ᐅ Building a Sauna Yourself with a Sloped Ceiling – Suggestions, Tips, and Planning Advice
Created on: 24 Nov 2020 10:14
M
matte
Hello! [IMG alt=" 🙂"]https://saunabauen.de/forum/images/smilies/icon_smile.gif[/IMG]
I’d like to start this thread to get help and feedback on my plan to build a sauna myself. Of course, this thread can also be used for any topics related to sauna construction.
We decided to get a sauna, and since a prefabricated kit was not an option and a custom build was too expensive, I decided to take matters into my own hands.
When we built our house three years ago, we reserved space for a sauna at the top near the roof terrace. Unfortunately, instead of a planned flat roof, we had to install a sloped roof to get the building permit / planning permission.
This results in a roof slope with knee wall height of 1.81m (5 ft 11 in) clear height.
There is a floor area of 2.10m (83 inches) wide and 1.91m (75 inches) deep available.
The height is additionally limited by a fresh air vent on the higher side. The bottom edge of the vent is located at 2.05m (6 ft 9 in) above the finished floor level.
My idea is to build the sauna ceiling at 2.05m (6 ft 9 in) height to still be able to access this vent if necessary. According to my plan, the clear interior height inside the sauna would then be about 1.995m (6 ft 6.5 in).
The sauna will be surrounded on three sides by exterior walls (Poroton T9 masonry).
The ceiling is attached directly to the beams and vapor barrier, without counter battens. This was necessary because otherwise the terrace door would not be able to open. The architect missed that... : [IMG alt=":roll:"]https://saunabauen.de/forum/images/smilies/icon_rolleyes.gif[/IMG]
The floor is fine stoneware tiles on a screed layer with underfloor heating.
We have a three-phase power supply with 5x2.5mm² cable and a cable length of about 20m (66 ft). According to an electrician, this line should not restrict the project.
Since space is quite tight, I want to keep the wall construction as thin as possible.
Planned wall build-up:
1. Masonry with plaster
2. Vertical battens (24x48mm / 1x2 inches) with 24mm (1 inch) air gap for ventilation
3. OSB boards 15mm (0.6 inch)
4. KVH timber beams 40x60mm (1.5x2.5 inches), positioned so the 40mm (1.5 inch) side accommodates insulation
5. 40mm (1.5 inch) wood fiber insulation inside
6. No vapor barrier
7. 15mm (0.6 inch) profiled battens mounted horizontally
Now my questions:
1. Is my wall build-up feasible, or am I trying to save too much space? This would leave an interior floor dimension of nearly 1.92m x 1.75m (6 ft 3.5 in x 5 ft 9 in).
I’m 1.84m (6 ft 0.5 in) tall, so I should still have enough room to lie down comfortably.
2. We want to install a full glass door with a side panel to enjoy the outdoor view.
We plan to use 8mm (0.3 inch) tempered safety glass (ESG). Is that okay, or can this cause issues near the heater?
3. How do you connect the glass wall to the sauna structure? I thought about routing a groove around the KVH timber to set the glass in. Is that a good approach?
For the floor, I read that someone placed the glass on a silicone mat which was then trimmed flush. That sounds like a good solution to me.
3. The sauna floor area is 3.34m² (36 ft²) with an interior height of 1.995m (6 ft 6.5 in). Ignoring the slope, that gives a volume of 6.66m³ (235 ft³).
I read that for a glass door you add 1.5m³ (53 ft³) and for a glass wall the area (1.5m² / 16 ft²) multiplied by 1.2 as additional volume.
So, I’d end up with a total volume of 9.66m³ (341 ft³) and chose a 9kW heater accordingly. Does that sound right or oversized? I’m currently leaning towards the "Harvia The Wall" with external control.
4. Due to the heater’s position, there is essentially no room for a heater guard between the glass wall and heater. Is a guard necessary in a private sauna? I’m not too worried about it, but my wife is concerned.
The alternative would be to shift the lower bench slightly under the upper bench and move the heater, which would create space for a guard.
