4x6 Oven Repair

This British Columbia oven also had a falling arch. Here is the owner's description:

We discovered that the left side wall of the oven was starting to "move outward" about 3 months ago. About a month ago we noticed that the top of the interior arch was starting to "fall" and about two weeks ago I realized that if I did nothing to try and stabilize the arch it would likely get to the point of collapse. the arch had fallen almost 1 1/4" and two rows of pointing had almost completely fallen out as a result of the joints opening up.

I removed the left outer skin of the oven to find that the 3" concrete cladding wall that acts as a buttress to restrain the movement of the arch from gravity and the constant expansion and contraction from heating and cooling had rotated upon it's outer lower edge placing it about 1 1/2" out of plumb.

We used one large 4" hollow steel section (HSS) tube with 3/16" sidewalls to make a giant "C" clamp that was welded to a 3" HSS horizonatl arms that had their bottom edge level with the bedding face of the skew course on the side walls as this course is the one that carries the thrust of the arch.

We then slowly pounded large site built steel wedges down on the left side (having left a gap for this manouver) and were able to force the 3" concrete cladding wall back to nearly plumb. The steel "clamp" went into a high degree of tension bending the opposite down standing arm which we think serves to put mega "spring" into the clamp.

I then crawled into the oven and repointed the two rows of missing pointing with a rich mix of 1 part course sand to 3 1/2 parts of high temperature fire cement as a pointing compound.

We have had numerous regular hot burns since the repair after two tempering burns and thankfully. everything seems to be stable.

Update August 2003

The oven has recently been moved sucessfully and set up in a new bakery. The clamp repair has been 100% successful.