Laminate flooring - uneaven floor

[macka001]

Hi i am looking to replace the carpet in my dining room/extension.
Ive lifted the carpet and noticed that the dining room, is standard timber floor, but where it joins the extension, the floor drops into the extension. i used a spirit level to measure the drop, which is 26mm from dining room, to extension. the previous owner/builder has used levelling compound to made the drop a gradient.

now im thinking of laying laminate flooring, and as its a through diner to extension, i wanted the laminate to run all the way through, however with this drop in the floor level within the extension, how can i pack it?

The other complication, is that the UPVC door leading into garden, is currently 40mm above the floor level in the extension. im looking at 7mm laminate with 3mm underlay, again any ideas.

Thanks

[stoneyboy]

macka001,
"how can i pack it" - you have two choices, either lay a 26mm thick floor ontop of the exisiting in the extension or have a step between the two rooms.
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[macka001]

ok, but i havent seen 26mm ply or chipboard. i was thinking of laying some 3mm foiled underlay down first, then some 22mm chipboard screwed down into the tiles, and then another layer of 3mm underlay on top. any thoughts?

[chris_on_tour2002]

how about doing what the original builder did and use self levelling?

[stoneyboy]

macka001,
25mm ply is available from timber merchants or build up layers 10+10+6.
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