Raising carpet height (insulation board)

[ClockPie]

Hi

Need to decorate/re-carpet living room. Not sure what thickness the carpet/underlay is but was thick, but the carpet is *roughly* 25mm lower than the hallway (engineered oak). This "lip" is annoying me and stopping me getting a robot vacuum! So I have to use a manual dyson - how 1990s!

From memory, base floor is wood/raised but not 100%. IIRC it was draughty (1930s).

Was thinking I could just fix ply or something before grippers and underlay/carpet, but is there a type of insulation board that could be used? I've used boards for under solid surfaces successfully, but not carpet? Obviously need to be compressable and impact resistant. Seen some but only 3-4mm thick but ideally 10mm ish would be great - get some insulation AND raise the floor.

Early days, not even ripped up corner of existing carpet to see the facts, so just seeing ideas for now.

Thanks

 

[dazlight]

Would a slope work. You could use stairrods shims.

 

[robinbanks]

Tile backer boards with a layer of 6mm ply glued on top, joints offset?

 

[ClockPie]

A small slope may work, but would need to buy a robot and see what its approach/decent angles are first - but may not be ideal.

Tile backerboards (or xps) have been considered, though is 6mm ply flat enough or strong enough? Mentally if feels a little unsubstantial for heavy loading and may "feel" naff.

 

[robinbanks]

I recommended you glue it down; it becomes part of the existing floor which is demonstrably strong enough already. All the thinner layers are doing is transferring load to the existing floor

 

[foxhole]

6mm hardboard is used widely under carpets to hide board joints .

 

[simplesteve]

Easiest, cheapest and simplest solution is a wide and sloped bespoke door threshold bar. Easy enough to knock up.
12mm ply is best if you’re bringing the floor up, but it’s not cheap !