Tuesday, December 18, 2007

Rumford Fireplace Part IV

Here's a view of the wood cook stove alcove as viewed from the kitchen. Instead of using cinder blocks (parged with stucco) to build the alcove, I decided to use bricks with colors and textures that match our native sandstone. Visible in this picture is the 8.5"x8.5" flue liner for the flue that will be used to vent a possible furnace or hot water heater in our basement. The flue liner barely fit between the back of the Rumford and the back of the cook stove alcove. Behind the flue liner, you might be able to see that I parged the back of the Rumford firebricks with a mixture of (mostly) Perlite and (a little) mortar. I think normal protocol is to leave an airspace between the firebrick and the rest of your fireplace structure, but I figured this mixture could serve the same purposes. (bond break, insulation, and to some degree room-for-heat-expansion.) What the heck - can't hurt can it?

After laying the bricks and stones up to an elevation of 3 feet 6 inches, it was time to fill the entire assembly with concrete and rebar. Mud season is upon us, so instead of ordering a small batch of concrete from the plant, I hauled 44 bags of quickcrete and two bags of straight Portland cement to the house site with my pickup truck. I was going to try it in one trip, but when they put the pallet on my truck and it popped a wheely, I decided to haul it in two trips! Here's the green Ford in my backyard with 28 bags of quickcrete, 6 bags of Type-S, and 2 bags of Portland. Trust me, it didn't want any more!

We mixed the concrete one wheel barrow at a time in the mason's Honda-powered mixer. To every 4 bags of quickrete, we added 2 shovels of Portland cement... just because quickrete never seems as substantial as concrete from the batch plant. Over the course of a few hours, we packed all of the concrete into the house with used drywall buckets... half full thank you please! The picture to the right shows the concrete after it set up in our "stone and brick" form work. I was a little concerned that the brick or stone could blow-out from the pressure of the concrete, but it never happened. We were careful to mix the concrete fairly stiff, and the reality is that by the time we poured the last bucket into the assembly, I'm pretty sure the first bucket was fairly solid under all of it. I laid rebar into the wet concrete as we went, and occasionally, I'd chuck some stone chips or broken cinder blocks into the mix.

Yesterday, we placed the throat on the Rumford fireplace and it fit like a glove. We're using parts and instructions from www.rumford.com to build this fireplace. Our 48" kit turned out to be exactly 49" wide and 46" tall as built. (No complaints with the kit so far, but I would recommend buying fireclay and firebrick from a different supplier - these are truly generic components that can be purchased elsewhere.)

The missing brick in the side of the Rumford is where the ash pan for our bread oven will sit. (hidden by a loose brick of course.) This opening will also allow fresh-air to enter the bread oven, giving us more control over the fire in the bread oven. That's the theory anyway. I can't wait to get the whole structure up to 4 feet, because I can then start building the much anticipated bread oven (also a kit from rumford.com... hmmm... I sure am placing a lot of faith in these folks.) This final photograph is the wall into which the bread oven will be built.

Upon observing the large collection of rocks strewn about her kitchen, my wife commented, "This isn't exactly what I had in mind when I asked for a stone floor." So far, I estimate that this entire structure weighs about 12,000 pounds, not counting the rocks sitting on the kitchen floor! (4000lbs concrete and mortar, 3000lbs brick, 5,000lbs stone.)


Blogger brad_bb said...

Is this fireplace/bread oven/hearth on a slab or is there a basement below?

December 19, 2007 at 6:02 PM  
Blogger oldmilwaukee said...

Good question Brad. The answer is yes to both questions. There is a basement below, but this fireplace sits on a slab that was poured at the first floor level. This "elevated slab" is supported by 18" thick concrete walls in the middle of the basement. These walls bear directly on the footer.

This link shows what is directly under the fireplace


This picture shows whats under that


(the walls with the green rebar sticking out about 4 feet. That rebar was bent over and used to reinforce the elevated slab while tying it to the walls below)

December 20, 2007 at 1:56 PM  
Blogger oldmilwaukee said...

BTW, I wish I had poured a cantilevered slab to support the hearth extension (not yet built) in front of the fireplace. Because I did not plan ahead that far, I must now reverse engineer something to solve the problem. Obviously, the finished wood floor can not serve as the hearth extension!

December 20, 2007 at 1:59 PM  
Anonymous Julius said...

Admire your project.
I'm also the member of this insane
group who build their homes themself.
Also put up a slate roof from 4 colors about 40squares. Finished it
three years ago. All alone, about
10,000 pieces on 11 roofs.
Now I'm installing 50 tons of natural stone in the summers.
Good to see that I'm not the only
one who feels, that this is the way
to build a home.
Good luck for the rest.

January 23, 2008 at 10:54 PM  
Blogger oldmilwaukee said...

Julius, you must be clinically insane as well. I think I'm going to buy a TV and watch it for about 6 months after I get to a point that we can move in. What state are you in? (I mean geographically speaking!) I would love to see some pictures and/or trade notes.

January 24, 2008 at 6:46 PM  
Anonymous Anonymous said...

Quite the undertaking! Would you mind sharing what the pizza oven kit cost? I'm curious how much money would be saved by building it from scratch with masonry.

February 17, 2008 at 5:07 PM  
Blogger oldmilwaukee said...


I'll dig out the invoice and give you the exact amounts. Without a doubt, you could build a pizza oven yourself with firebrick and mortar, but I have been very happy with the kit. I've spent about three years on my house so far, I'm I'm really starting to appreciate the value of things that save a week of head scratching and a week of labor. This pizza oven kit is one of those things.

February 20, 2008 at 9:41 PM  
Blogger oldmilwaukee said...

We've now cooked well over 100 pizzas in this oven and it's still performing great. With that said, this summer we built a pizza oven (in a friend's backyard) with similar dimensions from scratch (using firebrick). It works great too, took more labor, but was cheaper for materials to build.

One nice thing about the kit is that the walls are thinner than anything you could ever build from scratch... which means it heats up with only a small amount of wood, and within less than 2 hours. A "from firebrick" pizza oven like the one we built at our friend's house takes at least 50% more wood and 50% more time to get up to cooking temperature.

September 11, 2009 at 5:05 AM  

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