Interior single skin concrete blockwork wall behind radiator cracked

[Draughtsman]

I have a horiz. crack in the wall, about two thirds of the way up an 18" wide rad that is near the end of the wall.

The crack is intermittently along the top and bottom of a mortar course the full length of that wall (app. 7 feet long). Did the rad cause this?

Should I dig it out and repoint (stitch the new mortar in 50/50 with, say, 400mm stitches) and consider the job as part of the required maintenance inherent in a building that's an amalgam of some quite varied building styles/materials, none of them very recent.

Would it just be easier to take it down and build a new wall, maybe with Thermalites to prevent that wall leeching temperature out of the house thru the floor/exterior walls?

I'm still a bit disconcerted about a rad cracking a wall.

 

[KenGMac]

Dain1, good evening.

Sorry no answers just now, but some Questions?

What age is the property?
I assume the crack is on the external brick?
Can you see any other such cracks around the property? even in any roughcast render that may be on the walls?
has the wall in question been cavity filled with insulation? if so when?

Ken

 

[Draughtsman]

Thank you, but the crack is not in an external wall. The wall concerned is on the ground floor, the small rad is on the other side of the wall toward the right of the photo, more or less where the photo shows the crack along both top and bottom of mortar course.

The original house was an older, thick walled stone built, without cavity but the original building was (circa early 80s) taken down to just below ground floor window cil level and a concrete ring beam installed before building back up with a cavity (both leafs are conc. block). The cracked wall is attached to the building exterior wall (ringbeam visible in image). The crack height is approx. mid ring beam.

In winter that internal single leaf cracked wall is very cold, note that it comes off an external wall (I suspect that the cold just travels across the lower stone built wall/ringbeam and up the inner conc. leaf). The house is also raised up on a plinth at that point, so no ground insulation outside.

No later insulation. 2" of Rockwool was put in the cavities when it was built up from the ringbeam.

There are 2 other longer horiz. cracks on the 1st floor end exterior walls (one is both outer and inner skin) but they are well away from this ground floor interior wall.