By Milt from Los Angeles, CA on February 20, 2017
I want to find a product to stand between a furniture bureau and the fireplace to keep heat away from the bureau. Which product would you recommend?
By Owen on February 21, 2017
By Curt from Cornwallville, NY on November 27, 2012
Can you apply ceramic tiles directly to this board with thin set mortar? Also, I thought USG manufactured Micore 300? Is this a less reliable copy?
By Collin C. - NFI Master Hearth Professional on November 28, 2012
Answer:You can indeed apply ceramic tile directly to this product, but for better results it is recommended to use a layer of cement backer board over the Micore. This Micore 300 board is manufactured by USG. It is simply purchased from them and sold through the manufacturer SBI, hence the use of their name in the product description, even though they do not actually make it.
By Adam from TX on March 18, 2017
Has this ever been tested inside a safe (for fire protection)? Would this be better than drywall?
By Owen on March 20, 2017
has been tested by its manufacturer, US Gypsum, and is typically use in the building of hearth pads and clearance reduction applications as outlined the the NFPA (National Fire Protection Agency) 211 code. In lieu of sheet rock, you can also use cement/masonry board.
By paul from Ashland, OR on October 22, 2012
My wood stove manual has specified a floor pad with a R value of 1.2. What are my options of achieving this with a ceramic tile finish?
By Collin C. - NFI Master Hearth Professional on October 23, 2012
Answer:Most ceramic tile has a minimal R value, but can be used in conjunction with a product such as the Micore board you are viewing to achieve the R value you need. The R value of the board is 1.04 per sheet.
If you are able to obtain a ceramic tile that can be verified to have a value of .16 or higher, you will be in the clear to use only the 1/2 inch layer. Otherwise, a second 1/2 layer can be used to ensure proper insulation.
By Joseph Russo from Fairbanks, AK on January 25, 2012
So you sell 3/4 inch Micore 300. That's the thickest USG manufactures it and 3/4 inch would be ideal for my needs. Also my floor protection pad will require joints because of its size. What product do you recommend for joints when using Micore?
By Collin C. - NFI Master Hearth Professional on January 26, 2012
The thickest Micore product that we currently offer is this item. We do not offer a 3/4 Micore board at this time.
When installing Micore you can use a spreadable "mortar" that is used to seal the gap between cement board. This product is not a conventional mortar based material and is more along the lines of a silicone based product.
You may see this product at the following link:
By Charles from Santa Barbara, CA on May 13, 2015
How does one cut this SBI Micore-300 mineral fiber board?
By Brennan W. on May 13, 2015
Answer:Micore can be cut with a utility knife.
By Russ from Kalamazoo, MI on November 29, 2015
Can I mortar ceramic tile directly onto this SBI Micore-300 mineral fiber board or does it need a layer of cement board first?
By eFireplaceStore on November 30, 2015
Answer:A cement backer board should be used first. The Micore product is not a high density material and compressibility is high enough that concentrated pressure from a stove leg or other point of contact could cause a shift or crack in the tile veneer.
By Steve from CT on August 21, 2013
What is the value of one sheet of Micore?
By Collin C. - NFI Master Hearth Professional on August 21, 2013
Answer:The R-value of the Micore board is 1.03 for every 1/2 inch of board that is used.
By Ferman from NJ on August 25, 2016
Can this be used outside behind a outdoor barbecue grill as a fire protection for a wall?
By Will M. on August 26, 2016
Answer:This product cannot be used in an outdoor installation, but clearance reduction may be reducing to 12" via 24 gauge sheet metal spaced out 1" with a layer of cement board, followed by the stone or tile of your choosing. This is only permissible when allowed by local code enforcement as they will have the final say, so I will recommend a consultation with your local office prior to completing this application.
By Jason from Northport, AL on November 20, 2014
If I'm using double wall 2100 degree pipe that requires a 61/2" clearance and a stove that requires 7 1/2" clearance, will the Micore board allow me to sit the stove any closer to the wall and if so how close?
By eFireplaceStore on November 21, 2014
Answer:Clearance reductions for a wood stove can be made down to 12 inches by code. When clearances for the stove are already below 12 inches, further reductions cannot be made. That being said, using the Micore as a heat barrier is always a good idea for a close clearance installation such as yours.
By Michelle from St. Louis, MO on June 28, 2014
Is your mineral board similar or the same as vermiculite board? I am looking for something rigid and easily cut. I will be using it at a temp of approx 1600 degrees
By eFireplaceStore on June 30, 2014
The fibrous board is not the same as vermiculite. It is designed to be used as an insulating barrier behind noncombustible material or in place of combustible drywall behind a stove. It is not rated for the temperatures you expect for your application. The SBI Vermiculite Board - Pack of Two
can be cut to size and is rated for direct contact with flame. This product is commonly used to replace baffles in high efficiency wood burning appliances.
