32 Inch Cape Build

[MarkJerling]

. Thanks for the nice words, Barry Baza. We've had such great weather these past couple of weeks I'm still plugging along. We did have a (rare) small earthquake here last week which made me think
about the stone pedestal my oven sits on. This was a left over from a cob oven I had a few years ago and I reused it. I sometimes regret not building a typical cinder block base that most people use. At any rate, that earthquake got me thinking, if that pedestal were to weaken and break up, my oven would be lost. So I spent the last few days installing 2 concrete columns on the two front corners of the hearth. Poured them yesterday with a steel tube bridging the columns. Hopefully that will add a some support and a little peace of mind. The rear of the hearth is supported by earth (dirt and rocks).

Well done. I did mine with base isolation, this being a shakey island and all! LOL

[CapePizza]

Where my flue pipe exits through a slab of granite there is a 3/8 inch space. I'm looking for what the best way to fill this space would be... .I'm thinking either hi temp caulk or home-brew mortar mix.
Any suggestions? Would either one work..... would either one be better over the other... .or is there another option I should consider? Thank you for the help.

[MarkJerling]

Where my flue pipe exits through a slab of granite there is a 3/8 inch space. I'm looking for what the best way to fill this space would be... .I'm thinking either hi temp caulk or home-brew mortar mix.
Any suggestions? Would either one work..... would either one be better over the other... .or is there another option I should consider? Thank you for the help.

I would use some fibreglass fireplace door rope in the gap. If you need it to be waterproof too, you could go over the top of that with some high temperature silicone.

[Chach]

Where my flue pipe exits through a slab of granite there is a 3/8 inch space. I'm looking for what the best way to fill this space would be... .I'm thinking either hi temp caulk or home-brew mortar mix.
Any suggestions? Would either one work..... would either one be better over the other... .or is there another option I should consider? Thank you for the help.

I would go with high temperature caulk. You don't need to get fancy here. there also is a storm collar you can put on as well

[CapePizza]

Thank you both for the suggestions. I suppose I could force some fibre rope in the space, but in looking at it again... it's pretty tight, so I'm not sure there's enough room there without taking a chance and denting the flue pipe by jamming in the rope. The idea of a storm collar seems good (with the high temp caulk) , I like that. Thank you again.

[CapePizza]

Question about finishing the dome's surface. I'm hoping to start covering the oven with the insulation blanket, wire lath, and perlcrete covering.... and I'm planning how to finish the surface of my oven. I'm NOT planning on building a structure around my oven and plan on just some sort of stucco finish over the dome's perlcrete coating. We live in a year round moist environment with winters that can at times produce freezing rain and snow. So need the finish layer to be strong and as waterproof as possible. I was watching some Forno Bravo YouTube videos on how they finish their ovens and thought the process might be good for my oven, so just would like to hear other's thoughts about the pro's and con's of how this might work for my oven.

On top of the perlcrete layer I'd trowel on a layer of "base coat commercial grade quickcrete stucco" described as a standard mason mix stucco. On top of that trowel on a layer of Marble Coat. On top of that brush on a layer of SealKrete Water Proofer (which supposedly seals the marble base coat). On top of that paint a layer of McCloskey color glaze.

I'd like to hear any thoughts on how this might work for my oven. Thank you very much for any feedback.

[CapePizza]

Thought I'd ask again since no replies from yesterday's inquiry (see last post #216).... but I'll ask another way. Living in a moist environment, after the perlcrete layer on the dome over the insulation blanket, is there a recommended final stucco finish procedure anyone can recommend? One that would provide waterproofing. Any specific types of stucco you can recommend? Thank you.

[CapePizza]

After a bit more research, has anyone use this product (Sika #107 Top Seal)? See attached. So, I'm thinking of troweling a base layer of typical mortar mix over the perlcrete. Over that mortar mix trowel this Top Seal #107 product over that, which would provide the waterproofing I'm looking for. Does this seem like a good way or finishing the dome? Thanks.

[UtahBeehiver]

I think, Les (Les' Build) from Lake Tahoe used and elastomer stucco coating the seems to hold up well in his high elevation and cold climate. You will have to look in his build thread for the name, Dura something.

[CapePizza]

Thanks, Russel. I looked at Les's oven build thread. Dryvit is the "system" sealer he used. I looks like it's something similar to Top Seal #107 I'm looking at. I suppose there's a few of these waterproof sealer systems available.... finding the best one for our environment and someone locally who carries it is the next step. Thanks for the reply.

[UtahBeehiver]

Yes, Dryvit is the name, kind of close with my recall. I think several members have used this product.

[MarkJerling]

After a bit more research, has anyone use this product (Sika #107 Top Seal)? See attached. So, I'm thinking of troweling a base layer of typical mortar mix over the perlcrete. Over that mortar mix trowel this Top Seal #107 product over that, which would provide the waterproofing I'm looking for. Does this seem like a good way or finishing the dome? Thanks.

I have used a number of Sika products over the years. All are good. I think that should work as a waterproof plaster. I intend adding a layer of the same product to my plaster render oven as the existing outer layer is not waterproof enough for my liking. But then, I probably don't have to as I have a waterproof foil layer under. Most people here advise against a foil layer for fear of trapping moisture under.

[CapePizza]

After yet more research and a conversation with a rep at Silpro, I'm going to use this method noted below for the final render over the perlcrete .......for those that are interested.
This should provide the 1) strength and 2) the weatherproofing I'm looking for.

1) Over the perlcrete surface of the dome brush straight (not diluted) C-1 All Acrylic mixture. It's kind of sealer and bonding agent.
2) When that dries, trowel on a layer of FSB Fiberglass Surface Bonding Cement (mix with 50# bag is 1/2 water and 1/2 C-1= to 5 or 6 quarts of this mixture)
3) Next day or when the FSB cures, trowel on a layer of Concrete Finish (this comes in white or gray. I'll get white and can be tinted). Mixed with the 1/2 water -1/2 C-1 mixture.
4) When cured, coated with Silocks Plus WB ( a clear sealant).

[CapePizza]

Finally got nice weather to install the insulation blanket. 3 layers. Also installed wire lath to hold it all in place. Still need to tuck some pesky corners and edges down. I'd like to start the curing fires now. Still hesitant though with winter approaching doing the curing fires now might be a waste of time since I'll have to do them again in the spring. But the alternative is to do them now and if I get some more nice weather, I'll then do the P-Crete layer and then another round of curing fires. I plan on building one of those rotating radius templates hanging from the rafters to get the oven to be as round as possible when doing the P-Crete.

[Ope-dog]

You build continues to look outstanding!!! Great work. I just put up a temporary structure around my build this weekend, so hopefully I will provide enough cover and warmth to allow me to build through the winter.

The stone around the base of your chimney looks great! Your entire entry looks great, for that matter!