odd crack

[Paulboy]

I have had my house completely renovated, replastered throughout and we are very happy. The is however one odd spot in the house. when we had some really warm days(shock i know , we've had one or two!) the outside wall on a small area gets a lot of sun and so gets warm. When this happs a very thin hairline crack appears about 60 cm long. It then cools down in the evening and the crack then dispears. i know things contract and expand with warmth moisture. This seems a bit wierd though.! Any ideas?

 

[Fluffster]

Sounds exactly as you say normal expansion and contracting of different materials at different rates.
Fill it with a flexible filler or eggshell paint to disguise.
Pete

 

[Paulboy]

yea i filled it once with paint , but it obviously filled bk up and the paint was squeezed out, so i had this line of paint which ive now sanded down.