blistered paint external

[claw75]

evening all pick your brains time.....

might be more of a decorating question. looked at job where external paint has started to blister and peel off the render. only 1 to2 foot from ground level..why does this happen? old house listed i think. re rendered about 10 years ago. (not by me..) looks and feels sound. apart from blitered areas.. the one thing i did notice was there was no bell drip and plinth was painted on. the walls being rendered right to the floor. worried they've breached the damp? any advice welcome.. thanks

 

[christ]

its hard to say without seeing, but the way you describe it, i would say it damp, that has risen up the wall, and force the paint to come away from the wall. try porus paint, but wont solve the problem.

 

[bigsegs]

youve just answered your own question mate 10 out of ten...
answer to the problem - disc cutter, fix a batten to the render with sufficient thickness to hold the blade far enough out so as not to slice the bricks in half and use it as a guide...
hack off everything underneath it and apply synthaproof (bitumastic paint) over the exposed bricks...

 

[claw75]

thanks for replies. troweladdict & bigsegs.. wasn't sure if it was the building sweating because it was old. no cavity. wasn't sure if you could inject it, would that cure it.? :-?

 

[christ]

what segs said is your best bet.

 

[bigsegs]

i'll just add that once youve hacked off its a good idea to leave the bricks to dry out for as long as possible, not essential as theyll dry out eventually but painting em with synthaproof immediately will seal the moisture in from that side so the only way it can dry out is vertically or towards the inside...
and dont expect results overnight... it can take months for masonary to dry out properly...
highpressure jetwashing the affected paint off would help... leave that for as long as poss before recoat too...

 

[claw75]

i'll just add that once youve hacked off its a good idea to leave the bricks to dry out for as long as possible, not essential as theyll dry out eventually but painting em with synthaproof immediately will seal the moisture in from that side so the only way it can dry out is vertically or towards the inside...
and dont expect results overnight... it can take months for masonary to dry out properly...
highpressure jetwashing the affected paint off would help... leave that for as long as poss before recoat too...

a fountain of knowledge.. nice one thanks..