Casa2G90 Installation, Vancouver Island

[Mattias]

I have found other build threads with photos extremely helpful as I began to plan for the Casa2G90 installation. We have had it since last May, so it's been sitting around for 8 months while we built our outdoor kitchen area in the mean time. Compared with that project, this Casa install has been lightning fast and super easy! We're thankful that we ordered a modular kit for this reason.

We had the crate shipped to Washington State and picked it up while we were down on a prearranged visit. We brought it back in a utility trailer and had to pay GST on it at the border. They opened the crate lid to have a look inside.

keywords: Casa2G90 installation photos build enclosure Canada

[Mattias]

We are building a steel stud enclosure for hardiepanel, and we wanted the hearth flush with the base. I built an edge form with a strip of 1/2"x3/4" wood that supported the edge form on the top surface of the blocks. This resulted in an interesting groove on the outside face of the hearth, but we plan to cover it with hardiepanel or hardietrim. The hearth surface is level, which is great. We had perfect temperatures for working with concrete.

We used a reciprocating saw with the blade removed-- it worked really well against the edge form to vibrate most of the bubbles out.

[Mattias]

We double and triple checked our measurements to make sure the dome-to-steel-stud measurement left enough room for the 3" of ceramic insulation blanket, and, of course, that the oven front was square and parallel to our hearth.

Since our hearth was level, we used a few bricks around the perimeter as guide for the 1/2" of bedding sand on top of the insulation board. We screeded the sand with a level, which made it pretty quick and easy. With the dome in place, we adjusted the seam gaps to 1/4" and then mortared the seams as per the FB instructions.

Our hearth is 56"x56" because we wanted an enclosure with low visual weight-- i.e. we wanted the structure as small as possible. Considering the oven location on our property, we didn't want it to be a large, chunky feature. This hasn't left us with a whole lot of wiggle room, but I don't foresee any hiccups since I modelled extensively with Google Sketchup.

The bricks in the oven landing area will support the decorative arch, and will sit proud of the oven enclosure's siding. I figured this would be a good place for the hardiepanel siding to butt against the oven.

We left a small gap between these bricks and the oven floor tiles as a thermal break-- I'm not sure if this is required, but we thought it wouldn't hurt.

The bricks themselves are reclaimed insulation bricks from a chimney we tore down four years ago. We're still getting used to mortar, and our loose mix resulted in a lot of smeared mortar on the brick faces. We'll need to clean that up later. I've now learned to make a really dry mortar mix, which helps this issue.

[Mattias]

The decorative rough brick arch, while entirely functional, isn't exactly symmetrical, but it's pretty close. Once we clean up the mortar from the brick faces, I think it'll be alright. Our outdoor kitchen has a lot of less than perfect finish details, so we're fine with a more rustic than perfect finish level here on the oven. I think we'll seal the bricks and mortar once we get them cleaned up, and we'll stuff some fibreglass rope into the thermal break (not pictured). While we wait for the arch to cure, I will begin installing the steel stud tracks and cutting wall studs. We plan to start the curing fires on the weekend, since we mortared the oven dome last weekend.

Our plan is to run the chimney pipe right through the peak of a 5-12 gabled roof. We have a few local metal shops around here, and I'm hoping one of them could fabricate a roof peak flashing that acts as a chimney collar. I read someone's post that included a drawing of such a piece, but I can't find it now. I'll post about that later once we get to it, but I'm curious if anyone out there has an easy solution to the 6" chimney-through-gable-roof-peak problem. We get a lot of rain and wind here, and I want to make sure it's tight and secure! Please chime in if you have a suggestion. Thanks!

[RandyJ]

Nice looking build. What gage steel studs are you planning to use. I did mine with 18 gage. They were nice and heavy-duty. I do not feel that there is any chance it will be damaged by wind or snow load. I don't know that I would say that about 20 gage and don't even consider 25 gage they are like paper.

Keep up the good work it is looking great. Any little imperfections are not defects they are charm and character, and what gives the oven it's identity.

Randy

[Mattias]

I did mine with 18 gage. They were nice and heavy-duty. I do not feel that there is any chance it will be damaged by wind or snow load.

We're using 20 gauge 2x4 equivalent, with 14" studs on centre. I'm not concerned about the strength of the enclosure-- the wind and rain (and occasional dump of wet snow) around the chimney through the roof peak is what I think needs to be beefy. The attached photo is the type of flashing that I think will perform well-- but I would love input from others who have gone through the roof peak with an insulated steel chimney. What I like about the design below is that there is a conical shape which would act a little bit like a storm collar, or at least give the pipe some horizontal stability in a real blow. We'll get gusts around 70 - 80Km where the oven sits.

I have searched photos on the forum to find a close-up of of this type of chimney flashing, but can't seem to find any installed photos. Perhaps I should post this question in another forum section?

[RandyJ]

I would think that should work just fine for the roof peak. I did not do mine that way so I don't have a lot of experience with that style. If you want I think there is a chimney section in the forum. Might be a good place to ask if you do not get the help you are looking for. What are you going to do for the outside finish on the enclosure? Keep up the good work and good luck.

Randy

[Gulf]

Mattias,

If you have a double walled flue, you should be able to stabilize it at the peak, just prior to exiting the roof. Though it can handle some, the "boot" should not have to carry the all of the wind load. It should be just considered as flashing. If the flue converts to single wall, that conversion should be well above the peak, and should have a separate flashing collar. I read where you are using metal studs. What are you using for rafters, decking and roofing material?

