Mortar lines showing through blockwork
I had the following e-mail sent to me from my daughter in England and I’m hoping that someone may be able to help with some advice.
I used to be a bricklayer (many years back) in England and had been using insulated blocks since the 70s. I have never come across this problem before despite the timeline.
Her house was built in 1989/90 and has a cavity wall, bricks to the exterior and blockwork inside, standard stuff really. It is the ground floor unit of a duplex. I’ve already warned her off both the thermal wallpaper and, of course, the paint!
Her e-mail below, and thanks for your time to any one who answers.
Have you ever come across pattern staining or ghosting where you can see the mortar lines on an interior cavity wall? I’ve read loads about it and why it happens but wondered if you’ve found a fix? Most people say insulate the cavity wall to bridge the thermal differences but I’m not sure I’ll be able to get that done here!! Others say just redecorate and as its a slow process for the marks to appear (that being fine dust attracting itself to the colder mortar lines over time) that it won’t show for another few years! That or use thermal wallpaper which I really don’t want to do!! I noticed it last year but the line patterns are spreading a bit more now so want to sort really
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