Insulating 6x5m Tin Garage with Polystyrene: Best Practices, Sealant for Concrete Connections

Hello. Recently I started building a garage measuring 6x5m. Garage is almost ready. Until the winter, I plan to insulate it from the inside with polystyrene and this is where the stairs begin, because I want to do it in the right way. Garage made of 60x60x3 profiles, (load-bearing pillars), the rest of 40x40x2. The height at the top is 3.3 m, the slope is 10%. Roof made of sandwich panel with 40mm polyurethane foam. Walls made of T-18 0.6mm trapezoidal sheet. You might ask why not a sandwich panel? Well, of course, it's about the cash ... The cost of a square meter of a 40mm board is about PLN 60 net. Besides, there would be a lot of waste, for which of course you have to pay. I, as an ordinary young Pole, do not sleep on money and have to combine. I thought to myself that I would calmly warm up to winter with 40mm styrofoam, but just how to do it so that it does not condense? Another problem is how to seal the garage from below? (concrete-plate end connection). I count on your advice! Greetings.
PS: Photos for a better picture:

I suggest mineral wool, there is no problem of condensation.
Don't let anyone tell you that there are styrofoam vapor-permeable polystyrene, they just soak up.
A simple test, put a piece of polystyrene in the water and see after a few days, it will be wet like a sponge.

hmm, I heard that it also condenses and what is more, wool absorbs moisture and rots with time. Tell me, the profile is 40mm and this is the thickness that I have to use for insulation? In the case of wool, can I give 50mm and squeeze into a trapezoid in these places? Any insulating foils will be necessary?

The first thing is foil because wool or polystyrene will rot.

So, counting from the outside - trapezoidal sheet -> foil (permeable or insulating?) -> mineral wool (40 or 50mm?) -> thin sheet? Will such a scheme be correct? I want it to last at least 20 years .

The field is not completely honest, because there are buildings all around (a farm). When writing the distance from the plates, what do you mean? How to do it?

If the floor is not insulated, it is not a pity to work on 4 cm of insulation with polystyrene? Why are you warming, will you work there in winter?

And the trapezoid cannot fulfill an air gap? After all, it's about 18mm. Unfortunately, I am limited by the total thickness of the wall and I have to deal with the insulation in 40mm to elegantly close it in the profile. As for sticking polystyrene, I think that in my case it is unnecessary because I have 40 mm profile reinforcements in 3-4 places along the entire length of the garage and you can push the styrofoam into a squeeze.
edit: The spout is not insulated, but is 25 cm thick. Exactly so, in winter, when there are long evenings, I want to tinker there and construct various trifles . Recently, winters are not too harsh, but always. If I have to bury something there, I would like to be able to light up in a goat-type stove with chamotte bricks, so that after 2-3 hours the temperature would be acceptable, i.e. above 10-15 * C and that the heat would not escape too quickly.

in winter in the evening, he will not use the window much, it is enough to have a ventilation grille plus forced exhaustion if he is soldering, welding, painting, etc.

The window is nice and necessary, in winter you can cover the most with polystyrene.

Now I have a headache. 2cm polystyrene is probably a little bit? The couch is off, because it is also a garage for a car and I would just have too little space. And the project that I will be creating in the near future (buggy barracuda) will take up a lot of space. I repeat the question, can the trapezoid not act as a ventilation?

You have uninsulated concrete as a floor, and whether 2 or 4 cm of polystyrene is actually no difference. You're gonna be cold. Perhaps at the beginning, do not punch it with anything from the inside in a permanent way, just so that you can disassemble it, so that you can modify this insulation after the first winter.
As colleagues wrote, think about a window, maybe a skylight in the roof. It does not have to be big, and it will provide a lot (!) Of light during the day.

