Supporting a wood-fired arch--ideas?

[Brookhaven Maple]

I know the prevailing wisdom/practice is to pour a concrete base to support one's evaporator. Not being able to do this, any suggestions/alternatives for supporting an arch/evaporator on a wood floor? The floor is plywood and well supported with 6x6's.

Read something last year about someone doing this but can't find the discussion thread.

[Thompson's Tree Farm]

I have no experience with this so am just throwing out ideas. Could you lay a piece of sheet steel over the wooden floor where the fire box and the fire pit would be? Then line the bottom of the fire box with 1" thick fire brick? Most of the heat is going up so I'd guess the key would be keeping hot coals etc from ever getting close to the wood surface...

[ericjeeper]

1/2 inch thick fibermesh reinforced concrete board, They come in 24x48 inch sheets. Easy to handle, not to difficult to cut.
Or 12x12 concrete walk pavers.

[KenWP]

In the house to put a heater in the kitchen years back before I bought the house they poured a 2 inch pad on top of the floor to place the heater on. Its common practice around here to do it that way I am told. Would be pretty simple to do it in a suger cabin.

[Clan Delaney]

I like the concrete pavers idea, but I'd still go with the concrete board as well. Embers could fall down between the pavers. Put the board down as a barrier (or sheet metal of some sort), and then use pavers or blocks as extra insulation.

[maple flats]

My old 2x6 was on a wood floor and it met fire dept inspection. I had the firebox end of the arch up on 12" concrete blocks with a 18 gauge galvinized cap under the arch and extending 30" in front and 12" to each side (only in front not along the sides) This worked for 2 seasons until I poured cement and changed to my current 3x8. However I did not dare use a draft blower because of blowing embers potential. I am now all concrete. The wood worked but I did need to re support under the floor each day as the frost came out of the ground and that was a pain. However my joists were only 2x8 rough cut hemlock on 16" centers with a main beam of 3- 2x8's nailed together directly under the evaporator. The joists were 16' and the span on the main beam was only 8' between posts but the posts rested on rather soft ground under the main beam. The second year I had it I poured my concrete footer for the evaporator sized for room to grow to a 3x0. That year I did not need to re level during the season. After that season the floor got removed, blocks were laid up and everything was filled with crushed stone and the evaporator slab was poured resting on the blocks. My concrete floor is now complete and the floor is not tied to the evaporator slab but can freely float up and down if needed. Hopefully I compacted the stone properly and the floor will last a long time. If I ever do it again I will pour the concrete before building everything in the way. In fact I hope to add a 14 x 20 addition this year with a heated section for a bathroom and adjacent will be heated for an RO. The rest will be kitchen which will be heated with a wood stove. The cement will be poured first before the walls etc.

[Brookhaven Maple]

Thanks guys!

Some very helpful ideas for now and several for the future.

[Justin Turco]

Maple Flats mentioned getting the firebox up in the air by putting it on cement blocks. I just want to point that out as being a good idea. It makes it a lot easier on your back when adding wood. also, Extend the concrete board, (if you go that route) out in front of the firebox a bit. I'm always losing coals out the front when adding wood. Have a good season.

Justin