Cracks in plaster

Leif

Meadows wrote: »

if you just paint over them you will see the cracks.

No you won't, not if they are hairline cracks. Wider ones, yes, do as many suggest. EasyFill is a very good powder filler, widely used by builders and plasterers. I tried Unibond ready mixed filler, it's dreadful stuff.

Meadows

Meadows wrote: »

As tco03 says. slightly open them up with a scraper and then filler & sand smooth, if you just paint over them you will see the cracks.

Leif wrote: »

No you won't, not if they are hairline cracks. Wider ones, yes

Really, so after we had a wall plastered (dried slowly, no heating) we had hairline cracks, why did they show through after being painted with several coats of paint?

Buellguy

Leif wrote: »

No you won't, not if they are hairline cracks. Wider ones, yes, do as many suggest. EasyFill is a very good powder filler, widely used by builders and plasterers. I tried Unibond ready mixed filler, it's dreadful stuff.

+1 for Easi-fill - you can get it from B&Q etc - just get the stuff with no number on it. The number after the name gives the WORKING time in minutes (i.e. if it's Easi-fill 20 you only get 20 mins to get it in the cracks). The stuff was recommended to me on my plastering course

keystone

Meadows wrote: »

Really, so after we had a wall plastered (dried slowly, no heating) we had hairline cracks, why did they show through after being painted with several coats of paint?

Perhaps because it was thin as ....... stuff from the sheds or you thinned it too much? A high build paint would have covered them up. Expensive basecoat stuff - waste of money unless the wall is bad and very fine hairline cracks don't count. Its also a total waste of time to rake them out too - the decent paint will cover them easily.

Cheers

keystone

Buellguy wrote: »

.....you only get 20 mins to get it in the cracks.........

A short pot life is actually a pretty good incentive to get on with the job and not faff. In any event how long does it take to fill a few cracks?

Cheers

Leif

Meadows wrote: »

Really, so after we had a wall plastered (dried slowly, no heating) we had hairline cracks, why did they show through after being painted with several coats of paint?

Either what Keystone said, or they were not hairline cracks. I had quite a few fine cracks in two kitchen walls. A touch up with a paintbrush dipped in Dulux matt emulsion, and a quick roll with a mini roller, and they've gone. I also do this with ceilings. I think emulsion is more elastic than some fillers, assuming fine cracks of course. It does annoy me when cracks appear, but it's not the plasterers fault, just reality intruding.

Buellguy

keystone wrote: »

A short pot life is actually a pretty good incentive to get on with the job and not faff. In any event how long does it take to fill a few cracks?

Cheers

Depends on how many cracks there are and how big the wall is . I've been using the no number stuff (45 mins working time) and I have found that after about 30 mins it's not as easy to work in (bear in mind the stuff is actually designed for filling the joints between sheets of plasterboard)

Meadows

keystone wrote: »

Perhaps because it was thin as ....... stuff from the sheds or you thinned it too much? A high build paint would have covered them up. Expensive basecoat stuff - waste of money unless the wall is bad and very fine hairline cracks don't count. Its also a total waste of time to rake them out too - the decent paint will cover them easily.Cheers

New, quality paint, two coats, not watered. So no a decent paint does not cover cracks!

keystone

Your definition of hairline and mine are obviously seriously at odds then. Thats OK. However, it makes your second sentence a subjective opinion rather than the definitive fact it seems to be trying to be presented as.

Cheers

Meadows

I no longer have hair line cracks (and not have had for many years since we did as mentioned in a previous post), and the second part of my sentence was definitive as a decent paint was used, this was mentioned as you were suggesting old or thinned down paint from the back of a shed or a less than quality paint had perhaps been used ☺