Question concerning Firebrick in woodstove

[GeriatricGinger]

Replacing all the brick in my '87 Tremont/Vansco. Side brick is 4.5" x10.5" x 1.25". Many are cracked/broken.

All I can seem to find are 4-1/2 x 8-7/8 x 1.25. One place told me to cut a brick to fit the extra length needed to complete the side, then cut bottoms to fit between side brick and shaker grate..



Crude drawing, but inside of firebox, black on top is angle iron retainer for top of brick
Red line denotes where the 2 pieces of brick would come together/meet for the wall-sections. Then floor brick would hold small lower section in place.

How/what would keep the two pieces vertical, aside from gravity alone? Doesn't seem right, in my head.. basically, the two vertical pieces would meet about 1/4" above the floor brick..


Suggestions?

 

[begreen]

Can the side bricks sit on top of the bottom bricks? That would boost the height to 10.5".

 

[GeriatricGinger]

Can the side bricks sit on top of the bottom bricks? That would boost the height to 10.5".

I thought about that, as well.. but I guess my concern would still be present, with "what would keep the bricks in place?" Originally, the side brick was held in my the floor brick at the bottom, and the angle retainer at the top. Using the method above (where the side brick sit on TOP of the bottom brick, there's no retention..

 

[WoodyIsGoody]

I thought about that, as well.. but I guess my concern would still be present, with "what would keep the bricks in place?" Originally, the side brick was held in my the floor brick at the bottom, and the angle retainer at the top. Using the method above (where the side brick sit on TOP of the bottom brick, there's no retention..

If you're using a tile saw to cut your bricks it's a pretty simple matter to put a slight back-bevel where the upper bricks sit on the top edge of the lower bricks. As long as the lower wall bricks are held firmly by the floor bricks you probably don't even need to do that.

 

[WoodyIsGoody]

Using the method above (where the side brick sit on TOP of the bottom brick, there's no retention..

Retention from what? Short of an earthquake I can't think of a force that would cause them to come out, the force would need to come from behind the brick. Firewood banging against them is just going to push them tight against the steel wall.

 

[GeriatricGinger]

If you're using a tile saw to cut your bricks it's a pretty simple matter to put a slight back-bevel where the upper bricks sit on the top edge of the lower bricks. As long as the lower wall bricks are held firmly by the floor bricks you probably don't even need to do that.

Ok thanks. Yes, I'll be using a tile saw.

Retention from what? Short of an earthquake I can't think of a force that would cause them to come out, the force would need to come from behind the brick. Firewood banging against them is just going to push them tight against the steel wall.

Well, Woody, I've watched my wife throw wood into it, and it is, indeed, nothing short of an earthquake.. I guess she thinks she'll fall in if she stands too close, I dunno.

Anyway, I thought I'd ask the more knowledgeable before giving this method a go.

Thank you all for responding and assuring me it'll be ok to do it this way.

 

[coaly]

Be careful until the ash packs between them. That makes them quite tight. Ash also packs behind them pushing them out.
The original Fisher design in the first stoves was to weld brick clips at the top of the side bricks setting on top of the bottom bricks. It didn't work well allowing bricks to break from shipping and use. Most fabricators lowered the brick clips and installed the sides first using the bottoms to keep them in place.

As Woody suggested, I would angle the bottom of the upper course to match the angle of the lower course so the bottom course held in by the bottom bricks won't allow the top to kick out.

If the bottom doesn't fit tight enough to hold them tightly, pry the bottom bricks apart adding ash between them and pack tight. It makes them very solid. It will do that on its own in time.

Install the back first so the sides hold the end rears in place, since the back takes the brunt of being hit loading.

 

[GeriatricGinger]

As Woody suggested, I would angle the bottom of the upper course to match the angle of the lower course so the bottom course held in by the bottom bricks won't allow the top to kick out.

Install the back first so the sides hold the end rears in place, since the back takes the brunt of being hit loading.