Alternatively, there is a glass protective shield with integrated lighting available that mounts in front of the heater. Would that be enough? I’m not too keen on wooden guards though... [IMG alt=";)"]https://saunabauen.de/forum/images/smilies/icon_wink.gif[/IMG]
5. A coworker recommended bench heights of 60cm and 120cm (24 and 47 inches). That would cause problems with the sauna height. I was thinking about 45cm and 90cm (18 and 35 inches) instead. Since we don’t want it very hot anyway, I see no reason for higher benches.
6. To avoid further reducing the roof slope height, I considered skipping the OSB boards there and mounting the KVH beams directly at a 24mm (1 inch) gap (batten distance) from the ceiling. Any issues with that?
7. We prefer the look of horizontally mounted profiled battens. Any objections? Given the tight space, I would skip additional rear ventilation. From what I’ve read, that’s not strictly necessary.
8. In my case, would it be better to use a different insulation material with a vapor barrier instead of wood fiber insulation?
9. The left wall with the glass door will be clad on the outside with profiled wood boards as well. This way I could install an access panel above the sauna to reach the fresh air vent if needed. Also, I could place the electronics for lighting and audio on the ceiling, making them accessible.
Can I mount the cladding boards directly on the KVH beams, or is an additional counter batten or similar required?
I want the wall to finish flush with the terrace door frame. To prevent the terrace door (especially the handle) from hitting the wall, I plan to install a stopper mounted on the KVH timber there.
That’s it for now. I’m curious what you think about my plan. I hope my post is not too long... [IMG alt=":?"]https://saunabauen.de/forum/images/smilies/icon_confused.gif[/IMG]
I’m attaching some pictures to show the current planning status. If you need more info, just ask.
Looking forward to any feedback [IMG alt=";)"]https://saunabauen.de/forum/images/smilies/icon_wink.gif[/IMG]
Thanks in advance!
Best regards
I’d like to start this thread to get help and feedback on my plan to build a sauna myself. Of course, this thread can also be used for any topics related to sauna construction.
We decided to get a sauna, and since a prefabricated kit was not an option and a custom build was too expensive, I decided to take matters into my own hands.
When we built our house three years ago, we reserved space for a sauna at the top near the roof terrace. Unfortunately, instead of a planned flat roof, we had to install a sloped roof to get the building permit / planning permission.
This results in a roof slope with knee wall height of 1.81m (5 ft 11 in) clear height.
There is a floor area of 2.10m (83 inches) wide and 1.91m (75 inches) deep available.
The height is additionally limited by a fresh air vent on the higher side. The bottom edge of the vent is located at 2.05m (6 ft 9 in) above the finished floor level.
My idea is to build the sauna ceiling at 2.05m (6 ft 9 in) height to still be able to access this vent if necessary. According to my plan, the clear interior height inside the sauna would then be about 1.995m (6 ft 6.5 in).
The sauna will be surrounded on three sides by exterior walls (Poroton T9 masonry).
The ceiling is attached directly to the beams and vapor barrier, without counter battens. This was necessary because otherwise the terrace door would not be able to open. The architect missed that... : [IMG alt=":roll:"]https://saunabauen.de/forum/images/smilies/icon_rolleyes.gif[/IMG]
The floor is fine stoneware tiles on a screed layer with underfloor heating.
We have a three-phase power supply with 5x2.5mm² cable and a cable length of about 20m (66 ft). According to an electrician, this line should not restrict the project.
Since space is quite tight, I want to keep the wall construction as thin as possible.
Planned wall build-up:
1. Masonry with plaster
2. Vertical battens (24x48mm / 1x2 inches) with 24mm (1 inch) air gap for ventilation
3. OSB boards 15mm (0.6 inch)
4. KVH timber beams 40x60mm (1.5x2.5 inches), positioned so the 40mm (1.5 inch) side accommodates insulation
5. 40mm (1.5 inch) wood fiber insulation inside
6. No vapor barrier
7. 15mm (0.6 inch) profiled battens mounted horizontally
Now my questions:
1. Is my wall build-up feasible, or am I trying to save too much space? This would leave an interior floor dimension of nearly 1.92m x 1.75m (6 ft 3.5 in x 5 ft 9 in).
