Exterior wall plaster cracks keep reappearing
Thursday, 10 March 2011
One of our readers has a dilemma with plaster cracks that keep reappearing on his exterior wall no matter what he does.
I have been living in a brick and plaster walled house for the last 20 years.
However, some of the exterior walls have what look like small cracks all over the surface. I have repainted several times over the years and even tried applying a universal undercoat as well as a primer, before painting the walls with the final coating
However, after a certain period of time, the cracks always re-appear.
The last time I used Dulux Weatherguard and this has still happened, and in some places, the paint has even started peeling off, so I now need to paint again.
Do you have any advice on how to resolve this problem? Is there any product or process I need to follow to eliminate the cracks re-appearing after re-painting?
I would appreciate detailed steps, if you are able to assist.
Les has some ideas, which he sets out below:Plaster cracks like the ones you describe will have the habit of returning if you just continue painting over them, almost regardless of which paint you use. There is no cheap solution to your problem and not having seen your problem first hand, I can only recommend a course of action that has worked in what I perceive to have been similar situations. I would recommend the following treatment if you wish to do the job once and not have the problem return. The expense and effort will be worth it.
1. You need to scrape and brush all loose paint from the walls.
2. You need to wash the walls with sugar soap.
3. Apply one coat Permabond diluted 3:1 to the walls.
4. Apply 1 coat Duraline Skimrite plaster skim to the walls. (This mixture
is trowelled on and is about 1mm thick)
5. Once dried, sand the Skimrite with a wood block and sandpaper to get rid
of trowel lines.
6. Apply 2 coats Duraline Mattklad (a fibre rich paint with a 10 year
guarantee.) No prime coat is necessary.
I hope this helps.