant heat barriers reduce heating and cooling loads by about 20%. However, it's important to note that actual savings from reduced cooling or heating will vary depending on the heating/cooling systems of a home, as well as how and where the heat barrier is applied.
Question: If properly formulated paint is "pigmented" with Barium Sulfide NOT Titanium Oxide it will reflect high energy infrared light, like snow which is white reflecting nearly all the light that hits it. See the youtube "Tech Ingredients" where a professor makes Barium Sulfide paint and demonstrates that it will stay cool even in the sun, if properly shielded from low energy ambient infrared will cool below ambient temps. Do you guys know if "Cool Coat" paint works like this? This may be like this but just on a Macro scale, where Barium Sulfide forms microscopic balls that do the reflecting. Are these glass balls all different sizes? because they would need to be to be more effectively layered into a dense layer to allow for proper reflection.
Answer: Our Radiosity is a paint additive made of very very very fine powder consisting of tiny particles of silica glass spheres. One gallon of Radiosity 3000 is added to a 5-gal pail of exterior paint (satin, semi-gloss or gloss sheen). If using indoors, use 5 gal of interior paint. BTW be careful not to breathe or ingest Barrium Sulfide as it is hazardous to your health.
Question: How much does it cool below ambient temperature when in direct sunlight?
Answer: Good question but impossible to answer as there are too many factors involved in ambient temperature. It is well known and documented that radiant heat barriers work to significantly block the Infrared heat of the sun. Our customers say it helps cool their roof or hold heat in their room if used indoors to block radiant heat from a wood stove from escaping. For more information about radiant barriers: https://en.wikipedia.org/wiki/Radiant...
Question: Does Radiosity 3000 work better with one kind of paint vs another; semi-gloss vs flat?Also, does the color of paint make a difference; light vs dark.
Answer: Semi-gloss is preferred but not required. If on the outside, then light colored paint makes more sense. If underneath or inside the roof or wall, then it does not matter.
Question: Can i use this on the exterior of a propane tank?
Answer: If the paint will adhere, then adding this to the paint will work.
Question: If we apply to inside rafter in garage will that work or is it supposed to be applied outside only? We have insulation going in and want to get this applied first if it is the way to do it?
Answer: Radiosity reflects infrared heat, so if your goal is to retain heat inside the garage then you could apply to the rafters and ceiling. If you are trying to keep some of the heat of the sun from entering your garage, you would paint the exterior, ideally beneath your roofing tiles.
Question: Is there an r-rating on this product?
Answer: There is no 'R' Value when dealing with radiant barriers like this one.
Question: Will your product help keep heat out of a closed porch with no insulation in the walls? We cannot use porch in summer - the porch is too hot. If so, will your product work if I apply it to the interior walls only?
Answer: When applied to the exterior walls, yes, it will keep much of the heat out. Applying it to the interior will trap heat, keeping it warmer in the winter. Please consult the mixing and application instructions on our website.
Question: Can I Apply it to my pool deck so it doesn't burn the bottom of my feet?
Answer: Nope. Radiosity 3000 will reflect the infra red rays of the sun. The concrete underneath the surface will not be able to absorb the suns rays, but the surface may still be very hot where it is reflected. It was a good thought. We don't know of anything that will keep the surface cool.
Question: I have a problem with a dark tar and gravel roof that doesn't leak, it just gets full sun and makes an incredibly hot attic (over 100 degrees) and huge summer AC bills. The attic has unpainted rafter boards. Can I apply this with some semi-gloss paint to the exterior on top of the tar and gravel? Secondly, I saw you advise another person to apply the paint inside the attic. Can I also spray the unpainted wood rafters on the underside of the roof to get more protection?
Answer: Application on the outside may or may not adhere well and may eventually wear off. Application on the inside is recommended and will provide almost the same results without the eventual wearing. Yes, spray on the roof deck as well as rafters. No problem.
Question: Where is the ideal application location if trying to keep home cooler in summer?
Answer: You will want to do an exterior application. use Radiosity on any paintable surface; inside your attic, exterior walls, or underneath wall or roofing shingles.
Question: can I add this to Hemp Oil ? On the outside of wood structure?
Answer: No.
Question: Can this be applied with exterior wood stain?
Answer: Absolutely not, this is a paint (only) additive. It will not work in stain.
Question: Would this be okay on top on my van roof? I'm guessing it is probably the same yes as the RV van roof question but just checking! Thank you!
Answer: yes.
