Cracked blocks below window - Help !!

[bivouacboy]

Just replacing our upstairs bathroom and having removed plasterboard from the internal block-wall have uncovered vertical cracks from the cill downwards to floor level.....even splitting one of the blocks in two . The whole section below the window moves when pressure is applied so is very un-sound. Vertical movement seems to be about 1mm or so of the section below the window.....no sign of any cracks in the external bricks/pointing, and there are no windows/doors directly beneath....

The blocks are very lightweight affairs with what can only be described as 'sand' being used for cement ! House is 1993 build.

I suspect since the section of blockwork is loose and I need to bond to it, then it would be best to remove the section (1m2), re-cement, and possibly tie into the surrounding blockwork but could do with some advice.....

 

[masona]

Is it from the corner of the window ? Any picture would help.

 

[bivouacboy]

Hi Masona thanks for the reply - the crack is from one corner of the window opening in the blockwork, vertically downwards - not sure how to get photos to you as I dont have a web-site..........as I say the external brickwork is apparently unaffected, and doesn't look like it has been re-pointed....we have been in the house 7 years.

 

[bivouacboy]

Hi Masona thanks for the reply - the crack is from one corner of the window opening in the blockwork, vertically downwards - not sure how to get photos to you as I dont have a web-site..........as I say the external brickwork is apparently unaffected, and doesn't look like it has been re-pointed....we have been in the house 7 years.

Sussed it

http://homepage.ntlworld.com/mark.reed8/

 

[masona]

No problem there, instead of plaster I would use sand/lime/cement render onto the celcon blocks and finish of with fine finish top plaster. The sand/cement will strengthen any loose blocks.