Heated room in siporex storage.

[stoffe88]

I have planned to build a room (10m2) in the storage area that can maintain a few degrees above freezing during winter. Currently, it is built from Siporex in large blocks and a roof of asbestos cement without any insulation.

What I need help with is how to go about the air gap, insulation, plastic, etc. The walls are, as mentioned, made of Siporex, approximately 150mm.

I'm looking for a construction that can manage without heat from the inside in the future. I searched the forum and became a bit uncertain about the pros and cons of plastic, for example, in the summer when it's warmer outside than inside.

Anyway, I'm considering doing the following:

1. Outer wall in Siporex.
2. 45mm stud (as an air gap)
3. Wind barrier.
4. 70mm stud & Insulation.
5. Durable plastic.
6. Chipboard / Plasterboard

Is this a correct way to build?
I apologize for any typos that might be present; it's hard to sleep when you have important thoughts on your mind :blushing:

 

[Blindnit]

There are probably as many opinions as there are members
I'll start
Without knowing how it works over time, I should add.
I see that you want 70mm insulation or alternatively expand 115mm with insulation/air gap.
An option that should work in a cold storage is to fasten OSB/plywood through 70 or 100mm cell plastic with reasonably long screws.
Drilling and plugging beforehand and then finding the screw holes is a bit of a sport, but it works

 

[MathiasS]

Siporex is a good wall material, so I wouldn't say your storage is particularly uninsulated. My house is partially built with large Siporex elements, and during renovation I inquired a bit: Plastic in the wall was not recommended. Insulation was primarily suggested to be mounted on the outside. If you want plaster on the inside, it can be glued directly onto the Siporex.

Walls that are not part of the outer walls I would probably build without plastic since you want to be able to run without heat.

 

[stoffe88]

There are probably as many opinions as there are members
I'll start
Without knowing how it works over time, I should add.
I see that you want 70mm insulation or alternatively build out 115mm with insulation/air gap.
An option that should work in a cold storage is to fasten OSB/plywood through 70 or 100mm polystyrene with decently long screws.
Drilling and plugging before and then finding the screw holes is a bit sporty but it works

Thoughts about polystyrene directly against siporex I've had but how do you do with the remaining part of the interior wall step by step? Here you probably don't need Å-B Plastic inside? If you want to be able to attach OSB boards without searching for plug holes, just frame and place the polystyrene in between just like you do with regular insulation?

Siporex is a good wall material, so I wouldn't specifically say that your storage is uninsulated. My house is partly built of large siporex elements and during renovation of this, I inquired a bit: Plastic in the wall was not recommended. Insulation was suggested to be mounted primarily on the outside. If you want gypsum on the inside, it can be glued directly to the siporex.

Walls that are not part of the outer walls I would probably build without plastic since you want to be able to run without heating.

I am aware that Siporex insulates well I meant additional insulation but you understood that! Unfortunately, there is no possibility to insulate from the outside as the room itself will only cover 1/4 of the total building and is located in the middle of it.

If I understood you correctly, you can plastic but only on the outer walls? and ceiling?

 

[Blindnit]

I was thinking of just putting cellplast against the wall without studs, then screwing through it with OSB/plywood.
I thought I wrote that?
That way, you avoid putting studs against the wall and the problems that can entail.
A lot of today's "construction problems" are probably due to crappy materials.

I am "renovating" myself and am throwing away, among other things, 60-year-old heartwood to replace it with "new fresh straight" as well as glued sawdust instead of real wood.
Generations after us will call us "the big idiots."

 

[stoffe88]

Then you don't have to attach battens to the wall and avoid the problems that can entail. Also, a lot of today's "construction problems" are likely due to poor materials.

What problems are you referring to?

If I were to choose Styrofoam for the walls, what should I do with the ceiling? As it is now, there’s only asbestos cement, and it’s not 100% tight.

My idea for the ceiling is to apply a layer of plastic under the sloped "ceiling joists" so that any moisture that gets through the ceiling runs down into the air gap. But if I choose to glue Styrofoam, there won't be an air gap...

 

[MathiasS]

I mean that you should not use any plastic in connection with the siporex wall.