Subfloor height difference


Old 04-03-18, 01:03 AM
Thread Starter
Join Date: Apr 2018
Posts: 2
Received 0 Votes on 0 Posts
Subfloor height difference

Hi everyone,

Iím installing a new 22mm tongue and groove subfloor for an engineered wood floor. The room was previously two rooms that have been knocked together, and there is a height difference of around 22mm between the two. The first layer of subfloor is down and I plan to sheet over the lower of the two to create an underlayment to bring it up to level, and would appreciate advice on suitable materials: my current thoughts are some 8x4 sheets of 18mm OSB3 and then a layer of 4mm ply or hardboard, but would like to hear what other people think. Given that this is in a kitchen would some sort of membrane on top of the underlayment be a good idea to protect against spills, or would a good quality underlay handle this?

Many thanks,

Sponsored Links
Old 04-03-18, 06:00 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,555
Received 315 Votes on 289 Posts
Why not use the same 22mm thick material throughout instead of trying to make up the thickness with two sheets of other materials?

I would not install a waterproof membrane. Your floor isn't going to be waterproof so I don't see any benefit. If there is a water leak the membrane will trap the water and cause it to spread.
Old 04-03-18, 07:01 AM
Thread Starter
Join Date: Apr 2018
Posts: 2
Received 0 Votes on 0 Posts
Thanks that sounds a much better suggestion: Iím not sure why Iíd not considered just using 22mm sheet originally.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: