Fireplaces & Chimneys **PICS*

[thiambal]

Perhaps you could all put your fine minds to these problems.

The combination fireplace in my lounge



Has a verticle crack in the centre of the firebrick which is getting worse. This pictures makes it look better than it is. I would say it is between 1-2mm wide



Can I patch this up with fire cement (how effective is this likely to be) or do I have to replace, if so where do you get replacements? Will I have to take the whole fireplace out (not keen!! in my freshly decorated room).

Also the fireplace has sustained some damage at some point and I am bit concerned about what will happen if I have to take it out. Any thoughts?



And then there is the chimney. This chimney is from the other room and is not currently being used, but we are going to start using it soon. It has been smoke tested and it was fine, but the there appear to be some gaps in the mortar and a couple of the bricks have turned to powder. Should I bother re-pointing? And how should I tackle the knackered bricks? Will it be ok to scrape out the rest of the soft brick and just mortar another one in?

 

[Lime]

I would leave the crack.
As long as the firebrick is generally whole and not exposing metal behind it the crack will do nothing but release tension caused by heat expansion and contraction.
Filling the crack is likely to act as a wedge and open it up more.
Usually this type of crack is caused by "hot" fires and the over-energetic use of the poker at some time.
It is unlikely that you would be able to get a suitable replacement although you could be lucky.
Removing the fire should not be contemplated for such a minor problem.

The chimney is fine.
Don't remove and replace the bricks.
Removing the bricks is much more likely to cause further problems with the rest of the stack.
The gaps in the mortar are very slight but can be filled if you wish.
Just make sure the water that once came in down the bricks is prevented from doing so again.

 

[thiambal]

Cheers lime,

The water marks on the wall are historic, although there is a leak elsewhere on the roof that is about to be fixed at great expense.

As for the firebrick, I am just concered as it seems to be getting bigger - i.e. a year ago when we moved in there was a closed crack and now it is open by 1mm - 2mm. Perhaps I will leave it and see if it gets worse. I take your point about expansion of the fireplace - I guess this is probably what caused the crack in the first place

btw, how do you prevent a hot fire?

Can you really not replace fire bricks? I would have thought they have a finite life - what do you when they finally bite the dust?

 

[Nemesis]

They do have a finite life - burn away eventually.

If you can, see if you can find a thin freestanding one to place in front of the existing to protect it.

 

[thiambal]

Good idea Nemesis!

Any idea where you might get one?

 

[Nimster]

Try Ebay. You can get most things on there

I did a quick search for fire brick and it found a few.

 

[thiambal]

Ah ha, this suggest you can replace a brick without removing the fireplace

http://cgi.ebay.co.uk/FIRE-BRICK-OPEN-FIRE-WOODBURNER-STOVE-LINING-FIREBRICK_W0QQitemZ180073118368QQihZ008QQcategoryZ38222QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

What do people think - is this possible.........

Obviously I will keep the original until it is well and truly knacked - but this seems like a cheap and simple solution!!??

 

[Nimster]

Hi

We had these in our last (open) fire. We bought them as the fireback was starting to look poorly and had the beginnings of cracks. It stopped the fireback getting any worse.

We currently have them in our log burner, more as a volume reducer though.

Definitely worth getting as they should stop the cracks getting worse. You should also be able to get them from any shop that sells fireplaces/surrounds - particularly one that does repro and refurbished originals.

Should have said, we just sat the bricks inside the fireback. We didn't try to remove any parts as the bricks we bought were small enough to fit inside the existing space.

 

[thiambal]

I think I will do this Nimster, perhaps cut one down to 1/2 inch so that it does not take up too much space

Does anyone have any experience of using this to physically replace the original firebrick without removing the fireplace?

 

[Nemesis]

My mother has a fire like yours, with a crumbling fireback.

I am sure there must be a way of removal and replacement, but as yet I don't know how, considering the infill at the back, and the removal of the whole thing is not an option!

She has kept hers going for many years by placing a firebrick in front - those new fangled ones look interesting I have to say.

