High temperature caulking between hearth tiles

[helm78]

I’ve just installed a new wood stove and
I was wondering if it’s safe to use high temperature silicone caulking (home builder rtv max temp 232 degrees Celsius) between the gaps in the tile of my hearth pad?

I built a hearth pad with a bottom layer of 1/2 rigid insulation, then 3/4 plywood, two overlapping layers of scrap metal and then porcelain tiles. Just the materials I had laying around.

 

[begreen]

It may be possible, though a bit messy. Regular tile grout would be better and easier.

What stove is this for?

Note that the insulation under the plywood does nothing for the hearth. Normally cement board is placed on top of the plywood to provide a good bonding substrate for the tile. How are the tiles in this hearth bonded to the metal?

 

[helm78]

It may be possible, though a bit messy. Regular tile grout would be better and easier.

What stove is this for?

Note that the insulation under the plywood does nothing for the hearth. Normally cement board is placed on top of the plywood to provide a good bonding substrate for the tile. How are the tiles in this hearth bonded to the metal?regency r3

It may be possible, though a bit messy. Regular tile grout would be better and easier.

What stove is this for?

Note that the insulation under the plywood does nothing for the hearth. Normally cement board is placed on top of the plywood to provide a good bonding substrate for the tile. How are the tiles in this hearth bonded to the metal?

It’s a Regency R3. The plywood was originally for some hardibacker and thinset plan but 1 out of 3 buckets didn’t cure for some reason. Even though they were all applied the same way. The tiles are just glued down with some adhesive. My wett inspection only required spark protection from the hearth pad not worried about radiant heat.

 

[begreen]

The tiles are just glued down with some adhesive.

The adhesive is the weakest link as it's likely to be combustible. This is not the best way to build a wood stove hearth.

Grout is the best way to fill tile gaps.

 

[helm78]

Thanks