Part of our property was built in 1860. The whole of the external brick work was painted about three years ago by the previous owner. I have noticed that that there is a small section of exterior wall under an upstairs window (about 1 square metre) where the pointing appears to be bubbling under the masonry paint. The bubbles vary in size up to about 3mm in diameter, seem fairly solid but crumble when pressed revealing the mortar as crumbling. Some bubbles have evidence of very slight fungal\moss growth. The bubbling is isolated only to the pointing and not the brick face. I cannot see any obvious evidence of water leaks and internally all seems okay with no signs of damp.
I know I will have to rake out and repoint but does anyone know what this could be and the cause and any special considerations? By the way I have no idea how old the pointing is what type. Pictures are attached.
Thanks
I know I will have to rake out and repoint but does anyone know what this could be and the cause and any special considerations? By the way I have no idea how old the pointing is what type. Pictures are attached.
Thanks