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| Drawing of outdoor/garden fireplace
Designing a piece can be very difficult and sometimes frustrating as it is, but this particular fireplace presented nontraditional design challenges. Most times a design is conceptualized, put on paper, and the materials needed to fit the design are assembled later, but in this case, the design was determined by what materials were available and budget considerations.
While taking budget and time constraints into account, it was decided that we would use a prefabricated chimney kit made of volcanic rock (pumice) for the firebox itself. This unit established the overall dimensions of the fireplace and dictated much of the overall design. Now that a base and firebox was established (22” w x 26 ¾” l), attention was turned to how designing the smoke chamber and what materials would be used. Clay flue liners (pots) were used to compose the smoke chamber and were cut to fit accordingly. It was at this stage that the idea of adding a meat smoker to the back of the fireplace came about and clay pots were aligned accordingly to produce a flow of smoke that would make this possible. A cast concrete unit that was part of a pizza oven created as a semester project by past students was used as the smoker. The smoker was wider than the volcanic rock base, so it was cut to fit using a 9” grinder and 4” concrete blocks were cut to support it at the back of the fireplace. Concrete blocks were also cut to fit around the clay pots that composed the smoke chamber. Now the internal components of the fireplace were decided upon, attention was focused on the aesthetic appeal of the design.
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Due to the fact that the bricks were of very inconsistent dimensions, it was decided that the faces of the soft mud bricks would be sliced away with the wet saw in order to achieve some sense of dimensional regularity. This decision exposed the beauty of the bricks that had been hidden behind years of accumulated mortar and resulted in a fascinating array of color variations.
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| Working Drawing of the Plan, Side and Rear Elevations |
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| Working Drawing of the Front Elevation and Chimney |
After
determining how the bricks would be utilized, a working drawing was
produced. This drawing established the
design and resolved any mathematical challenges that would be faced during the
production process. It was during this
stage that it was decided that the front elevation of the fireplace would
consist of brick corners on each side and be capped with an arch that is a
combination of jack and segmented arch designs.
These features compose the opening of the fireplace that is 16” wide by
26 ¾” high. The design of the corners
that compose the spring point of the arch was inspired by brick work at the
Manigault House in Charleston, SC. The
brick work exhibited rough tooling created by a masonry chisel, so the decision
was made to have alternating courses of tooled and rubbed bricks which
culminate into a rubbed arch. I feel
that these design decisions complemented each other well and allowed me to add
a few techniques to my repertoire that I would not have gained otherwise.
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| Drawing of Fireplace Opening |
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| Arch Spanning the Fireplace Opening. The Bottom Curve in the Arch will be Created with a Grinder after Installation |
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| Tooled Brick |
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| Rubbed Brick |
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| Actual Brick Corners Underway
Above the arch, a band of bricks with a slight chamfer was decided upon in order to provide a bit of weathering over the arch. This band is composed of rubbed bricks and will overhang the arch approximately 2.”
If I have not mentioned it early, all exposed concrete block and volcanic rock will be rendered at a thickness of approximately ¾” and will provide glimpse of modern contrast to the historic brick composing the other elements of the fireplace.
Progressing upwards on the fireplace, the next design issue that had to be faced was how to deal with the roughly 9” gap between the top of the concrete blocks surrounding the clay pot smoke chamber and the Texas limestone cap that was covering it (Texas limestone was available at the college, so it was used to cap the smoke chamber and delineate the chimney sections). This space was filled by a band of rubbed bricks laid in the sailor position. These bricks required a clean face to be created by using the wet saw to remove much of the mass and being finished with a 5” grinder and spinner. The spinner was used to remove the any existing mortar on all bricks used on this project. Maintaining joint consistency, the sailors will be laid with a ¼” mortar joint. Featured in the image below is the sailor course and render that will be applied to the fireplace.
Chimney designs, including dimensions and aesthetics, were the next components to be undertaken. The design was based around the 8” clay pots that were used for the chimney liner. It was determined that chimney sections that were approximately 16” wide would best accommodate the Texas limestone caps that were being used and would allow for about ½” of stone to be exposed at the base of each section. A height of 18” was established for each section with a stone cap that was 2 ¼” thick. As mention previously, compartmentalization was a major factor in the design process. The chimney sections especially reflect that idea. It was decided that the chimney would be comprised of three sections: (1) a square section at the base (2) an octagon section (3) a circular section. Compartmentalizing the chimney into sections was meant to break it up into independent portions. Each section involved a design process that was slightly different than the ones above or below.
Square Section
The first section was designed as a square of six total courses. Drawing from the fireplace opening, this section would be composed of alternating courses of tooled and rubbed historic brick. The bricks were cut to a length of 8” and a width of 3 ¾” and height that was based on how much mortar had to be removed or brick had to be removed with the spinner to achieve a flat surface for the bed joint. These dimensions provided a joint thickness of ¼.” Since all of the bricks vary slightly in thickness, the bricks will be matched accordingly during the install process.
Octagon Section
Secondly, the octagon section was designed to complement the square below. A template was made to the required dimensions and scribed onto the brick. Once the template was scribed, the bricks were cut using the wet saw. The idea was to have six alternating courses of tooled and rubbed brick like the square section below, but due to the fragile nature of the angled portion of the octagon, it was decided to tool the middle and straight sections of the bricks. As shown in the picture, the tooled portions are aligned down the middle of the octagon with the angled sections being rubbed.
Circular Section
Finally, the circular section was designed. This section was probably the most involved and time consuming. Similarly to the octagon section, a template was made outlining the circle. The template was scribed on the bricks and a straightedge was used to align the saw blade as close to the lines as possible. While all of the cuts were not made with the wet saw, much of the mass was removed which allowed for the spinner to remove the high points and form the desired curves. Again due to the delicate nature of the curved sections of brick, the decision was made to rub these portions and have only the more solid, middle bricks tooled using a hammer and masonry chisel. (After being slowed down considerably by an unforeseen back injury, I owe much appreciation to my fellow classmates, especially Alex Joyce, for aiding in the competition of this section).
The final detail to be sorted out was how to cap the circular section of the chimney. After taking inventory of materials, it was decided that three pieces of limestone that were 4” thick and 8” long would be set off –center with a circular cap on top, would be used for the chimney cap. A template was made for the stone pieces and they were cut using the same process as the circular bricks. Based on the dimensions of the limestone, a circular cap with a diameter of 14” was used to complete this design.
As probably indicated by the pictures, the components of the fireplace are all completed according to the design, but have yet to be installed. Installation will take place at a later date, likely over the summer or during the fall 2015 semester. This project was challenging from a design standpoint, but very rewarding in that it allowed me to build on previously learned techniques as well as acquire many new masonry skills that will be valuable in my career as a mason.
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