Hello,
I paid a bulider just six months ago to lay a laminate floor in my lounge , six months later it has begun to rise in various places , I am very upset about this , and he's not prepared to put it right , so it looks as though I must try and fix it myself , trouble is I don't know why its happening . He use a liner and seemed to take his time but several of the strips are rising and when you walk across them a definite dip , any answer,s anyone... judy from Cardiff

I would have to say make him set it right or take him to court. Could be some well placed hints of retribution may get him back to fix it.

Probably didn't leave an expansion gap around the perimeter of the floor, not doing this would make the floor bubble or dip in places. Laminate needs to be able to expand and contract with humidity.
Did he allow the laminate to acclimate for at least 72hours in the room to be installed prior to installing??

In most states the contractor is responsible for his or his worker's workmanship for a period of one year. Within that time he must make the repairs. If, and I do not think it is, it is a material defect, then the manufacturer would warranty the materials only and not the labor. Sounds like you got a bad job. Call him up and let him know if something is not done in 10 business days you will be taking further action to the fullest extent of the law.

Here's The Problem, You Must Have Some Cased Openings Or Some Door Jambs In The Room Or Around It, A lot Of Times The Casing And Jamb Don't Get Cut Out Correctly, Either They Don't Know There Supossed To Or They Just Don't Have The Tools To Do It, Never The Less These Floors Will Move, And You Need A 1/4 Play Around The Floor,
What You Can Do Is Buy You A Dove Tail Saw Or A Jam Saw, Its Just A Flat Saw You Can Lay On The Floor, (lay Something Between The Saw And Floor To Prevent Scratchs, But You'll Need To Undercut Where You Have Doors And Casing Touching The Floor, Check To See If There Is Any Caulk Around Any Joints, Because There Shouldn't Be, Next You Can Try A Dehumidifier To See If There Is A Moisture Problem, But You Should Be Fine There Being You Said Hes Installed A Liner,

So To Sum It Up, You Floor Is To Tight Somewhere, Find It, Fix It, Your Done