Floating Floor (Insulation & T&G Chipboard) - Sand v

[EViS]

I will be installing a new floating floor in my garage conversion and looking for some advice on how to go about this.

The existing garage floor is approximately 140mm lower than the remainder of the house. The garage floor is fairly level (i.e. not sloped towards the garage door) but does have a few dips, primarily around the perimeter.

I will be installing a DPM, 100mm PIR (Celotex) and 22mm T&G Chipboards. However, how should I make up the additional 18mm of height?

Should I flatten the existing floor with an 18mm bed of dry sharp sand (or kiln dried sand)? Or should I pour some self levelling compound down?

And where should the DPM be inserted?

 

[theoldun]

We are trying to decide on our floor structure within our garage conversion. The existing floor is concrete, lower than the rest of the house and sloped. The highest point of the floor is 200mm lower than the rest of the house.

The above was your post Sunday just gone.
To-day your floor has risen by 40mm and leveled its-self out.
Tis making me scratch me ar8se, if nothing else.
Regards oldun

 

[EViS]

I was waiting for someone to quote that . Only today did we create the knock-through and took an accurate measurement between the two spaces. Hence, not enough space for screed as we previously thought (and mis-measured the height difference). Having now drawn a line around the entire perimeter, we can see there is a slope in deed, but considerably less that we previously guesstimated, so much so that you may as well call it 'flat'.

Apologies for the confusion.

 

[EViS]

Any chance anyone could answer my few questions please ?