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
In their defense, I should add that the item in their shop is called "ASPEN BENCH SLAT FOR THE FRONT SIDE SHA 80x108x2100mm" and the technical details also list a width of 108mm (4.25 inches) and a thickness of 80mm (3.15 inches).
So I could have realized that earlier. Who really trusts a technical drawing anyway :p
Anyway, the cladding will just shift about 28mm (1.1 inches) forward, leaving the lower bench with a lying surface width of 76cm (30 inches), which no one cares about... 😉
Anything else would mean a massive amount of effort to redesign, which I’m not willing to do.
I think I’m just being too precise again anyway ^^
So I could have realized that earlier. Who really trusts a technical drawing anyway :p
Anyway, the cladding will just shift about 28mm (1.1 inches) forward, leaving the lower bench with a lying surface width of 76cm (30 inches), which no one cares about... 😉
Anything else would mean a massive amount of effort to redesign, which I’m not willing to do.
I think I’m just being too precise again anyway ^^
P
pagoni202029 Jan 2021 15:35Do you even need the board at the bottom, or am I misunderstanding something?
Although... it actually looks good, like it was intended that way!!!
Although... it actually looks good, like it was intended that way!!!
The substructure for the benches is mostly finished.
Unfortunately, I ran out of brackets and screws.
I'm still unsure whether to add one or two supports down to the floor as a precaution—I’m worried everything might collapse. Although it does look pretty cool like this, without any...
Fortunately, I installed the conduits for the lighting correctly. It would have been a problem if they were visible later on.
Unfortunately, I ran out of brackets and screws.
I'm still unsure whether to add one or two supports down to the floor as a precaution—I’m worried everything might collapse. Although it does look pretty cool like this, without any...
Fortunately, I installed the conduits for the lighting correctly. It would have been a problem if they were visible later on.
I’ve now screwed perforated metal plates underneath the joints. A few brackets are still missing, but the frame is already so stable that we can probably skip adding legs.
For attaching the walls, I used 5x100mm (4 inch) Spax screws, and I still have some left. So far, I’ve been spacing them about 20cm (8 inches) apart, but I think I’ll reduce that spacing with the remaining screws—better safe than sorry.
Two of us have already sat on it, and apart from a slight bending of the front edge, not much happens. The bench slats should further stabilize it and, most importantly, distribute the load better so it won’t be concentrated in just one spot.
Tomorrow, I want to start on the bench slats. I’ve ordered matching 10mm (0.4 inch) spacer wedges, so everything should come out nice and even. They just need to arrive now 😉
Now a question:
The squared timber has an edge length of 52mm (2 inches), and the bench slats are 28mm (1 inch) thick, so together that’s 80mm (3.1 inches). I bought 4x70mm (2.75 inch) Spax screws for fastening from underneath.
The bench slats are 120mm (4.7 inches) wide. How often would you screw them down? Once per beam or twice? For the long slats across the entire width, that means 5 or 10 screws in total.
I was originally planning just one screw per beam, centered, but I’m a bit worried the slats might start to warp over time? Hope you understand what I mean...
What about pre-drilling? Would you skip it completely, only pre-drill the beams, or also drill slightly into the bench slats? My gut says I’d pre-drill the beams, but I’m skeptical whether the bench slats might crack if drilled... 😕
There’s also an update on the odyssey with Saunainter from Estonia.
After those idiots informed me on 02/02 that the shipment had been sent (even though it had already been with me for 8 days), they offered me a refund in my PayPal case—but for the full amount.
I’ve now only returned the sauna control unit and am curious how the refund will be handled.
They really manage to do everything wrong that can possibly go wrong 🙄
For attaching the walls, I used 5x100mm (4 inch) Spax screws, and I still have some left. So far, I’ve been spacing them about 20cm (8 inches) apart, but I think I’ll reduce that spacing with the remaining screws—better safe than sorry.
Two of us have already sat on it, and apart from a slight bending of the front edge, not much happens. The bench slats should further stabilize it and, most importantly, distribute the load better so it won’t be concentrated in just one spot.
Tomorrow, I want to start on the bench slats. I’ve ordered matching 10mm (0.4 inch) spacer wedges, so everything should come out nice and even. They just need to arrive now 😉
Now a question:
The squared timber has an edge length of 52mm (2 inches), and the bench slats are 28mm (1 inch) thick, so together that’s 80mm (3.1 inches). I bought 4x70mm (2.75 inch) Spax screws for fastening from underneath.
The bench slats are 120mm (4.7 inches) wide. How often would you screw them down? Once per beam or twice? For the long slats across the entire width, that means 5 or 10 screws in total.
I was originally planning just one screw per beam, centered, but I’m a bit worried the slats might start to warp over time? Hope you understand what I mean...
What about pre-drilling? Would you skip it completely, only pre-drill the beams, or also drill slightly into the bench slats? My gut says I’d pre-drill the beams, but I’m skeptical whether the bench slats might crack if drilled... 😕
There’s also an update on the odyssey with Saunainter from Estonia.
After those idiots informed me on 02/02 that the shipment had been sent (even though it had already been with me for 8 days), they offered me a refund in my PayPal case—but for the full amount.
I’ve now only returned the sauna control unit and am curious how the refund will be handled.
They really manage to do everything wrong that can possibly go wrong 🙄