Question: i have a room that is very hot in summer and cold in winter, must i applied in both sides of the wall and how many I need for 300 sq ft.?
Answer: Closer to the heat source the better. If you cannot apply under your roof shingles, then apply to the underside of the roof deck. If your radiant heat source indoors such as a fireplace or wood burning stove, you can apply to the walls and it will reflect the heat back in. If you don't have a radiant heat source indoors, then it won't do much in the winter.
Question: Should Radiosity 3000 be applied onto the actual roof shingles (exterior) or rather inside to the attic ceiling ?
Answer: If you have some good exterior paint, you can apply directly over the shingles. That is actually the best way to use it. Otherwise, it can be used inside the attic ceiling.
Question: I have a 30x30 metal work shop. How much temperature moderation can I expect if applied on inside surface of my workshop?
Answer: Radiosity reflects infrared heat, so if your goal is to retain heat inside your metal workshop then yes, you could coat the ceiling and the walls and any infrared heat sent in that direction would bounce back down. If you are trying to keep some of the heat of the sun from entering your workshop, you would paint the exterior of the structure.
Question: How does it help interior home with no wall insulation?
Answer: Yes, It will reflect 97% of the infrared heat from the sun. It is not dependent upon wall insulation. Also, if you have a wood stove, wood fireplace or radiant heated floor it will hold in the heat if painted on the inside walls.
Question: I want apply a reflective paint to exterior wall of family room. The wall is cement block...slump block. Will this product work? Do I need a primer first?
Answer: If your exterior wall is unsealed and unpainted (raw slump block) you would want to seal it, then prime it, then apply the Radiosity - this will give you the best result. If your exterior wall is already painted, and that paint is holding up well, then you could choose to skip the priming step and just do the Radiosity, that is your judgement call to make. Primer does what the name says, it primes a surface to accept paint, and in our experience paint jobs always turn out nicer with a stronger bond to the surface if you prime first.
Question: Can I walk on surfaces coated with Radiosity? Can I put this on my porch floor?
Answer: Absolutely not! This is made up of tiny glass beads, not made to be walked on. It's application is meant for a wall, or ceiling, or roof to reflect infrared radiation. If you want a cooler deck surface, paint with a lighter color (dark colors absorb heat, lighter colors reflect heat)
Question: What is the R value of one coat of your product?
Answer: There is no 'R' Value when dealing with radiant barriers.
Question: What is the smallest container you sell?
Answer: There is only one size: 1 gallon. Added to 5 gal of paint will cover about 1500 SF.
Question: I only need enough to do the roof of my vehicle, what is the smallest amount you will sell me?
Answer: The Radiosity 3000 is only available in the 1-Gallon size.
Question: Can I use Radiosity 3000 on my deck to keep it cool?
Answer: That is a really bad idea, this product is made of glass, and not designed to be walked on. it is meant for roofs, and attics, and walls and ceilings. NOT decks or porches.
Question: If I paint my entire ceiling and outer perimeter walls will this help keep the cool air in or the heat from coming in?
Answer: Radiosity 3000 is a radiant heat barrier which means it reflects radiant infrared heat from the sun. That means it keeps it out. It does not keep cool air in as it is not infrared.
Question: Can I use in paint on the outside of a old cast bathtub to help hold in the heat of the hot water?
Answer: This cannot be used for that application and we have nothing that is meant for that duty.
Question: I have brown metal garage doors that receive Texas West Sun and thus get very hot. Will this product work if paint is applied to either side of the garage door?
Answer: Yes, but it will work better if applied on the outside of the door.
Question: Can this be added to flat exterior paint? Will be applied to an east- and south-facing exterior (stucco.) Thanks!
Answer: Per the Radiosity instructions https://www.greenbuildingsupply.com/c..., it is supposed to be added to satin, semi gloss or gloss paint. It performs best in those sheens.
Question: What is the surface emissivity lowered to when using this product?
Answer: Radiosity is a fine powder that is mixed with a 5 gal bucket of paint. The emissivity will depend upon the quality of your paint. No testing has been done on this subject but I don't think it will change much. It is not designed to block vapor, only infrared radiation.
Question: Is this product applied to interior walls or behind stud wall? If it can go behind the wall, can I mix it with Caliwel Industrial Mold and Mildew Inhibitor?
Answer: Yes, Radiosity 3000 can go behind a wall or it can also be applied to the face of an interior wall. You can add this product to the Caliwel paint with no issue and then you have the benefits of both products! One pail of Radiocity should be used in one 5-gallon bucket of paint. This would be a unique and efficient application.
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