[Mattias]

Thanks Gulf. It's the stock single-wall 6" duratech flue that came with the kit. I talked to a sheet metal guy today who can make this flashing, but he also stated that it wouldn't function as much of a storm collar. You mentioned a conversion from double-wall to single wall occurring above the peak-- is this for concerns with heat conducting into the roof? As for chimney support before it exits through the flashing-- would you recommend some metal strapping?

We're using 2x4 metal studs to make rafters on a 5-12 pitch gable roof. We are planning to screw galvanized metal roofing sheeting directly onto the 2x4 bracing between the rafters, which will be 14" on center. For two of the rafters, we'll need to move up the bottom chord as a collar tie to allow insulation clearance at the top of the dome. The whole enclosure is pretty small; he side wall height and soffits will be only 18" above the hearth surface.

As for siding, I picked up 7 sheets of new CedarMill HardiePanel at an auction, so the plan is to get some hardietrim and go for a board and batten painted finish.

[Gulf]

Yes, it is to prevent heat from conducting from the single wall pipe to supports, straps or flashing. Even double wall requires a minimum "stand off" distance from wood lathing. That distance varies among local building codes. It will need to be double walled at the point where it exits the peak. And, at any point where you strap, brace, support or flash the flue. Forno Bravo sells the double wall pipe as an upgrade to the kits for double wall applications. An enclosure is one of those cases where double wall pipe is needed in my opinion. It is probably too late now, since you have already recieved your kit. I'm not sure about Canada, but 6" is a standard stove pipe size here in the states. You may be able to source some double wall stainless steel pipe locally. I would get an off the shelf storm collar before I had the special boot made. Give the secton of double wall and the storm collar to your fabricator. He will then know what he has to fit. Also, I would be thinking about a spark arrestor flue cap. That may not be an issue for ya'll. We have burn bans around here from time to time. If you need a litte more height for your flue or gable construction, you may still be able to use the single wall (or part of it) as a bottom section. You can wrap it in cf insulation or bury it in vermiculite. It would be easier and cheaper to do that way than to convert back to single wall above the ridge line.

[david s]

We left a small gap between these bricks and the oven floor tiles as a thermal break--

The bricks themselves are reclaimed insulation bricks from a chimney we tore down four years ago. We're still getting used to mortar, and our loose mix resulted in a lot of smeared mortar on the brick faces. We'll need to clean that up later. I've now learned to make a really dry mortar mix, which helps this issue.

There are two problems using insulating bricks for the front decorative arch. Firstly they are not very strong making breakage and abrasion likely in a position where they'll get a fair pounding from metal peels,heavy pots and wood logs. Many insulating bricks will be only a third the weight and correspondingly their strength, of an equivalent solid house brick. Secondly they are very porous so will suck up any moisture (rain) that falls on them or take up moisture from very humid weather. You should seal them really well although that won't stop water getting into the bricks at the bottom of the arch. If it were my oven I wouldn't be using IFB's there.
You can test how absorbant the bricks are by weighing a dry brick then soaking it in a bucket of water for 24 hrs, reweighing it and comparing the two weights. Try the same with a regular solid brick as a comparison.

[Mattias]

There are two problems using insulating bricks for the front decorative arch.

Hi David, thanks for your input. I'm aware of qualities of insulating bricks. We considered this and yet still decided to use them; we had them on hand, and their value as reclaimed material from our old house was worth more to us than the cost of buying (or finding) other bricks. We've used tons of salvaged and reclaimed materials on our outdoor kitchen build, which has kept our costs down a lot! Indeed, we are sealing them well and will keep an eye on them; we don't want any wicking into the cement vent area. I my estimation, some chips and dents will add to their character since they're pretty clean and flush right now. If it crumbles, we'll try something else.

Do you think wicking moisture from the bottom of the bricks will end up in the refractory cement arch face? If yes, is the concern cracking?

[Mattias]

Yes, it is to prevent heat from conducting from the single wall pipe to supports, straps or flashing.

Gulf, thanks for piquing my interest here-- I read a bunch more last night after reading your post. It would have been unwise to penetrate the roof flashing with only a single wall pipe. I found a 24" section of double wall flue and made the swap. Our sheetmetal guy cranked out a beautiful piece of conical chimney flashing that fits the new outside diameter (6.5"). We framed up the enclosure today in a real rain event, and got the dome insulated too. Tomorrow we'll try to get the roof on and start the first curing fire. I'll post some photos once we do that. Cheers and thanks again!

[david s]

Do you think wicking moisture from the bottom of the bricks will end up in the refractory cement arch face? If yes, is the concern cracking?

I'm all for using recycled materials too and as you've built it see how it goes. Redoing the decorative won't be too hard if you have to. Sealing IFB's is a bit of a two edged sword because as well as keeping some of the water out, it also helps to keep it in once it's there. I don't think that moisture in those bricks means they're more likely to crack, the air spaces in the bricks actually allow the passage of moisture more easily, but they will certainly be weaker than dense solid bricks. If your oven is out in the weather it will get wet. We had 191mm in 90 mins a few days ago and I'm giving my oven some fire today to help dry it some. It actually did not get very wet, that only happens when driving rain hits the entry from an angle.

[Thunder Chicken]

Thanks for sharing your build! I am just getting ready to install my 2G90 on my base, and am doing the same style of enclosure as you, Mattias. I have to order the steel studs in as my local hardware store does not stock them, so I am pondering using wood, with all the insulation on the oven, I don't see much of a fire hazard, but maybe i'm wrong!
I hope you can post an update on your project, it is great motivation!