I’m 1.84m (6 ft 0.5 in) tall, so I should still have enough room to lie down comfortably.
2. We want to install a full glass door with a side panel to enjoy the outdoor view.
We plan to use 8mm (0.3 inch) tempered safety glass (ESG). Is that okay, or can this cause issues near the heater?
3. How do you connect the glass wall to the sauna structure? I thought about routing a groove around the KVH timber to set the glass in. Is that a good approach?
For the floor, I read that someone placed the glass on a silicone mat which was then trimmed flush. That sounds like a good solution to me.
3. The sauna floor area is 3.34m² (36 ft²) with an interior height of 1.995m (6 ft 6.5 in). Ignoring the slope, that gives a volume of 6.66m³ (235 ft³).
I read that for a glass door you add 1.5m³ (53 ft³) and for a glass wall the area (1.5m² / 16 ft²) multiplied by 1.2 as additional volume.
So, I’d end up with a total volume of 9.66m³ (341 ft³) and chose a 9kW heater accordingly. Does that sound right or oversized? I’m currently leaning towards the "Harvia The Wall" with external control.
4. Due to the heater’s position, there is essentially no room for a heater guard between the glass wall and heater. Is a guard necessary in a private sauna? I’m not too worried about it, but my wife is concerned.
The alternative would be to shift the lower bench slightly under the upper bench and move the heater, which would create space for a guard.
Alternatively, there is a glass protective shield with integrated lighting available that mounts in front of the heater. Would that be enough? I’m not too keen on wooden guards though... [IMG alt=";)"]https://saunabauen.de/forum/images/smilies/icon_wink.gif[/IMG]
5. A coworker recommended bench heights of 60cm and 120cm (24 and 47 inches). That would cause problems with the sauna height. I was thinking about 45cm and 90cm (18 and 35 inches) instead. Since we don’t want it very hot anyway, I see no reason for higher benches.
6. To avoid further reducing the roof slope height, I considered skipping the OSB boards there and mounting the KVH beams directly at a 24mm (1 inch) gap (batten distance) from the ceiling. Any issues with that?
7. We prefer the look of horizontally mounted profiled battens. Any objections? Given the tight space, I would skip additional rear ventilation. From what I’ve read, that’s not strictly necessary.
8. In my case, would it be better to use a different insulation material with a vapor barrier instead of wood fiber insulation?
9. The left wall with the glass door will be clad on the outside with profiled wood boards as well. This way I could install an access panel above the sauna to reach the fresh air vent if needed. Also, I could place the electronics for lighting and audio on the ceiling, making them accessible.
Can I mount the cladding boards directly on the KVH beams, or is an additional counter batten or similar required?
I want the wall to finish flush with the terrace door frame. To prevent the terrace door (especially the handle) from hitting the wall, I plan to install a stopper mounted on the KVH timber there.
That’s it for now. I’m curious what you think about my plan. I hope my post is not too long... [IMG alt=":?"]https://saunabauen.de/forum/images/smilies/icon_confused.gif[/IMG]
I’m attaching some pictures to show the current planning status. If you need more info, just ask.
Looking forward to any feedback [IMG alt=";)"]https://saunabauen.de/forum/images/smilies/icon_wink.gif[/IMG]
Thanks in advance!
Best regards
Schimi17913 Jan 2021 09:15Well ... what a coincidence 🙂
I faced the same question at our place. We had the vapor retarder installed by a professional company. They said it’s not absolutely necessary, but of course, it doesn’t hurt. I then did it in EL.
For you, the effort should be manageable. The important thing is to properly seal the edges. We used an adhesive from a cartridge.
I faced the same question at our place. We had the vapor retarder installed by a professional company. They said it’s not absolutely necessary, but of course, it doesn’t hurt. I then did it in EL.