I see. However, it seems to me that an uninsulated floor will not have a major impact on heating the interior. Warmer air is lighter and rises to the top. The roof is made of tiling with PUR foam, so a significant part of the heat will not escape. Another advantage is that it will not condense, as is the case with an ordinary sheet. When I insulate the walls and seal all the nooks and crannies, I think that when I light up in an ordinary fire-clay stove, I will be able to heat something up there, for sure a lot of heat will escape less. This is not an apartment but an ordinary garage. Just when there is a need to do / repair something in winter, I want to be able to light it in the stove and after 2 / 3h the temperature will be bearable. However, I want to do it correctly to have peace of mind for a few years.

As far as I can see in the pictures, the window is already there.
Secondly, do not do anything temporarily because then it will stay this way and there will be no time / willingness to make corrections.
Third, calmly do the polystyrene as planned and it will definitely be better than no insulation. However, you need to stick the polystyrene, because the wind will scrape its own after some time, the syrup will oxidize and everything will fall down.
Fourth, you need to insulate the floor, or at least insulate it. The easiest way is to throw the old gumolite and a lattice of boards on it.
Fifth, what horror no one wrote !!! If you want to warm up with a goat, first of all, a good treatment around the chimney, not any makeshift and MUST ventilation grille, no window. The carbon monoxide sensor will not hurt either, because in such a small space it is enough to blow into the chimney, take back the exhaust gases and sweep it away.

This is what I created this topic for, to avoid mistakes and do it once in a good way and have peace of mind for years. I have no experience, so I prefer to ask you professionals .
When it comes to polystyrene, it cannot fall off, because a thin sheet of metal will be riveted / screwed in from the inside, creating a kind of wall. But that's right, glue is terribly expensive, so it won't hurt to stick it.
What if I used 3 cm styrofoam and bought a 1 cm package and made an air space between the trapezoidal sheet and 3 cm polystyrene to a thickness of 1 cm? Will I need any more foil? If so, what and where.

My friend cannot touch the sheet metal because the sheet will be wet in winter and everything will be wet from it.
I'll tell you that fucking .... you could have given a sheet of polystyrene, siatex and glue on the outside and it would be over.

I also recommend the author of the topic to read the topics that were in this section:
Warming a tinplate - your advice
Tin garage "tinplate" seal.
Leaking water in a tin garage.

You can and yes, but I don't want to insulate from the outside. So without any foil, I buy 30mm and 10mm styrofoam, stick small 10mm squares on the corners of the 30mm board and stick the whole thing from the inside. Small gaps with low-expansion foam and a thin sheet for rivets. I bought an insulated door, the door will be made of a 40mm sandwich panel with PUR foam (I already have the material) and should it be guitars? I am also asking for advice on how to seal the sheet at the contact with concrete so that no water flows inside.
@ANUBIS, thanks for the links. Before I started the topic, I read a lot, but I had some doubts about it, hence the topic.

In my humble opinion, it must be carefully insulated from the inside with a vapor barrier. That is, sheet metal, thermal insulation, foil and, for example, rigips.
When warm, humid air gets from the inside to the sheet metal, it will then dew dew. Air gaps practically do not improve thermal insulation.

I know that air gaps do not affect thermal insulation, it is more about protecting the sheet against condensation, as I understand correctly?

If there is no water in the air, it will not condense, and there is much more water in warm air than in cold air. Only very good insulation from the inside, which is impermeable to water vapor, will prevent condensation.
There are descriptions of, for example, insulation of a house from the inside in the network, and the most important thing there is protection from steam from inside the house.

As far as I know, there is always water in the air and the water will condense on the plate due to the temperature difference, so probably a colleague wrote above about the air gap - if I understand correctly.

Colleagues in the spring and autumn are literally pouring from the sheet metal, such amounts of water condense the sheet metal.

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And when you are going to make racks on the walls, e.g. from a GK profile, then it is vertical.

Which side of the plate is the water pouring on?
I know from my own experience that when it warms up and protects against air from inside, not a single drop will appear on the inside of the sheet.

It is pouring inside the floor, as shown in the photo, the sheet does not stick tightly to the concrete. I have to seal it with something.

Today I bought something like that in casto ..... "construction sealant" by soudal for PLN 12 a 300ml tube. I hope it will pass the exam. I also bought a 20mm styro for a trial. What is the best cut and glued?