hairline cracks appear when it gets hot....!

[Paulboy]

When we have a hot day one part of the house gets warm and some hairline cracks appear, nothing more than that but quite obvious. When it cools down hard to see cracks. We had house completely replastered a few years ago. It us now decorting time and I wondering the best way to fill these.

What's the best product to use.?maybe flexible chaulk filler. Should I also do it on a hot day when the crack us at its biggest? Then sand off ant that's squeezed out..?

 

[Paulboy]

Any one?

 

[misterhelpful]

Cracking is common for the first couple of years after plastering and is usually just down to settlement but problem with hairline cracks is getting the filler into them. It may be necessary to widen them slightly with a stanley blade before filling but I have found that one of the lightweight ready-mixed fillers can sometimes be pressed in quite well without the need for this. As you suggest, it's best to fill while the cracks are at their widest but excessive movement will probably lead to more cracking in the future.
Don't use caulk as it is not sandable, has a completely different texture to plaster and will stick out like a sore thumb in the middle of a wall - it is only really suitable for filling cracks/gaps along skirtings, architrave windows etc.

 

[NickB_99]

What's the best product to use.?maybe flexible chaulk filler. Should I also do it on a hot day when the crack us at its biggest? Then sand off ant that's squeezed out..?

Agree with misterhelpful - decorators caulk is not sandable.

Maybe you could apply some and wet it after to smooth away excess, but applicator is really geared up for in corners (skirts, architraves etc). It is flexible which may meet your requirement.

A better option for flat surfaces is usually easifill, which can be sanded flat after.
I would perhaps get some and give this a try. If you mix it quite thin, it will perhaps get into the cracks more readily.
The bit I'm not sure of for you is I don't think it's particularly flexible, and if cracks close up and re-open, whether it will reoccur.
Have a go on a few of them and see how it goes

 

[Paulboy]

Thanks guys will try easifill

 

[stevethespreader]

Thanks guys will try easifill

are these cracks on joints or seams paul?

 

[Paulboy]

The cracks arent on neither. The whole house was reskimmed. Some was d+d. This part was just skimmed. Problem on occurs when it gets hot

 

[stevethespreader]

The cracks arent on neither. The whole house was reskimmed. Some was d+d. This part was just skimmed. Problem on occurs when it gets hot

so there just random cracks and not on joints in straight lines? then do as above just widen them and fill with easifill