Hearth thickness

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MontanaLife

New Member
Mar 24, 2023
26
NW Montana
Hi everyone.
I'm installing a Vermont Castings Vigilante wood stove.
For a hearth pad I have OSB (1/2"), durock sheets (1/2"), and ceramic slate look tile tile 3/8".
Questions:
1. Does the pipe need to be 18" from the wall all the way to my 22 foot ceilings? It'd double wall pipe.
2. For the hearth pad how thick does it need to be? Can the hearth board and durock be installed directly to the floor, or do I need to build a 2x4 frame and build the pad on top of that?
 
The specs for everything should be in the manuals.
I wouldn’t think you need a frame for the hearth necessarily unless you’re doing so to add height.
 
If you know about when it was made, there may be a manual online
 
do you have a rough time frame of how old the stove is?
 
Single wall pipe requires 18 inches to any combustible material. 22 feet high requires double wall to prevent excessive cooling through pipe walls as exhaust gases rise. Double wall connector pipe has a reduced clearance of 6 inches to combustible materials.

The stove installation manual will give the R-value of floor protection required as well as the size. Make sure you use the correct manual.

Raising it is up to you, if you want the stove on a hearth of some sort, or on protected floor. The older you get the higher you tend to like it.

Thermal protection can get confusing because all materials do not give their r-value. Some will give k-factor which is thermal conductivity by the inch of thickness and others may give C, or thermal conductance. When R or thermal resistance is not given, a formula is needed to convert C or k to R.

See if you have the R values of the materials you have first. Then add the rock board, setting cement and tile or brick together to find total R to be sure it has the minimum resistance required.
 
The manual for the old VC stoves is posted here in 3 parts:
It's strongly recommended to use double-wall stove pipe for runs greater than 8 ft.
The hearth construction requirements will depend on whether the stove has the VC bottom heat shield or not. If it does then the method proposed is fine. If it doesn't then there should be more heat protection in the hearth layers. Doubling up on the cement board to make a 1" thick layer under the tile should suffice if Durock Nex-Gen is being used.
 
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The manual for the old VC stoves is posted here in 3 parts:
It's strongly recommended to use double-wall stove pipe for runs greater than 8 ft.
The hearth construction requirements will depend on whether the stove has the VC bottom heat shield or not. If it does then the method proposed is fine. If it doesn't then there should be more heat protection in the hearth layers. Doubling up on the cement board to make a 1" thick layer under the tile should suffice if Durock Nex-Gen is being used.
Thank you. Yes, montana law requires double wall for longer distances (ours is 22 feet). The stove does not have a bottom shield.