Possible cause of cracks appearing in walls

Troy McClure

Ok, our two story house is 11 years old and was built to A rated standard. This includes 200mm cavity and use of Teplo basalt wall ties (correctly sized).

Last year we noticed some cracks on the gable end of the house, long vertical and a couple of horizontal on this end. Cracks are probably less than .5mm wide. We had 2 engineers loom at it and the jury is still out as to the cause. The foundation conditions seemed find. There are some smaller diagonals under or above windows at other places on the house but nothing like this wall.

Now before anyone starts with talking about defective blockwork, this is a possibility with it been 'early days' if it is, so we have to park that for now. We could pay for block testing, but having spoken to a couple of the companies who do this they recommended to hold off for now or risk getting an inconclusive result.

I am on here trying to examine other possible causes as well. The wall above is not in the main direction of the prevailing weather. There is cracks inside as well, all fairly hairline. On one internal wall between a bedroom and ensuite, there are numerous of these which seems unusual. This upstairs wall would be taking quiet a bit of weight from the roof above.

What I am interested in learning here is to possibly hear from anyone who has done a large cavity or has experience of using the basalt wall ties, that may have experience of similar issues or cracking. The external wall in question had the brickie run out of the basalt ties at attic level and finish the wall above the cold level with regular wall ties, which wouldn't have been much, but it did happen.