On 10/11/16 19:10, Phil L wrote:
RMann wrote:
Hi everyone,

We would appreciate some advice on the below issue:

There are cracks apearing on some if the walls through out an area of
the house (internal) and I need to asatain if there is a serious
problem. When I recently had a small room upstairs re plastered I noticed
there was some decay upstairs between the iner suporting wall and a
small gap between the iner and outer wall.

Not very clear.

do you mean there is a gap where an internal wall meets an external wall? -
if this is the case then there's a serious issue here. The external wall is
moving away from the internal walls - the internal walls will stay where
they are when the external walls start to fall over....also it's unlikely to
be wall tie failure as mentioned elsewhere - when wall ties fail, the
external leaf of brickwork parts company with the internal leaf, that is,
the cavity gets wider, the internal leaf of the outside wall doesn't
generally move away from the internal walls.

I've seen it happen once - in the house I grew up in. My bedroom - the
solid double brick external wall moved slightly away from the
breezeblock inner wall and opened a gap of about 1/2".

My dad cleaned it out, stuffed it with 3:1 mortar and plastered over. It
never moved after that. Not saying the mortar was holding it - just that
it was probably a one off slight movement that found its new position
and was happy after that.