Hearth Pad Construction for New Englander 30NCH

[Nightowl & Woodpecker]

Hello Everyone hh: :red: ,

Absolutely feel blessed indeed to find this forum, thank you Hearth.com

We have been searching the web for hearth pad info as we are constructing our own. We didn't like the plain tile for our country cowboy home in Tehachapi, CA. We are confused.

We called Englander and they couldn't give specifics on how to construct one, but were helpful and kind even so. R values---huh?

We were going to construct the pad with two layers of 3/4 plywood for strength, then mortared to two 1/2" thick hardibacker board on top of each other, then 6x6 solid Slate tiles (with a diamond deco pattern set inside the edge) mortered on top of that.

Englander says we need a R value of 1.5 units or more. Checking hardibackers ratings on line I get a K value of 20.07 and an R value of 0.05. ????? We are still trying to find out the slate manufacturers R rating, but we are thinking that just eliminate the slate factor, and get the R values from underneath the slate, and we are homefree.

Englander said the pedestal Stove (we will install) can get up to 500 degrees under the pedestal with the stove burning at it's peak.

So, if anyone has any ideas or knowledge whatsoever, we would love to hear (read, hoot and peck, lol) about what to use. We also have heard contradictory information about the grout, Sanded verses Non-sanded. (Slate joints will be 3/16"). Also Latix modified thinset mortar, verses just thinset, and.........Siliconized grout verses regular grout????????????????????

We have read the previous posts about these subjects, but still would like to be updated or informed, we are avid woodstove users, but this is the first time we have actually installed one.

Thank you, thank you, thank you for your help in advance..........with best wishes
Ms Nightowl and Mr Woodpecker..............

 

[nshif]

What is below the 2 sheets of 3/4" plywood? subfloor? I doubt you need 2 sheets.
you would be better off using Duroc rather then Hardi as Duroc is speced for hearths by the manuf and is R rated at at .26 per 1/2 inch ( so is Hardi but not suggested for hearths by the manuf)
If you can stand some height gained dead air space with get you more R value at 1.43 per inch. this can be accomplished using metal studs in edge.

 

[Corie]

Micore 300 is also a valuable insulating material that is great for hearth construction. I'll try to get you more information on this later.

 

[nshif]

Corie
I looked for Micore when I was building my hearth and couldnt find it anywhere near here in Ca

 

[SlyFerret]

There is a chart on this page in the hearth wiki:
https://www.hearth.com/econtent/index.php/wiki/Hearth_Design/

It will give you R values of various materials.

-SF

 

[SlyFerret]

This is the thread on this site that I started for my Englander install.

https://www.hearth.com/talk/threads/11825/

-SF

 

[Hogwildz]

I obtained some micore , and all I had to do was drive to Philly 2x and help install a donor stove
Oh and do the roof & ladder work.
Thanks Corie.

 

[donatello]

Try the MICORE link for availability in your area. (broken link removed) (Put in your state and check the MICORE box.) I had a regional distribution center ship one 4'x8' to my local building supply (NOT a HOME DEPOT or LOWES) It cost me $38 total. (I thought that was reasonable)
I just built a hearth pad in November. I found I needed a larger hearth in front of my fireplace. I used (the great) HEARTH.COM for the components needed. I used two 1/2" sheets of DUROCK with one sheet of 1/2"MICORE in the middle and cheap (but look good) 1/2"marble tiles from HOME DEPOT. I bonded all together with thinset. I bought an appropriate cutting blade for my circular saw and cut it in my basement as apposed to outside, due to rain. (DON'T DO THIS ) After just visiting the MICORE site, I read this QUOTE," Sustained high level exposure to crystalline silica is thought to increase the risk of cancer." Cut the MICORE with a utility knife or hand saw only. Quote"Using power tools for cutting will generate high dust levels."-BIG TIME !
The remaining piece I used to block the chinmey, just over my PE insert.

 

[ATVriderINmass]

I just built my hearth for my Englander 30 NCH..I used 3/4 plywood,1 layer of micore,2 layers of durock and marble tile on top...they sell micore right up the street here from where i live...I actually have a piece 48" X 48" on my porch that will probably end up in the trash...to bad you weren't closer

 

[ATVriderINmass]

and micore is 1.1 R value

 

[SlyFerret]

Durock will cut great if you score it and break it like drywall. Get a good long straight edge and use a utility knife with disposable blades to score it. Score it good (maybe 5 or 6 passes) on the side WITHOUT the mesh backing. You should then be able to break it easily along the line you scored. I do not recommend using a saw to cut it. The saw will generate a great deal more mess than scoring and breaking. That, and you really don't want to breathe the dust.

-SF

 

[babalu87]

I obtained some micore , and all I had to do was drive to Philly 2x and help install a donor stove
Oh and do the roof & ladder work.
Thanks Corie.

Hey man, I was gonna ship it to yah........................... we just couldnt figure out how to get the Yuenglings back here