For you, the effort should be manageable. The important thing is to properly seal the edges. We used an adhesive from a cartridge.
I’ve now spoken with two people who each built their own sauna, and both said it’s not necessary. We’ll see. The joints will simply be sealed with the matching aluminum tape.
I’m starting to agree with @pagoni2020—you can definitely overdo it 😉 In the end, it’s just a sweat lodge, nothing more, but also nothing less.
What’s bothering me more right now is that I have to start installing the profile boards horizontally from the top, because the recommendation is that the groove should always face down to prevent moisture from collecting. Since the profile wood clips have to go into the groove, I can’t start from the bottom. For the top boards, I need to use the circular saw because I can’t cut them with the miter saw. But the saw isn’t arriving until the end of next week… 🙁
I’m starting to agree with @pagoni2020—you can definitely overdo it 😉 In the end, it’s just a sweat lodge, nothing more, but also nothing less.
What’s bothering me more right now is that I have to start installing the profile boards horizontally from the top, because the recommendation is that the groove should always face down to prevent moisture from collecting. Since the profile wood clips have to go into the groove, I can’t start from the bottom. For the top boards, I need to use the circular saw because I can’t cut them with the miter saw. But the saw isn’t arriving until the end of next week… 🙁
Schimi17913 Jan 2021 11:27Then I did get the correct information back then. However, I once read online that it is recommended to do it. But of course... some things can be overdone... 🙂
P
pagoni20203 Jan 2021 13:27I would go by my instinct and could even imagine sealing it with leftover aluminum tape. However, as I said, this would probably be more a matter of personal feeling or preference rather than a technical requirement.
Whether or what might actually be technically relevant could only be seen if something like this were taken apart after 10-15 years. I don’t think there would be anything serious to find, or rather something entirely different. I’m not a fan of doing everything three times over just to rule out every theoretically possible worst-case scenario.
For a long time, I worked with someone who did a lot of work on and around our house (including the sauna) and taught me that many things can be done simpler without being worse.
When it comes to the sauna, you should also consider how you use it individually. A commercial provider, for example, has to build it so it can withstand continuous or extreme use. As a private person, I know that I might use the sauna twice a week and generally take care regarding moisture, mold, etc., and always ventilate. The amount of moisture produced during sauna sessions is not enough to get behind the cladding, pass through tiny gaps, and cause long-term damage there.
I even believe that in your cladding, the groove could probably be the other way around without causing any problems. When you use the sauna, the wood on the wall is never wet, not even with a steam sauna.
I can understand that you feel better doing it that way, and that’s fine—I know the feeling of being more comfortable with it. Whether that is truly necessary, we don’t know.
It’s going to be great for you!!!
Whether or what might actually be technically relevant could only be seen if something like this were taken apart after 10-15 years. I don’t think there would be anything serious to find, or rather something entirely different. I’m not a fan of doing everything three times over just to rule out every theoretically possible worst-case scenario.
For a long time, I worked with someone who did a lot of work on and around our house (including the sauna) and taught me that many things can be done simpler without being worse.
When it comes to the sauna, you should also consider how you use it individually. A commercial provider, for example, has to build it so it can withstand continuous or extreme use. As a private person, I know that I might use the sauna twice a week and generally take care regarding moisture, mold, etc., and always ventilate. The amount of moisture produced during sauna sessions is not enough to get behind the cladding, pass through tiny gaps, and cause long-term damage there.
I even believe that in your cladding, the groove could probably be the other way around without causing any problems. When you use the sauna, the wood on the wall is never wet, not even with a steam sauna.
I can understand that you feel better doing it that way, and that’s fine—I know the feeling of being more comfortable with it. Whether that is truly necessary, we don’t know.
It’s going to be great for you!!!
Schimi17913 Jan 2021 13:55Well... an extensive sauna day with several infusions and temperatures above 80°C (176°F) definitely produces a lot of moisture in my opinion 🙂
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