By Theresa from Boise, ID on July 9, 2014
Answer:They are similar in that they are both light weight, but I'm not familiar with the heat tolerance and R value of vermiculite board. When researching materials to use for our fireplace pad, the micore 300 seemed the best choice. With the other material we put with the micore we achieved the R value of 1.5 required for our stove. The Micore was more expensive but now that we have it built I'm glad we went with it. I feel confident that we wont have a fire.
By Cody from East Lansing, MI on July 9, 2014
Answer:It is nothing like vermiculite. It is lightweight and easily cut. As far as the temperature rating, that would have to be researched
By Joe from Newton, NJ on July 9, 2014
Answer:I chose Micore-300 (capped with a layer of Durock), because it allowed me to achieve the required R-value for my wood stove hearth, using the shortest height possible. There are other materials you can use, but I wanted to keep the overall height of the hearth (including tile) to under 1.5 inches.
Every other material I researched would have pushed my hearth thickness to well over 2 inches. If finished hearth height is not an issue, go with something else.
I know the Micore is pricey (and difficut to locate), but it is the best material currently available.
By Jacob from Virginia on July 10, 2014
Answer:I'm not familiar with vermiculite board, so I can't comment. But Micore is the same stuff that is in the pre-made hearth boards they sell at Lowes. It is rather soft, so it's easy to work with, though it tends to be a bit crumbly.
By John from Pennsylvania on July 10, 2014
Answer:I used this under a raised fireplace hearth and it worked perfectly. I needed it to meet the heat transfer requirements protecting the framing underneath. Under normal circumstances, it sees no more heat than what is radiated from the fireplace warming the stone on top of it. I have 2" blue stone on top of it which is heavy but spread evenly. It cuts very easily with a utility knife and will probably compress if a lot of weight is placed in small spot. In terms of durability I would compare it to a ceiling tile.
By Janie from Brenham, TX on December 15, 2015
We are building a home and plan on having a wood stove installed. The stove will have a corner placement and we have followed the manufacturers space recommendations. Our insurance company wants more for wall protection. We would like to create a heat shield wall using Micore covered with Metallaire (old tin ceiling squares). Is this SBI Micore-300 mineral fiber board ridged enough to stand vertically with the Metallaire? We plan to attach the panels to the wall with one inch ceramic insulators to create a free air space.
By eFireplaceStore on December 16, 2015
Answer:Micore has a density that is similar to drywall and should be able to serve as a backer for the metal tiles you mention, as long as they are not excessively heavy. If the tiles are 18 gauge or thinner, you will not have a problem.
By David from CO on February 6, 2016
What is the total sq footage of all four boards? It's not clear to me if the dimensions listed are for each or the four boards or the total.
By eFireplaceStore on February 8, 2016
Answer:This pack contains a total of 4 individual boards, with each board measuring 48 inches by 24 inches.
By Jessie from Fairhope, AL on January 29, 2016
Do I glue this SBI Micore-300 board to the subfloor or do I just screw it down?
By Brennan W. on January 29, 2016
Answer:This can simply be screwed down using wood screws.
By Brad from Ridgecrest, CA on December 29, 2014
I plan to use Micore 300 for a woodburning stove hearth. Can I put granite directly on top of the Micore?
By eFireplaceStore on December 30, 2014
Answer:Granite can "float" directly upon the Micore product. However, if you are planning to adhere the granite permanently, a layer of cement backer board should be screwed to the Micore first, as adhesive does not hold well to the mineral construction of the Micore product.
By Max from Hedgesville, WV on October 19, 2013
My insert manufacturer specifies a 1/2 inch Micore board and 24 gauge steel sheet for floor protection. They don't say which goes on top and which is the bottom next to the floor, or how to fasten it down. What is your recommendation?
By Collin C. - NFI Master Hearth Professional on October 21, 2013
Answer:The 1/2 Micore board should be used as the substrate with the steel sheet placed over the top of the Micore for additional protection and finishing. If the Micore is upon a combustible surface, wood screws should be used every 6 to 8 inches to secure the Micore to the floor. The 24 gauge steel can then be secured to the Micore using construction adhesive.
By Jonathan from Hartford, CT on September 26, 2013
I am debating whether or not I can, and should, tile directly over this product for use as a wood stove hearth. I read in your FAQ section that this can be done, however, I've also read in my research that it is not strong enough to hold a wood stove. Could you shed some light on your experience with this?
By Collin C. - NFI Master Hearth Professional on September 26, 2013
Answer:Both pieces of information are true. This item can be tiled directly over, but that is only recommended for a wall application. Furthermore, it is better to use a layer of cement backer board over the Micore before tiling. The backer board is a better material for the tile to adhere to.
