How to Bond Facade Brick to Firebox

[MoeMan]

Hey All,

Although not in construction these days, I grew up in the business, I've done some masonry work in my past, and tend to do most work myself because I typically can do it at least as good if not better than the pro's. For my chimney work, however, I was going to hire it out. I think the pros have some specialized knowledge and I just didn't feel like bothering with it. Come to find out there's a 6-month wait for any appointments. So... I tried, but I'm back to doing it myself.

I have all of my issues resolved except for one - the interior brick facade is gapped to the firebox by 1/4"-3/8" including the lintel. Sticking a pry bar in the gap you can pretty easily move the entire surround. It's primarily being held in position by the wood surround. I don't want to fill the gap with mortar since it will be tough to get it far enough back to bond the entire brick. I was thinking of pumping some sort of a sealant or adhesive into the gap to create the bond, then filling the gap near the face with refractory cement.

Any suggestions on how to fix this? Whatever the fix, I'm not willing to pull all of the wood off until the room is up for a remodel, and that's several years away.

Thanks, all...

 

[EbS-P]

Hmmm. High temp silicone??? What is your main concern? Keeping it from falling off?

I’d explore some mechanical means. Two counter sunk tap-cons into something solid would do it.

Heck I would be tempted to weld a strap from the lintel to the damper frame. Yes I know welding cast is not a good idea but I’ve done it twice for quick fixes. I got my pieces to stick. Harbor freight 125$ flux core welder. A little pre heat.

Edit.. a box fan on top of the chimney would make a decent fume hood if you are concerned about where those fumes are going.

It just doesn’t seem right that the lintel is not supporting anything but the facade. I’ve only ever looked at my two fireplaces so I’m not any source you should rely on.

 

[MoeMan]

Hmmm. High temp silicone??? What is your main concern? Keeping it from falling off?

I’d explore some mechanical means. Two counter sunk tap-cons into something solid would do it.

Heck I would be tempted to weld a strap from the lintel to the damper frame. Yes I know welding cast is not a good idea but I’ve done it twice for quick fixes. I got my pieces to stick. Harbor freight 125$ flux core welder. A little pre heat.

Edit.. a box fan on top of the chimney would make a decent fume hood if you are concerned about where those fumes are going.

It just doesn’t seem right that the lintel is not supporting anything but the facade. I’ve only ever looked at my two fireplaces so I’m not any source you should rely on.

Primarily I want keep smoke from getting in behind the brick, and hence the mantle. If I just mortar the gap, I expect it will crack pretty quickly since there's no bond between the face bricks and the firebox bricks. The two probably experience some relative movement as temp and humidity changes.

The lintel does just hold the face bricks. However, if you look closely at the damper you can see that it has a lintel incorporated into it. Apparently two completely independent systems which were once mortared together but since separated.

I have an arc welder, so I'd be able to give that a try. An easier consideration I had, as you also mentioned, flat steel straps at four points, top bottom left and right, tapcons to fasten inner to outer. Too hokey?

 

[bholler]

Primarily I want keep smoke from getting in behind the brick, and hence the mantle. If I just mortar the gap, I expect it will crack pretty quickly since there's no bond between the face bricks and the firebox bricks. The two probably experience some relative movement as temp and humidity changes.

The lintel does just hold the face bricks. However, if you look closely at the damper you can see that it has a lintel incorporated into it. Apparently two completely independent systems which were once mortared together but since separated.

I have an arc welder, so I'd be able to give that a try. An easier consideration I had, as you also mentioned, flat steel straps at four points, top bottom left and right, tapcons to fasten inner to outer. Too hokey?

Just fill it with mortar

 

[esquid2]

How about Simpson helical ties to connect them (and then use high temp silicon)?