Ohh.. Woody means like this? I think I initially misunderstood the 'beveled' cut..
(side note: short of grinding, is there a 'smarter' way to remove the gasket adhesive from the doors to replace the seals?

 

[coaly]

Yes, that will lock it in.
The only thing is, that is harder on a masonry blade cutting them completely through. The bricks are much softer than a normal building brick. You normally score 1/8 to 1/4 inch and snap them easily.

If it were something that you couldn't cut shorter, or wanted to use upright bricks on top of the bottom layer, drill holes with masonry bit and pin together with steel rod or bolt shanks with head cut off. ( one pin per brick is plenty) In your case where expansion is an issue heating steel, the hole would need to be drilled a bit deeper for the length to expand when hot. Pin side brick to bottom on 90* angle and install sides connected to bottoms. Finish laying bottom bricks in center. Think retaining wall or foundation with rebar to pin together for lateral strength.

If the gasket material was installed with gasket cement, a wire wheel in drill takes it down to bare metal.

 

[WoodyIsGoody]

Yes, that will lock it in.
The only thing is, that is harder on a masonry blade cutting them completely through. The bricks are much softer than a normal building brick. You normally score 1/8 to 1/4 inch and snap them easily.

Using a wet tile saw and diamond blade you could cut firebricks for hundreds of woodstoves with one blade. Blade cost would amount to pennies/stove.

 

[WoodyIsGoody]

Ohh.. Woody means like this? I think I initially misunderstood the 'beveled' cut..
(side note: short of grinding, is there a 'smarter' way to remove the gasket adhesive from the doors to replace the seals?

That might work too but, depending on how tightly the lower course is held by the floor bricks, I can also see potential issues. I really think you should try it with no bevel first. A long as the second tier is above the ash level, I don't see an issue with relying on gravity. But my initial thought was to simply back-bevel the shorties the same direction as in your illustration (but only 1/8 as much, about 3 degrees) and leaving the upper bricks square. True, this won't positively lock them in place like your drawing would but it will insure the tops of the upper course stay tight to the back wall (and avoid the issue of the joint between the two courses potentially buckling outward).

Gravity is amazingly reliable so I would try it with no bevels first. And the more I think about this, the more I second guess my initial idea to put the bevel where the two courses meet. If corrective action is needed it will depend upon what issue crops up. My guess is it won't be necessary. But a back bevel of a few degrees on the bottom of the bottom course could discourage the tops of the shorties from extending away from the back wall.

 

[GeriatricGinger]

I do have a wet tile saw with diamond blade (last job in the house was cutting glass backsplash for the kitchen..)

Thank you all for the information and education. I never thought of pinning them. Of course, I'm probably overthinking this whole "problem".

 

[coaly]

Using a wet tile saw and diamond blade you could cut firebricks for hundreds of woodstoves with one blade. Blade cost would amount to pennies/stove.

Back then, a circular saw with masonry blade was used. Same as building a house on a job site using a masonry blade in a circular saw for cutting cement blocks, bricks, and full size firebrick for fireplaces. They wear more than a diamond wheel but many people don't have more expensive tile saws or diamond wheels in angle grinders. Anyone with a "Skill" saw can cut them with a masonry blade easily. Using that type of cheap blade, you get far more cuts scoring the bricks.

 

[WoodyIsGoody]

They wear more than a diamond wheel but many people don't have more expensive tile saws or diamond wheels in angle grinders. Anyone with a "Skill" saw can cut them with a masonry blade easily. Using that type of cheap blade, you get far more cuts scoring the bricks.

I guess I was thinking tile saw because that's what the OP said he was using.

 

[georgepds]

You seem like a DIY... why not cast fire brick to the size you need?

http://www.traditionaloven.com/tutorials/concrete.html

Mix the appropriate concrete.. make a mold to the size you need by screwing wood sides onto plywood base