Hiya, I'm currently constructing an outdoor fireplace. I intend to use 3x3x3/16" angle in a couple of places where I'll need a lintel. I intend to paint it with high temp paint. Anyway, I'm wondering just what sort of clearance I need around the steel for thermal expansion? Obviously I need some mortar in there to hold the bricks together but just not sure of how much of a gap around the steel I need. Thanks very much, jlc
Steel Lintel in Brick?
Feb 01, 2006
12 Replies
You have me confused.
3x3x3/16 is light for lintel iron Lintels carry the masonry load over openings. In order to carry the load, the masonry rests on the lintel. Where does this gap come in?(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net
load it up! once you get to cooking ribs...the tiny bit the steel expands will not matter.
no different than a lintel anywhere else...it's not a consideration.
never worried about any type of clearance on a lintle. mostly used 1/4 inch .lucas
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if you don't confine the ends of the angle, you'll be OK
No matter how conscientious you are about painting that lintel, it will eventually rust. The rust expands, the mortar cracks - I'm sure you've seen it a million times. Since you're doing it yourself and there's a potential elimination of maintenance, have you looked into a stainless steel lintel? It doesn't sound like you'd need a lot, so the premium would probably be under a $100. Is it worth it to you?
RI would also get the stainless steel.
This is for a kiva style fireplace. I'm building an arched opening into the firebox so won't need the lintel there. The damper manufacturer shows two places for a lintel. One is for the span across the opening. The other is up near the top of the smoke chamber to support the flue liner. Their recommendation is the 3x3x3/16". I will have brick on top of this piece of steel as well as at the sides (ie. completely "embedded" in the fireplace masonry). I don't want the mortar joints cracking down the road due to expansion/contraction so was asking how much "air gap" around the steel itself I should use to allow for the steel. Make sense? Cheers, cc
the angle will be completely embedded in the masonry with one leg exposed to the smoke chamber. It sounds as though I should leave a small gap at the ends?
Hmmm, hadn't thought about stainless. I purchased just the standard angle already. We see very little moisure here in NM but I may have to make some phone calls tomorrow to see what a stainless piece will cost. Thanks for the idea! Cheers, cc
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Coefficient of expansion for steel is about 0.000007 per degree F. For brick about 0.000003. For a 300 degree rise, if the lintel is 24 inches long, the total expansion of the steel will be --
TE = 0.000007 x 300 x 24 = 0.05 inches.
The brick will expand about half as much, making the differential expansion about 0.03 inches, totally inconsequential I would think.
Many years ago, my neighbor and I built a brick grill on the property line for joint use. We used imbedded rebar for the grate right above the firebox. Never noticed any adverse effects.
SJF
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Check technical reports there.
I am pretty sure
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technical reports recommend a small gap. The OP can check there.
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