The Micore is definitely not strong enough to be used on its own as a hearth. While it is a dense material, the weight of the stove legs will cause it to compress and indent. Manufactured hearth boards use Micore, but it is usually layered between sheets of steel or cement board. As such, you can use the layer of Micore as a base, then cover it with cement board, then apply your tile.
By Laura from AZ on October 15, 2015
What temperatures can this SBI Micore-300 mineral fiber board withstand? Is it easily cut? Also, is it similar to all vermiculite boards?
By Chris C. on October 15, 2015
Answer:This product can withstand sustained temperatures of 450 degrees Fahrenheit, but can withstand temperatures of 550 degree Fahrenheit intermittently. Micore will have the same consistency and feel as drywall, as such it can be easily cut with a utility knife.
By Heidi from Walla Walla, WA on October 13, 2013
In an earlier answer you indicated that one should screw the micore directly to the sub-floor. Then use thin set with a cement board over that. Then thin set with tile on the top. My question is regarding securing the cement board. Usually when installing the cement board to the sub-floor, I use thin set and then screw it down. But my guess is that the screws will have nothing really to grab when they get to the micore. So do I just use really big screws to get all the way to the sub-floor, or do I skip the screws for the cement board?
By Collin C. - NFI Master Hearth Professional on October 14, 2013
Answer:We usually recommend skipping the screws as a rule, but it really depends on the application. In many cases, a stove will require some sort of R-value for the floor protector. Using screws through the cement board will allow heat to be easily conducted down the screws to the sub floor, potentially causing scorching to the floor over time. If the stove is insulated well enough that it does not require the floor protector to have an R-value, this is not a problem. However, the thin layer of tile would not insulate well enough for a stove that does require a listed R-value and screws that penetrate to the floor should be avoided in that case.
By Sue from Mechanicsville, VA on December 17, 2015
I recently had a cast iron insert put into my fireplace and I thought we were in code, however we are not. I was told that I can buy micro-fiber boards to put on the cabinets closest to the insert to make sure there is no heat transfer, and this will make me in code so I can use my new unit! What other information can you give me about these boards?
By Chris C. on December 17, 2015
This product is most commonly used beneath a finish material such as tile or granite to provide a greater R value for a stove hearth pad installation. For more detailed information, I would refer to the submittal sheet
provided by USG.
By Audrey from GA on March 21, 2016
What does each sheet of SBI fiber board weigh 48 x 96 x 1/2"?
By eFireplaceStore on March 22, 2016
Answer:This product ships with four pieces measuring 48" by 24" by 1/2", with each piece weighing in at approximately 8 pounds.
By Gerry from San Jose, CA on January 26, 2013
Could I place a granite slab on top of the Micore 300 board?
By Collin C. - NFI Master Hearth Professional on January 28, 2013
Answer:The Micore 300 product is indeed dense enough for granite or stone to be placed on top of it. Most installations will require two layers of Micore to achieve the minimum required R value.
By Jared Trahan from Lafayette La. on January 17, 2012
At what temperature is this board capable of providing protection up to?
By Collin C. - NFI Master Hearth Professional on January 18, 2012
Answer:Per the manufacturer of the product, this board is able to provide protection from continuous temperatures of up to 450 degrees and intermittent temperatures of up to 550.
By Kimberly from Ohio on August 7, 2014
I have a couple of questions. If my husband builds a hearth platform out of wood topped with plywood, can I use a combination of micore board and durock on top of the plywood to get to the desired R-value of 2.0 before adding slate tile on top? Secondly, if we have fire-resistant drywall behind the wood stove, what is the best way to finish that out to make sure it has the appropriate heat protection (or should we have cement board instead of drywall on the studs)? I've seen a lot of reference to ceramic spacers and 24 gauge sheet metal, but (not to sound stupid) do you fasten the spacers straight to the drywall or does something need to go on top of the drywall? I realize maybe I shouldn't be asking part of this questions here, but I have been looking online for hours and can't find answers.
By eFireplaceStore on August 8, 2014
Answer:The short answer to your initial question is yes. As long as enough Micore and cement board is used to achieve the required R value (2.0 in your case), the platform beneath can be fully combustible. The slate tile can be applied directly to the cement backer board. The tile itself will have its own R value, but I don't recommend factoring that in, as the porosity and density of the slate will vary.
As for the second question, the appropriate material to use will actually depend on how close the stove will be to the wall. If the stove is positioned so that it meets minimum required clearances to the wall, standard drywall could be used. Cement board, sheet metal, or any other wall protection would only be needed if clearances need to be reduced even further. If you would like to provide the model of stove you have, whether you are using single or double wall stovepipe, and the intended proximity to the wall, I will be happy to advise further.