Build a sauna wall that is moisture-proof against the floor, how should I think?

[nizzehult]

Agree with the latter. And the insurance companies probably do too. Regarding your idea, I think the ventilation will be too good if there is a gap there. And then you cool down the sauna. Air should only come in just below the heater, not in other places.

 

[Matti_75]

Agree with the latter. And the insurance companies probably do too. Regarding your idea, I think the ventilation will be too good if there's a gap there. And then you'll cool down the sauna. Air should only come in just below the heater, not in other places.

And there you are wrong. You can never have too much air in a sauna. I have built outdoor saunas with only a decking floor and haven't had any problems with that.

 

[Jonatan79]

Agree on the latter. And the insurance companies probably do too.
Regarding your idea, I think the ventilation will become too good if there's a gap there. And then you'll cool down the sauna. Air should only come in just below the heater, not in other places.

How can you cool down a sauna if the air comes from a heated room next door? It's also not important to bring in air right next to the heater if it's not wood-burning!

 

[Anna_H]

Oh, but try playing that card with the insurance company if you happen to have water damage!
- Why does the wet room lack a moisture barrier around the sauna?
- Eh, it's unnecessary because it dries so quickly anyway.
Note that this is a wet room, and in such a room must - not should - there be a moisture barrier on all walls and on the floor.
The alternative for me would have been to put a moisture barrier on the studs and then build the sauna on these; the only difference is that the moisture barrier in this case consists of the plastic.

I was a bit taken aback when I realized that you are the OP.
Since your plan is to be able to remove the sauna, you should build the bathroom first with moisture barriers everywhere. Then you install a sauna inside that space. I assume you do not intend to have a washbasin and toilet in the same space but have another bathroom/WC?

Or am I misunderstanding, so that the sauna itself is the area you have specified, and it is a bathroom too? Regardless, you must have a moisture barrier in the whole room first, since you want the same flooring throughout. Otherwise, you won't get approved moisture barriers in the bathroom, considering that the wall towards the sauna according to your plan won't have a moisture barrier.

 

[nizzehult]

I was a bit surprised when I realized it is you who is the thread starter. Since your plan is to be able to remove the sauna, you should first build the bathroom with a waterproof layer everywhere. Then install a sauna within that space. I assume you don't intend to have a washbasin and toilet in the same space but have another bathroom/WC elsewhere?

Or am I misunderstanding, so that it's the sauna itself that's the area you specified, and it's also a bathroom? Regardless, you must have a waterproof layer throughout the room first, since you want the same flooring all the way. Otherwise, you won't get an approved waterproof layer in the bathroom, considering that the wall against the sauna, according to your plan, won't have a waterproof layer.

Yes, I will also have a WC and washbasin there, but I also have another bathroom two doors away.

Sure, I understand that if in the future I have to remove the sauna completely, the walls that will now become the sauna's side and back walls (consisting of existing walls in the house) would also need to have a waterproof layer similar to the part that today is not going to be a sauna, like Kiilto.

If I had an extra half meter to work with, I could have built the entire bathroom with a conventional waterproof layer and tiles on all walls at once and then built a freestanding sauna inside it. But now I don't, so the sauna will be somewhat integrated into the bathroom. I will lay the floor first, and Kiilto's waterproof layer will cover the entire area, folded up against the walls.

Foil on the walls of the sauna constitutes the waterproof layer. It was the same in my previous house and it should be approved.

It was also not ventilation I was asking about in this thread, so I wonder why I'm getting more or less qualified posts from others about that? I have that part quite clear.

 

[Harpgear]

A bit strange to consider insurance companies and their requirements while explaining how to build completely against regulations. Not judging, as I've built totally against regulation bathrooms myself, but I'm not dreaming of any compensation when moisture one day has eaten into the wall.

 

[nizzehult]

A bit strange to consider insurance companies and their requirements while explaining building completely non-compliant. No judgment since I have also built entirely non-compliant bathrooms, but I don't dream of any compensation when the moisture one fine day has eaten its way into the wall.

Can you elaborate on this with non-compliant? I think of it as two separate "rooms" sharing a floor and having different solutions for the waterproofing. Built like this before and it was considered OK and didn't cause any remarks when the house was inspected last year before the sale.

This is what it says in GVK 2021:

In moisture zone 1, waterproofing should consist of plastic sheeting, waterproofing membrane, or boards with waterproofing.
Bathroom and shower spaces should be provided with a waterproofing membrane on floors and walls.
Toilet rooms, laundry rooms, and spaces for water heaters should have a waterproofing membrane on the floor with an upturn on the wall.

I equate this room with a toilet room, not a bathroom or shower space as the only running water available is what's going to the sink and the toilet.
Moisture zone 1 is the floor, nothing else, and conventional waterproofing will be laid there with an upturn.

The sauna is considered a different space that is actually separated from the rest of the area, and I welcome any opinions on this.

