chair brick.

[desrob]

what your feelings on these ,how are you suppose to check the builders opening and is behind them meant to be filled up to certain level as with solid fuel,the reason i am asking i came across one with cracks in it and i wondered if they can be repaired without removal.

 

[tamz]

Behind is supposed to be filled up. If it is not filled the easiest way will probably be with vermiculite mixed with cement 6:1.
If the fire brick are cracked you may be able to repair using fire cement but prefferably cut them out and replace.

 

[GrahamM]

These should be filled in behind right to the top of the opening so any holes etc in builders opening will be made good. If it is not filled you have know way of knowing what is behind so will be 'AR' until sorted as per tamz post.

 

[desrob]

i have removed several of these and i've not came across one that has been filled up behind it,

 

[GrahamM]

Any pics?
Think some confusion over terminology.
Some fires have a fixed chairbrick that is not removable so this should be backfilled, filling any voids. Most of fires I come across are fitted with a firebox/chairbrick that is removable for inspection. So the builders opening behind should be completely void of any holes/cracks. I defended BG a few days ago in another post, but I have lost count of the number of BG serviced fires I have attended where upon removal of firebox I found all sorts behind.