36" Build Alberta, Canada

[Vee]

Hello,

I am planning my vent arch and vent opening and was wondering if anyone had any insight into the following:

Sounds like a 36" dome a 6" Duravent is recommended. Would 8" be better or too big? I see I can order 7" diameter. Would it be best to go with the 7" as an in-between size? Has anyone used a 7" on a 36" dome?

Are there any guidelines for how large my vent opening should be for each size?

Thanks!

John

[NCMan]

I think either a 6" or 7" works just fine for a 36", but I also think that the smoke chamber/throat plays a big part in how an oven draws. Not long ago, I saw a 42" oven w/a 6" chimney and it worked perfectly. However, the builder incorporated quite a smoke chamber for it and it performed great. I wouldn't recommend doing it for the average builder, though. My point being, there's more to how an oven draws than just the flue size, although it's obviously very important. Also, to be technical, it's really not the size of an oven that dictates a flue size, but more of how big of an opening there is. It's really as simple as air in, air out. If, for some reason, someone makes a big, wide opening, I would lean towards a slightly bigger flue. My 2¢.

[Vee]

Can anyone tell me do you install the 1 inch of thermal mass coating before or after your cure? I assume before?

Thanks!

[david s]

If adding extra thermal mass, give it at least a week to cure a further week to dry before proceeding to insulate. If doing a vermicrete layer over the blanket also give it a week to dry, then begin your drying fires.

[Vee]

David,

Thanks so much for the quick response. I just placed the final plug in yesterday and was thinking to add some refractory mortar on top of the bricks for some added thermal mass. No vermiculite layer of the blanket since I'll be enclosing the dome. I'm planing 1" refractory mortar and then 3" of the blanket and filling the rest of the enclosure with loose vermiculite. Just so I'm clear do I wait a week before I can add the 1" of mortar or do I add it now and wait a week?

Sorry if I'm not understanding I just want to get it right!

Thanks

John