dmun's 36" geodesic oven part II

[dmun]

If you recall, the last time we looked at the inside, it was to show the cross section of the insulation, since my oven insulation is done in two parts.



This weekend, I enclosed and insulated the oven on the inside, over the fireplace.

The first thing I did was to mortar in the smoke chamber over the rumford throat. You can see the copper pipe that acts as one of the damper bearings off to the left.



The first layer of blocks. The ones in front of the flue are cut away or thin, and are pressing against the insulation blanket, hence the bracing.



The third layer - full four inch blocks now.

[dmun]

The corners were cut off by patio blocks on the diagonal, to reduce perl-crete use.



Insulating blanket was wrapped around the part of the dome still visible:



I filled the cavity with perlcrete, and mounded it up in the back to fill the arch I made when I cut through the original concrete block studio wall. I figure it can't hurt to have some extra insulation in the building, and it might help structurally if there is more settling or other motion. (Happily NJ is not an earthquake zone, of course neither was New Madrid MO)



Those two block fragments are a form for the concrete: they are standing in for the next section of flue liner.

What it looks like at the end of the day:



The top looks better than the bottom, mostly because I wasn't using random recycled concrete blocks. Still, I'm a long way from producing a finished concrete block wall. This one is going to be covered with ceramic tile or something.

[icj]

Thank you for your careful and detailed photographic log of the construction of your oven and fire place. Reading through the posts and watching the development is intoxicating, like reading a book way too late into the night, but you can't quite put it down. But unlike the book there are chapters yet to be written, so may I offer my humble respect and encouragement and say I can't wait for the next post. May my own oven look half as good.

p.s. It is a pity that you have to cover up that beautiful dome with insulation, at least you can see it from the inside.

[dmun]

This weeks work gets pretty perepheral to oven building, but I'm pretty much committed to documenting the process from start to finish. As you know, my oven is being built into the wall of my workshop. There is a masonry first story and a ceder and shingle finished gambrel roof second floor. This week I build a wood frame tower adjacent to my second floor.

The process starts with a sill plate. Did you know that code demands that any wood in contact with masonry be pressure treated or flashed? So, here's my 2 x 10 PT sill plate.



The slot is for clearance to combustibles. You will notice that one of my anchor bolts fell in the middle of same slot. I needed to make up that little aluminum clamp to hold down the sill plate.

Anchor bolt placement needs to be planned at carefully as anything else. More later.

The spaces between the corbels were fitted with PT nailers,



to attach pieces of crown moulding between them.



The bottom of the roof was cut away, to plan for the construction of the wall units.

[dmun]

I built the wall units on the ground, with the plan to hoist them up to the second floor. Here's the front unit.



You notice that there is a careful cut on the inside of the wall to keep the wood away from the chimney by the required two inches. Notice anything? Yep, my chimney is on the other side. I had to disassemble this and put it together backwards:



Here's the outside of the left wall unit:



and the inside:



There is a clearestory window framed into the top of this side, which is on the south side of the tower, to let light into the tower all day long.

[dmun]

A note on the framing: My tower is built from re-purposed timbers from someone's demolished carport, which I picked up on craigslist. Mostly what looks nasty is peeling paint. It will all be covered up. Doing my bit to keep trees standing and landfills from overfilling.

Cutting into the roof on the outside:



and the inside:



The temporary skylight:



The rafters in the middle were removed, and moved to the side to form double framing members on the sides of the opening. Here I'm lag-bolting the two rafters together:

[dmun]

The big day for tower assembly arrived on Saturday. Would that I was better prepared, but life is like that. My rule-of-two on major projects is that everything takes twice as long and costs twice as much as originally anticipated.

Here's friend Chris helping with the tower assembly:



You'll notice that clever lift from the rental place. It's simplicity it's self, and it will lift a lot. Those units were hard even to stand up, let alone lift.

Everything looks better in the morning.



I was talking about careful planning on bolt placement: Here's a stud neatly pocketed to accept the nut in the wrong place:

[dmun]

Here's a shot of the tower with the wall framing finished,



A little tree dappled morning sunshine never hurt anyone's looks.

Here's the sheething in progress. Sheething is not my favorite job.



Note that the sheething really adds to the stability of the structure. Even with those massive timbers, and being screwed together, the tower was pretty wobbly until the sheething went on, now it's as solid as a rock.

A photo note: If you go to the FB photoplog and you look at the images there, double clicking on them will bring up a larger version. What you see in the text are semi-thumbnails. Alternately, you can right click "open in new window" and replace "medium" with "large" in the URL, and see the full size image.

[james]

As always, I can't wait to see how this comes out. Is it going to be brick? Do you have a decorative pattern?

It would be fun to see the chimney in the context of the house and the roof line. I'll bet this is going to be a great visual element for the whole house.
James

[dmun]

First, to answer James' question, the top part of the tower will be covered in cedar shingles, which was a very typical construction technique at the turn of the previous century - masonry or clapboard on the first floor, and cedar shingles above. Note the flare at the bottom of the chimney, with the crown moulding below, all very much in keeping with the local construction details in the neighborhood.

Here's the tower wall sheething complete:



That little sub-roof behind an obstruction? It's called a cricket. If it's behind a chimney, as it almost always is, it's called a chimney cricket. You can file that with the useless trivia in your mind, like that the name of the cop and the taxi driver in "It's a wonderful life" are called Bert and Ernie.





The purpose of that detail is to route water and snow melt around the tower rather than into it.