Two years ago, I emulsioned my Lounge, hall, stairs and landing in the same colour using B&Q's own ivory matt. Most of the stairs and landing now looks horrendous. There is large scale cracking that looks like crazy paving. The size of the paving is about 25mm and fairly consistent. It is getting worse by the week although it started about a year ago after it had been done a year or so. In the bedroom it has started although not nearly as bad. In places up the stairs it has started to bubble and lift away from the wall. Some of the crack lines are perfectly vertical and yet another pair of lines follow exactly where the premoved old dado rail was. Previously, the walls were de-papered, leaving part bare plaster(in good condition) and part previous old emulsion which was lightly sanded to try to achieve a more uniform surface to take the new emulsion. When finished it looked wonderful. Now it looks like a pig's ear and will have to be done again. What did we do wrong? Was it cheap paint? Lack of prepping? Global warming? Hoping someone can put me right as I don't want to have to do it all over again in another 2 years.
Glyn