raised flue bricking

[John Burton]

on a raised flue evaporator do you fill between the baffles with sand to the tops of the rails?reviewing previous posts i dont seem to find much on this subject plenty of drop flue info... if anyone has a photo of a raised flue arch bricked without pans could you post it?thankyou

[WESTVIRGINIAMAPLER]

John,

From all the info I have ever seen, they don't recommend you using sand because it holds and traps moisture really bad. Seems most people use a lightweight fill called vermaculite or something similar. I have seen some raised flues that have the arch fully bricked and they seem to work good. :D

[brookledge]

John,
On mine I used vermiculite to fill up before cementing in the fire brick. You want to force the fire and heat up into the flues before it reaches the end and dives back down to go out the smoke stack. As Brandon said sand tends to hold moisture causing corrosion. Vermiculite or products simular are available at mason supply stores.

[mapleman3]

vermiculite with ceramicblanket right up to the top of the rails! then slope down to the back only about 6" from the stack and and leave about 2"open across down from the back rail so the fire only has that space to go throu.. that will keep the fire up in the flues good

[ebourassa]

I Just dried layed fire brick on the bottom, that is what I was told, i skim coated some mortar over the top of them and seem to work just fine.

Erik