Winter paint cracks

[Driver6452]

Hello everyone, just joined DIYnot, need some help with this one, every year about this time when it gets very cold a couple of small areas of Dulux matt emulsion starts to crack just a little, the house is 3 years old and all painting done by Bellway homes, every year since it was new I have sanded these areas down re-painted and within 3 days cracks reappear I repeat this task maybe 6 times before I turn a blind eye, and they`re here again, rest of the house is fine, and over the years done my share of painting but even using bullseye 123 still cracks appear but not as bad, its a upstairs bedroom using new Dulux matt emulsion and I let it dry for a day before a second coat, was thinking of using a 50/50 mix of matt with water as a primer this time, as a friend says it could be the plasterboard drying the paint out, dont want another winter sanding and painting these areas, so a solution would be great, thanks in advance. Mark.

 

[Richard C]

As for the cracks; what type of walls do you have, stud or brick/plaster? Do the cracks appear in the same place every year? Do they follow a straight line or are they random? Are they hairline cracks or, say, around 1mm wide? Internal or external walls? Are there any doors/windows near by? Sometime a few pictures help.

It’s unlikely to be anything to do with the paint. Cracks tend to appear more in winter time & are generally nothing to do with it being colder, more to do the central heating being on; this lowers the ambient moisture content of the building & everything starts to dry out & shrink. Some cosmetic cracks in any property are inevitable, it's a consequence of the very materials they are built from.

 

[Driver6452]

Thanks Richard the walls are plaster internal same place each year hairline cracks following the same path and there is a couple of rads in the room never affects other rooms when lightly sanded they`re gone but reappear when painted with paint thats always fine anywhere else in the same room or other rooms in the house must do it 6 times per year and into the 4th year now!

 

[Richard C]

Have you tried raking the cracks out? Rake out to around 5mm deep (or at least deep enough to get through the layer of finish plaster), re-fill & see what happens; spray a little water into the crack before applying the filler. Another method is to remove the top layer of finishing plaster (3-5mm deep) around 20mm or so either side of the crack, apply plasterers fibreglass reinforcing tape over the crack & then fill/blend to the surrounding wall area. If they still reappear, there is almost certainly some differential movement in the wall underneath, this is usually due to cracks in the blocks or in the mortar lines between them. It’s rarely a problem structurally but major remedial work involving hacking off plaster, render & steel lath reinforcement is involved or you will never get rid of them; unless you’re doing major renovation works anyway, it’s easier to accept & live with them.