 

[thiambal]

They do look intersting, I have an old fireplace in the back garden that someone removed from our house at some point. It is is remarkably good nick considering years in the garden (cannot put it back as there is no chimney breast anymore).

Importantly, it has a firebrick, I will see how this one goes in and see if it look practical to replace without removal from wall.

Watch this space for a full report.

 

[Lime]

btw, how do you prevent a hot fire?

That's easier said than done because there are so many variables.
Weather conditions, the fuel burnt, how often the grate is cleaned out, how much the fire is raked through etc.
IME Welsh anthracite was the worst for a hot fire because it was such a good fuel. However I don't think you can still get it.
Try not to bank up the fire to get more heat out of it and leave a little ash at the back to act as insulation.
However, as has been said, the firebrick has a limited life. The ones we see now in old fires are still here because the fires haven't been lit much in their lifetime.

Many fireplaces should not need to be taken out to replace the firebrick but how it comes out varies a lot.
Some come out if the fire bars and grate are removed, some clip on behind metal lugs, some just have to be lifted up.
The trouble is like in so many fires the metal and firebricks distort after time and ash gets in between the gaps so the firebrick gets really wedged in.

 

[Nemesis]

Yes, Welsh anthracite is still obtainable, as is Alston Anthracite.

http://shropshiremines.org.uk/bmd/ayle.htm

 

[worms]

Ah ha, this suggest you can replace a brick without removing the fireplace

http://cgi.ebay.co.uk/FIRE-BRICK-OPEN-FIRE-WOODBURNER-STOVE-LINING-FIREBRICK_W0QQitemZ180073118368QQihZ008QQcategoryZ38222QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

What do people think - is this possible.........

While this may be a good solution for an open fire, I have my doubts about it for a wood-burner or any other enclosed stove. The fire bricks are surely an important store of heat - without them the stove cools rapidly. If you replace the brick with an insulating fibre board, less heat will be transfered to the cast iron and since it is not being retained by the brick and has to go somewhere, surely more of the heat will simply go up the flue?

 

[Lime]

I think you have a point worms.
The extra insulation may well change the transfer of heat from the fire to the room.

Your mention of cast iron reminds me also of the extreme danger of that metal getting red hot.
For those of you who don't know, when cast iron is red hot (literally) it has the property of allowing carbon monoxide from the fire to pass or diffuse through it into the room.
A very important function of the firebrick is to protect the cast iron from damage and getting too hot for this reason.

 

[thiambal]

I am losing you a bit now lime.

Would this replacement board in an open fire cause a danger of the cast iron getting red hot? Or would this only be a problem in a stove?

 

[thiambal]

And then there are real clay ones like these

http://www.thefiresideshop.co.uk//category-6272/product-4570//BACK-BRICK-No1-FSBACK1.html

in different sizes.

But I am not convinces of the likelyhood of them slipping neatly into and old fireplace. The existing brick is narrower at the top than bottom for one thing.

 

[Lime]

I am losing you a bit now lime.

Would this replacement board in an open fire cause a danger of the cast iron getting red hot? Or would this only be a problem in a stove?

I wouldn't worry about an open fire.
Nearly all the carbon monoxide produced in an open fire will be converted to carbon dioxide.
The problem of cast iron getting red hot is not common fortunately and only really applies to enclosed fires that control the fire by reducing it's air supply.


I assume that some people contemplating buying this board for their stoves may have defective or badly damaged firebricks and could be tempted not to replace them and think it doesn't matter.

 

[Lime]

And then there are real clay ones like these

http://www.thefiresideshop.co.uk//category-6272/product-4570//BACK-BRICK-No1-FSBACK1.html

in different sizes.

But I am not convinces of the likelyhood of them slipping neatly into and old fireplace. The existing brick is narrower at the top than bottom for one thing.

I think that you are right. They would not fit directly into most old fires.
However perhaps it might be possible to shape them using an angle grinder with suitable blade?