Hushboard as hearth pad material?

par38lamp said:

While researching sound attenuating materials form my very noisy bedroom (backs up to a road where all the dump truck/hauling companies decided to use as a short cut trucking route~100% residential road), I found Hushboard from Georgia Pacific. It claims to have a R value of 1.43 per 1/2" inch per the brochure.

I suspect it's combustible, since i'ts made of wood, and it's non-structural, so other means would be needed for protection and support, but just thought I'd throw that out.

http://www.gp.com/build/product.aspx?pname=Hushboard®+Sound+Deadening+Board&pid=1071&hierarchy=pc

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par38lamp,

Your link appears to be broken...I couldn't get it to work. I did find this link:

http://www.gp.com/build/product.aspx?pname=Hushboard®+Sound+Deadening+Board&pid=1071&hierarchy=pc

Anyway, I'd suspect it's not for use in hearth pads. Better to use Micore 160 (R value of 2.86 per inch) or Micore 300 (I think R value of about 2.34 per inch), both of which are better for these purposes.

What about ceiling tiles? They are flame retardant. Maybe for a between layer sandwich? Anyone know the R-value?

Hogwildz said:

What about ceiling tiles? They are flame retardant. Maybe for a between layer sandwich? Anyone know the R-value?

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HW, during my research into micore, some ceiling tiles are made of micore. But as stated above 300 is the stuff to get. The ceiling tiles are not nearly dense enough to use imo, even as an intermediate layer. So... yes you can find ceiling tiles made of micore, but it's really soft and squishy. My only thoughts were that such ceiling tiles could be used as a backing or intermediate layer for wall protection, but applied in a pad, I think you'd end up cracking your overlayment, whether it be stone, tile, etc. My 2 cents.

-Kevin

wrenchmonster said:

Hogwildz said:

What about ceiling tiles? They are flame retardant. Maybe for a between layer sandwich? Anyone know the R-value?

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HW, during my research into micore, some ceiling tiles are made of micore. But as stated above 300 is the stuff to get. The ceiling tiles are not nearly dense enough to use imo, even as an intermediate layer. So... yes you can find ceiling tiles made of micore, but it's really soft and squishy. My only thoughts were that such ceiling tiles could be used as a backing or intermediate layer for wall protection, but applied in a pad, I think you'd end up cracking your overlayment, whether it be stone, tile, etc. My 2 cents.

-Kevin

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Wrench,

I called USG who makes Micore and they sent me free 12" x 6" samples (will actually send you whatever you want in 12 x 6 samples) and both the Micore 160 and 300 are fairly sturdy.

castiron said:

wrenchmonster said:

Hogwildz said:

What about ceiling tiles? They are flame retardant. Maybe for a between layer sandwich? Anyone know the R-value?

Click to expand...

HW, during my research into micore, some ceiling tiles are made of micore. But as stated above 300 is the stuff to get. The ceiling tiles are not nearly dense enough to use imo, even as an intermediate layer. So... yes you can find ceiling tiles made of micore, but it's really soft and squishy. My only thoughts were that such ceiling tiles could be used as a backing or intermediate layer for wall protection, but applied in a pad, I think you'd end up cracking your overlayment, whether it be stone, tile, etc. My 2 cents.

-Kevin

Click to expand...

Wrench,

I called USG who makes Micore and they sent me free 12" x 6" samples (will actually send you whatever you want in 12 x 6 samples) and both the Micore 160 and 300 are fairly sturdy.

Click to expand...

Cool, enough "free" samples and I might be able to do the hearth LOL. I have decided to tear up what I just did. 1/2" of permabase & 1/2" of dura rock with 1/2" slate 16"x16" on top is just not enough. The insert put alot of heat out the front, with a stove themo on the slate its reaching 100+° even over 150. I don't want to come home some day & find a charred house shell left. I had only a hearth rug over the carpet before & it was not bad. But the slate soaks alot of heat up. Technically PE calls for 16" from fireplace opening. Which I have 12" the first 6" of the lower slate extension doesn't get hot, but about 8-10" out the slate takes alot of heat on. This is really about 18+" away from the fireplace opening, but I want to sleep well at night.
Working on getting some micore from another member. No dealers in my area.

castiron said:

Wrench,

I called USG who makes Micore and they sent me free 12" x 6" samples (will actually send you whatever you want in 12 x 6 samples) and both the Micore 160 and 300 are fairly sturdy.

Click to expand...

Isn't the difference between 160 and 300 the thickness? I think the densities are the same. The ceiling tiles I inspected were very flimsy, with multiple holes (like worm holes) in the micore. You could easily flatten the ceiling tiles between your thumb and index finger. Good tip on the samples... however collecting enough to construct a hearth may prove difficult.

