Fireplace Repair

[Matt SD300]

I have a fireplace insert with some cracked bricks (the back of fireplace).

What material do I need to repair the cracked bricks?...thanks

[t walgamuth]

how bad are they?

a few cracks wouldnt worry me much.....unless the cracks opened up a big crack.

if the cracks are big i suppose you could mortar them.

tom w

Fireplace shops sell a special caulk for them.

http://www.amazon.com/exec/obidos/ASIN/B000H5VKE8/nextag-tools-20/ref=nosim

[Brian Carlton]

Speaking of brickwork, I managed to erect a 26' scaffold and repair the 70 year old mortar joints at the top of my chimney.

The process of getting new mortar into old joints is fraught with frustration and more mortar ends up on the roof than in the joints. But, perserverance got it done using rubber gloves and forcing the very wet mortar into the joints manually.

The issue is now the color of the red bricks. The mortar has stained them to a whitish color. I've attempted to put some acid etch on them to no avail. No color improvement.

My next thought is to get up there with a wire wheel on a high speed grinder...........but..........I'm open to any suggestions.

[kerry]

Did you use muriatic acid and a stiff brush?

[Carleton Hughes]

Repointing's a *****,done it on 2 houses.Based upon the advice of a contractor friend I add a vinyl-based binder to the water when I mix the mortar,adheres better,less chance of winter shrinkage and water seeping in and freezing,which is why it falls out in the first place.

[Brian Carlton]

Originally Posted by kerry edwards

Did you use muriatic acid and a stiff brush?

I used the acid etching solution that HD sells......it definitely reacts with the surface of the brick........visible bubbling.........and scrubbed it with a stiff wire brush...........

.........no benefit, surprisingly........

[Whiskeydan]

You should use "refractory mortar" to patch your firebox.
Refractory cements and raw materials are hard, heat resistant materials that are suitable for applications which require high temperature strength, wear resistance, electrical or thermal insulation, or other specialized characteristics. Refractory cements are used to patch or line furnaces and bond bricks or joints in high temperature applications. Most refractory cements consist of a mixture of a binder or clinker and a coarser aggregate.

Muratic acid should clean the brickwork up. Or, time...

I wouldn't wire brush it too much.

[Tomguy]

http://www.ugl.com/ProdTemp.html

I am assuming their fireplace mortar is as good as the furnace cement.

He said it is an insert and the bricks are cracked not a chimney or whatever, talk about over engineering. Fill the cracks with the Red Devil stuff...........done, getting mortar to stick in small cracks inside a fireplace insertwill be almost impossible.

[Brian Carlton]

Originally Posted by MedMech

getting mortar to stick in small cracks inside a fireplace insertwill be almost impossible.

.........getting it to stick in the joints up at the top of the chimney wasn't much easier...........

[t walgamuth]

yeah, i would be careful about the wire brush, too.

i would ask a mason what to do.

you know any that are benz heads?

tom w

Originally Posted by Brian Carlton

.........getting it to stick in the joints up at the top of the chimney wasn't much easier...........

I'm sure of that but he is talking about cracked bricks on a modern fireplace; the bricks are very thin and cracks are inevitable if the fireplace is used and there is no mortar between the bricks I burn wood everyday and have to fix cracks a couple times a year.

The silicate cement caulk is what the manufactures recommend for repair, some even ship a tube with the fireplace.