Converting garage to bedroom - uninsulated slab => Click flooring: what in between??

[Arresthlm]

Hello!

Our house, which is a Boro house from 1989, is built on concrete plinths (crawl space) and directly adjoining it is the garage, which stands on an uninsulated slab.

Now I'm planning to convert the garage into living space for two bedrooms and I'm wondering how to approach this project from a "floor perspective": I was thinking about both heat (losses) and also problems with moisture, etc.

The house is heated with an air-borne heating system (Bahco) with FTX, which I plan to extend out to the extension, but will supplement with electric radiators.

Regarding the floor in the garage, it is an uninsulated (I think) cast concrete slab, with a height difference of about 20-30 cm. I have tried to read up on various threads in this forum but also on other forums, and this is what I had planned to attempt. Do you think it will work??

- Uninsulated Concrete
- (Aging-resistant plastic?)
- Platon mat
- Rigid foam insulation
- Floor chipboards
- Underlay foam
- Click flooring
- (ventilated moldings???)

 

[Arresthlm]

No one?? This forum is usually an endless source of accumulated knowledge for such projects...

 

[ullet]

I did something similar in our garage, it's worked fine but is a bit colder than the rest of the house, maybe I needed thicker insulation...

1. Platonmat
2. Cellplast insulation (I think 3.5 cm, didn't want a higher floor than that)
4. Step damping foam to avoid creaking
3. Oak parquet
4. Ventilated moldings

 

[Arresthlm]

I did something similar in our garage, it has worked okay but is a bit colder than the rest of the house, maybe should have had slightly thicker insulation...

1. Platon mat
2. Foam insulation (I think 3.5 cm, didn't want a higher floor than that)
4. Step-damping foam to avoid creaking
3. Oak parquet
4. Ventilated moldings

Thanks Ullet!
So you went with the floor directly on the foam without chipboard in between - was it because you didn't want to raise the floor more?
And then there's the matter of age-resistant plastic between the foam insulation and the concrete - maybe it's just unnecessary since the Platon mat is non-organic and maybe serves the same function?

 

[ullet]

Yes, I laid the floor directly on it, didn't want to raise the floor more but fundamentally think it shouldn't be necessary if you choose a slightly thicker floor (14 mm parquet in my case, plank floor would have been even better) and correctly classified cellplast, if you're going to have laminate or some other thinner floor, it's probably good with the chipboard.

I don't think you need the plastic, the Platon mat is age-resistant and diffusion-tight, should also result in better "ventilation" if you skip the plastic.

By the way, I folded the Platon mat up against the walls so there would be free airways up to the ventilated strip, so to speak.