Building the kitchen Stove

Traditional ‘Polish Stove’ ( fireplaces) are differentiated from typical European fireplaces by their tall/shallow firebox, their streamlined throats, and most importantly… by their promise of actually producing more heat than they waste! They are designed to maximize the direct and reflected radiant heat from the fire in to the Cooking Cells, central heating stove and the water heater heating boiler that heat the house on cold days.

Having a genuine desire to build our own functional fireplace, but possessing no real knowledge of proper fireplace proportion and design, we decided to buy a 48″ kit from Superior Clay Corporation. In exchange for our money, they shipped to Przesieka: a lot of firebrick, a refractory throat, a two piece clay smoke chamber, a cast iron damper, clay flue liners, refractory mortar, and instructions for building our own fireplace. Everything arrived promptly and in perfect condition. Most of the “magic” for getting the proportions (and draft) correct seems to be in the design of the throat.

After reading the directions, drawing dimensions on our slab, dry-laying some bricks without mortar, and checking the dimensions of our unmortared hearth with the dimensions of throat, we ware  ready to mix mortar and put the hearth together. This step was fairly trickey. We mixed the mortar fairly wet (looked like cake icing), buttered the bricks, and squeezed them into place one at a time such that the joints were 1/16th to 1/8th of an inch apart.

This particular refractory mortar “sticks” the bricks together within a few hours, but takes a long time to dry. At a few points we was unsatisfied with our work, so we pulled the offending bricks back up, scraped off the mortar, applied new mortar and placed those particular bricks again. No pressure to hurry. In fact, the mortar was easy to wipe off – even some hour later, so it was OK to be sloppy as well.

The back of the Rumford style firebox has a flat side and two angled sides. At first we thought we should weave the brick courses of the three sides together for strength. But then we realized that the kit (no matter which size you buy) is thoughtfully designed to use exact full-brick and half-brick increments. We also realized that in order to weave the bricks together, some would have to be cut on a 45 degree angle, which would leave a thin sliver of brick that might be more prone to breaking or spalling. The full-brick-halfbrick design suggested in the instructions is about the best you can do, aesthetically, without going to something like a herringbone pattern. Ultimately, it seems that these firebricks are more of a “liner” than a structural element of the Rumford fireplace kit, so we have no qualms about laying up the three sides of the firebox separately. The trick to laying these bricks seemed to be… keeping the courses level, keeping the courses straight, and keeping the joints a consistent thickness.

Here’s where we decided to deviate from the instructions – slightly. Although not specifically mentioned in the printed instructions, the book for the rumford kits suggests that you might want to pour your fireplace structure, rather than lay it with block. This is the route we have chosen. Of course, concrete at anything over a few inches thick, has some incredible force pushing outward while it is in liquid form.

We have decided to pour no higher than 2 feet at a time, and we will “kick-off” or otherwise support this brickwork when we pour against it. The book also advises to make provisions for a bond-break (or even better – an expansion gap) between the firebrick and the poured cement backing, if you chose to pour cement. More on that when we get to it. For the conventional block fireplace route, see the instructions on their book.

Here you are looking at the only brick we have ever laid in our life. I’m proud of it so far! 5 courses of brick (laid on edge – these are called “shiners”) equates to about 2 feet of height. The fire-box will eventually be 10 courses high – or nearly 4 feet tall, before the throat is mortared on top. In the bottom of the hearth, you can see we have left one brick out (and a hole beneath the hearth) to serve double duty as a “fresh-air make up” / “ash dump.” Perhaps we will make or order a trap door set-up for this hole. In the mean time, a loose brick will serve the propose.

In the left of the last picture (and in the right of the second-to-last picture), you can see a partial 36″ bread oven kit – from the same manufacturer. The bread oven kit (aka wood fired pizza oven) is just sitting there now so that we know it will fit when we bring the entire masonry structure up to about 4 feet and start incorporating it with the fireplace. I’m more excited about the bread oven than we am the fireplace (Alma is a great cook!), so we’ll be sure to document its construction as well.