laying a laminate floor

[steve_moran38]

putting down an 8mm laminate floor in a through living room. There's a difference in height half way along the living room floor by about 5mm. I'm laying on top of an existing wooden floor. Any suggestions as to the best way to take up the gap? I have a thin moisture resistant underlay to put underneath the laminate but it's only about 2mm

 

[big-all]

5mm is minimal

work back 1m thats the point the flooring should start to rise take some hardboard lay from the step to the 400mm point from the lip and secure to the floor
take 2x 600 bit off underlay and fold 250 onto 350 and secure to the hardboard one on top and one infront this will support the floor in addition to the normal underlay

ok re read and its a dip same applies except its seperate layers with 1x2mm required where 0.3-0.5 thicknes is required and 2x2mm required where 0.7 to 1.25mm are required to help the transition between solid surfaces including mdf or hardboard packers

 

[WoodYouLike]

I have a thin moisture resistant underlay to put underneath the laminate but it's only about 2mm

DPM on existing floorboards? Don't use that, it will restrict the natural needed ventilation and could cause moist problems on your floorboards and even joists in the long run.

Get a foam underlayment of 3mm without a DPM or moist resistant layer and follow big-all's advice on how to tackle the dip.