Best approach to building a subfloor on top of a concrete base in garage conversion Help, advice, information, answers and tips on all types of flooring from laminate and carpet to timber and vinyl

[Urf]

Hello

First timer here. I am not a builder, just someone trying to do as much as I can diy-wise as I have limited budget.

I am in the middle of converting my detached, double-skin (no cavity) garage into an office/cave. It currently has a concrete floor (5.5m x 3.3m) and I'm not sure of the best way to build and insulate my subfloor. I've searched around a bit and cannot find any information on how best to tackle this. One friend, who is more experienced at diy than me, suggested the following layers:

- DPM on concrete floor
- Treated batons
- Treated 3x2 joists at right angles to above, with Celotex/kingspan in between
- Chipboard or OSB
- Final finish, possible some kind of vinyl or linoleum, ie something that can take a bit of bashing but is easy to clean. Other budget-friendly suggestions welcome!

Does the above seem ok?
Would there be adequate ventilation, if any? Or is this not an issue?
Is there a better alternative?

Thanks for any help or advice.
Urf

[diydoctor]

Lay 75mm cellotex directly onto DPM. Leave no voids. Lay Tongue and grooved chipboard on top of Cellotex glueing joints as you go. Then coat the chipboard with 3 coats of SBR diluted 50/50 with water. Let it dry and you can la any type of floor finish you like except tiles