crack in chimney breast

barney150

Hi, I have a crack in the chimney breast running vertically from centre of mantle piece to ceiling. Width at bottom is approx 0.3mm wide tapering out to nothing at the ceiling. Picture attached
There is also a horizontal crack approx 0.15mm wide full width 400mm above mantle piece.
Im thinking it may just be thermal cracking due to the fireplace being constructed wrong. The fireplace is a standard gas fire.

Has anyone seen this before or any views on the cause or solutions?

Thanks
Barney

Kmc123

Gonna jump on the bandwagon here, have a similar problem in my chimney breast which runs legnthways arcoss the face of the chimney breast, appears to be constantly damp in this area too, and knowledge would be greatly appreciated, thanks

sydthebeat

the verticle cracks are very typical of a new build plastered chimney... these usualy are simple plaster cracks caused due to excessive drying out due to the heat from the chimney flues.

the horizontal crack is unusual to me, but if i was to bet on it id still say it was a drying out plaster crack.

The breast looks incredibly wide.. is there a reason for this?

It looks to me like theres a large amouth of blockwork here which is expanding when the fire is on. Thats why the centre of both cracks is approximately at the centre of the chimney breast.... this is the point of highest expansion. Another reason for me to think this is due to the fact that the horizontal cracks dont seem to reach the external corners of the breast...

Whether thats a sign of inadequate parging around the flues im not willing to speculate at this point.

Carlow52

Kmc123 wrote: »

Gonna jump on the bandwagon here, have a similar problem in my chimney breast which runs legnthways arcoss the face of the chimney breast, appears to be constantly damp in this area too, and knowledge would be greatly appreciated, thanks

re the damp, since u posted very little useful detail on ur particular set up, I will dukes of hazzard a guess that there is a crack in the concrete capping on the top of the chimney and the water id running down the side of the ceramic flue as far as the bend in the flue

mrxireland

Yopu can skim over it and out expanded metal to stop teh crack spreading

barney150

Thanks for your comment Syd.
Id like to think its just cracks in the plaster. The chimney breast isn't that wide id say the photo that is misleading. A point to note about the horizontal crack is that it doesn't return at each end, it tapers out to nothing.

muffler

My brace has similar horizontal and vertical cracks and I have put them down to heating/expansion. Part of the plaster came off in the downstairs part of the brace a few years ago when I used a steamer to remove wallpaper and I found that the horizontal cracks in particular followed the line of the blocks.

Nothing to worry about I'd imagine but just to point out that cracks can be caused for different reasons so Im not asking anyone to assume that their braces cracks are as a result of what I identified above.

mrxireland

IS there cracks on the outside or attic where the chimney is ?

barney150

No cracks on the outside and the chimney is external from first floor level. The cracks are just within the sitting room, really whats shown on the photo.
Barney

FixYa

Hi guys.
I am about to buy a house that was built in 1989 and when I went over to see that I have noticed similar crack going vertically from chimney up to the ceiling and continued on the wall in the room above (on the 2nd floor)
Would you reckon is is a severe case of what we have here?
@ barney - did you manage to fix the crack?

barney150

Can you post a photo and ill let you know what i think. In my case I reinspected the chimney, the crack was caused by a crack in the chimney lintel (not called that but the can think of the correct name for it).

Typically these span 600mm but in my case it was spanning nearly a metre, . This lintel had cracked midspan and the crack ran up through the blockwork. I filled in the crack with a standard off the shelf filler prior to painting and it didn't re crack. We didn't use the fire either so I wouldn be surprised if the crack reopened if you were lighting a fire regularly.

Its probably nothing serious, but nice to get to the source of the problem for peace of mind.

FixYa

I will take some pictures when I go to see the house ext time.
I have to add that house does not have central heating and was rented, so I presume fireplace was used all the timme to heat up the living room.
My main concern is that crack cotiunued upstairs and goes vertically on the wall.

A fella called fish

barney150 wrote: »

Can you post a photo and ill let you know what i think. In my case I reinspected the chimney, the crack was caused by a crack in the chimney lintel (not called that but the can think of the correct name for it).

Typically these span 600mm but in my case it was spanning nearly a metre, . This lintel had cracked midspan and the crack ran up through the blockwork. I filled in the crack with a standard off the shelf filler prior to painting and it didn't re crack. We didn't use the fire either so I wouldn be surprised if the crack reopened if you were lighting a fire regularly.

Its probably nothing serious, but nice to get to the source of the problem for peace of mind.

Just out of interest - did you replace the cracked lintel (flue gather) before filling the crack in the masonry?

FixYa

Had an engineer to check the chimney today. He was 80% positive that there is nothing serious.

barney150

A fella called fish wrote: »

Just out of interest - did you replace the cracked lintel (flue gather) before filling the crack in the masonry?

hi, no didn't replace the flue gatherer. Just filled in and all ok so far.