Mould in Bungalow

[bezzapebo]

I live in a detached bungalow. We moved in about 14 months ago, and the house had been empty for 2 years. After about 2 months or so, we noticed that some of the walls were quite damp, and black mould was growing inside. We were advised to put in airbricks, which we have. We have not decorated in case it came back - and it has, but on a different wall! Again, we have put a further airbrick in. I have been advised that it may well be that in between the layers of brick, a lazy bricklayer may drop some mortar/cement, and not remove it, thus blocking the airway between the two layers, and causing dampness, and mould to grow. Is this possible? Also should I use silicone proofing to help with this problem. I really want to get on with my decorating now, but I am worried in case this problem happens again.