 

[Harpgear]

You cannot build a floor for two rooms and mix waterproofing layers; if you make two rooms with even floors, with unbroken waterproofing layers according to established standards, then you’re good. Personally, I would do as you mentioned, but with the entire room as a wet room and partition off with a screen wall loosely standing on the floor.

 

[Harpgear]

Yes, if there's only a toilet then maybe there's a possibility, I don't have any knowledge about the rules regarding the sauna area itself.

 

[Anna_H]

Sauna without a shower then?

 

[nizzehult]

Sauna without a shower then?

Yes, unfortunately. A shower simply doesn't fit, but it's two doors away, so that's the compromise one has to live with.

 

[nizzehult]

I am facing a somewhat similar project, with a minimal sauna in a combined laundry room/bath/shower in the basement.
For the freestanding walls, I plan to lay a loose wooden stud equipped with two strong rubber strips underneath, against the existing tiled floor. There will be a tiled baseboard on both the inside and outside.

OK, yes that could probably work but how tall were you thinking of making it then? It feels like it should be at least a few cm and then maybe a composite stud would serve the same function? Another problem could be that the rubber might stain the tiles, and it could be a pain to remove if it needs to be gone at some point in the future.

After checking prices and starting to familiarize myself with different glass fittings, I have concluded that this should be the cheapest solution, but it may not be as narrow or elegant as a custom-made 8mm glass wall:
A frame of 45x45 structural timber is built on both sides where the door will sit. The part resting on the floor is made of composite.
The frame is nailed to the wall and ceiling and glued with silicone to the floor.
A regular glass sauna door with a frame (possibly with an aluminum frame) is placed between the frames.
A narrow strip about 15mm that functions as a rebate is nailed to the inner part of the entire frame, alternatively, this can be routed out before the studs are made.
Two custom-made 8mm tempered glass panels are placed against this strip, and a quarter mold about 20mm that runs around the windows on the front side is screwed in and functions as a lock to hold them in place. It doesn't need to have beveled edges on the glass; sanded down edges are sufficient (35% cheaper). Possibly a rubber strip on the inner side is needed to channel away water when the steam hits the glass.

This entire solution costs somewhere between 4,000-5,000,-.
The difficulty, however, is finding a door where the frame is only 45mm deep; so far, I've only found 70mm...

 

[GoForIt]

OK, yes, that could probably work but how high were you thinking of making it in that case? It feels like it should be at least a few cm and then maybe a composite batten serves the same function? Another issue could be that the rubber may discolor the tiles and it could be nearly impossible to remove if it has to be taken away in the future.

After checking prices and starting to understand different glass fastenings, I have concluded that this should be the cheapest solution, but it might not be as narrow or elegant as a custom-made 8mm glass wall:
A frame of stud timber 45x45 is built on both sides where the door is to be placed. The part resting on the floor is made of composite.
The frame is nailed to the wall and ceiling and glued with silicone to the floor.
A regular sauna glass door with a frame (possibly with an aluminum frame) is installed between the frames.
A thin strip about 15mm that acts as a rebate is nailed to the inner part of the entire frame, alternatively, you could rout this before the battens are made.
Two custom-made 8mm toughened glass panels are placed against this strip and a quarter-round strip of 20mm running around the windows on the front is screwed in place and acts as a lock, holding them in place. The glass doesn't need polished edges, reduced edges are enough (35% cheaper). You might need a rubber strip on the inside to direct water away when the steam hits the glass.

This entire solution costs somewhere between 4-5000,-.
The difficulty, however, is finding a door where the frame is only 45mm deep; I've only found 70mm so far...

Always hard to fully see how someone else is planning...
I'm going to build a completely ordinary wall with 70mm studs. Panel on both sides. The only difference is that I don't intend to fasten the floor batten to the floor but to press it between the floor and the ceiling, and get help with the fixation from the rubber strips (two stronger in E-profile, for example). I don't see a problem with using an ordinary wooden batten.

Then I have tiles (10x10) left over that I plan to use as a skirting on both sides and hard grout in the angle. Attaching it with silicone as you described also works (however silicone is more easily discolored than hard grout..). The wall is unlikely to move.

I've already acquired a door with a 93mm frame, so there will be a trim around it.
I don't have the issue with waterproofing since the current basement has an uninsulated concrete slab and thus only has waterproofing in the shower area and around the floor drain.

 

[nizzehult]

Apparently, the doors to a steam sauna are both tighter and have less frame depth. This one had a good price and has a 50mm frame entirely in aluminum:
https://spaprof.com/sv/category/sauna-dorrar-duschhorn/bastudorrar/matrix-angbastu-dorr

I don't have space to frame more than 45x45, if it were possible, I would go even smaller. I'm also considering whether I should instead attach the door to two aluminum square beams of the same thickness, a door weighs quite a bit, and 45x45 in wood feels weaker than the same dimension in aluminum.

I also have leftover tiles if I wanted to build a ledge, but it feels a bit unnecessary.

 

[Norrtull]

Good price on that door.