Broken One-piece Throat

Buckley Rumford Fireplaces
Broken One-piece Throat
12/1/08

Date: Wed, 25 Nov 2008
From: Jim Buckley
To: Superior Clay
Subject: Broken Rumford Throat
Todd,
Below are pictures of (I think) the first broken one-piece throat. The mason, Tom Lasher, has built about 35 Rumfords in the Spokane area after a career building hundreds of regular fireplaces in San Diego. Now he is an estimator and trainer for Spilker Masonry and also teaches in the apprentice school in Spokane.
The reason I mention that is that Lasher has always thought that there should be an air space around the throat, as with a clay flue liner. So this one, like all the other Rumfords he's built, had space all around the throat with the masonry above the throat supported by a steel angle.
Clearly, from the last picture, the fireplace has been over fired but I wonder if you think the throat would have failed had it been grouted in solid.
Jim
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Date: Wed, 26 Nov 2008
From: Superior Clay
To: Jim Buckley
Subject: Broken Rumford Throat
I believe that the throat is able to absorb and withstand temperature changes when it is grouted solid making the throat part of a larger mass. Probably what is more important is that even if it cracked it would not have fallen out and would continue to work for many years. We are aware of a few cracked throats that continue to function years after the cracks were detected, but they are grouted solid.
Todd