-Kevin

MICORE® Brand
300 Board

Description MICORE® Brand 300 Board from USG is a superior substrate for fabric and vinyl-covered wall panels, office
dividers and tackboards. An excellent core for chalkboards, stove boards, and similar applications, MICORE Brand
300 Board offers outstanding resilience, superior machinability, high “k” factor, heavy density and highest
surface hardness of any MICORE board.

Advantages MICORE Brand 300 Board is nearly 50% lighter than particle board, which allows for easier handling and lower
freight rates. It also outperforms gypsum panels in workability—the inorganic mineral fibers resist moisture,
minimizing expansion and warpage. And the board cuts quickly to size and shape specifications using standard
equipment while adapting readily to last-minute design changes. What’s more, MICORE Brand 300 Board outperforms
particle board and other wood-fiber boards for flame spread and sound absorption.

Sizes Thickness 3/8" (.375)
7/16" (.438)
1/2" (.500)
5/8" (.625)
3/4" (.750)
Tolerances Thickness +-.015"sanded and coated
Width and Length (per lin. ft.) +-1/64" ( +-.016")
Physical Surface Burning Characteristics Flame spread1 25
Properties Smoke developed1 10
Density (pcf) 24+-2lbs./cubic ft.
Weight 500-2000 lbs./MSF
Modulus of Rupture 350-450 lbs./sq. inch
Modulus of Elasticity 30,000-35,000 lbs./sq. inch
Tensile Strength Parallel to surface 225-275 lbs./sq. inch
Perpendicular to surface 20-30 lbs./sq. inch
Hardness (Janka Ball) 50-70 lbs.
Hygrometric Expansion From 50% to 90% R.H. 0.1%
Thermal Conductivity k Factor .458
R Value (1/2" board) 1.09
1. Underwriters Laboratories, Inc. Classified as to surface burning characteristics (File No. R-11588). Underwriters Laboratories, Inc.



Physical Surface Burning Characteristics Flame spread1 25
Properties Smoke developed1 10
Density (pcf) 24+- 2lbs./cubic ft.
Weight 500-2000 lbs./MSF
Modulus of Rupture 350-450 lbs./sq. inch
Modulus of Elasticity 30,000-35,000 lbs./sq. inch
Tensile Strength Parallel to surface 225-275 lbs./sq. inch
Perpendicular to surface 20-30 lbs./sq. inch
Hardness (Janka Ball) 50-70 lbs.
Hygrometric Expansion From 50% to 90% R.H. 0.1%
Thermal Conductivity k Factor .458
R Value (1/2" board) 1.09
1. Underwriters Laboratories, Inc. Classified as to surface burning characteristics (File No. R-11588). Underwriters Laboratories, Inc.
(File No. MH-14487), (DFCV2) recognized component for category of miscellaneous heating and cooling appliance accessories.





MICORE® Brand
160 Board

Description Used as a substrate or core, MICORE® Brand 160 Board from USG improves the quality and performance of your
design in various applications, such as open-plan partitions, office screens, dividers and tackboards. The
board combines lightweight properties with the strength and stability of heavier boards.

Advantages MICORE Brand 160 Board is nearly 50% lighter than particle board, which allows for easier handling and lower
freight rates. It also outperforms gypsum panels in workability—the inorganic mineral fibers resist moisture,
minimizing expansion and warpage. And the board cuts quickly and easily to size and shape specifications
using standard equipment while adapting readily to last-minute design changes. What’s more, MICORE Brand 160
Board outperforms particle board and other wood fiber boards for flame spread and sound absorption.

Sizes Thickness 3/8" (.375)
1/2" (.500)
5/8" (.625)
3/4"(.750)
Tolerances Thickness +-0.015" sanded and coated
Width and length (per lin. ft.) +-1/64" (+-.016")
Physical Surface Burning Characteristics Flame spread1 25
Properties Smoke developed1 10
Density (pcf) 16"2 lbs./cubic foot
Weight 500-1550 lbs./MSF
Modulus of Rupture 200-300 lbs./sq. inch
Modulus of Elasticity 30,000-35,000 lbs./sq. inch
Tensile Strength Parallel to surface 90-120 lbs./sq. inch
Perpendicular to surface 10-15 lbs./sq. inch
Hardness (Janka Ball) 40-60 lbs.
Hygrometric Expansion From 50% to 90% R.H. .25%
Thermal Conductivity2 k Factor .35
R Value (1/2 " board) 1.43

1. Underwriters Laboratories, Inc. Classified as to surface burning characteristics (File No. R-11588).

Spec sheet foe MICORE® Brand 160 Board and 300 Board

http://www.acoustics.com/specs/USG_product/usg_spec.pdf#search='micore

Dumb question on hearth design - having built a "sandwich" to cover with tile, how much thickness does one allow for the thinset cement that you glue the tiles down with? Is there much "fudge room" in that number? I am thinking in terms of if one is trying to build something that is flush with an existing floor, it seems important to me that you match the levels as closely as possible, and I was wondering what the best way is to make up any thin shortages?

Gooserider