retentions

just wondering what peoples thoughts are on builders holding back retentions on new builds or extentions etc or the builder expecting you to go back and put the work right for free after a few months
personally i think it is wrong,as most of the work that has to be done is down to shrinkage and is not the decorators fault in any way , especially when the job you did had no central heating on until the last few days before finishing

been asked a couple of times to sort out shrinkage etc and...

retentions