Hi,
We built our own wooden hot tub this summer (our house in Sweden we just finished building earlier in the year). ~1.6m diam using 45mm thick staves (width ~140mm), total height ~1.5m. We had the boards cut at a local timber mill and milled convex/concave locally too. Capacity 1800L. Secured by two steel compression bands. Is now water tight (the miracle of sawdust . Used three marine drains (1inch bsp fittings) for suction, supply and overflow. I built my own control system, but that's another story. Frost protected in winter by keeping it at ~7.5^c. See early photo of it (pipes are now replaced with insulated MLC). Built it half submerged into decking on a concrete base, and insulated by a layer of "wood wool" boards under the base.
Problem is, we need to insulate it for the winter. We have some 110mm wide tongue and grove facade boards we want to circle around the outside of the hottub and leave a ~10cm void in the middle that we will fill with perlite insulation (which can handle the moisture) and which is also left over from the build (we used perlite to insulate under the slab), calculated about 0.34 cubic m of it required.
Question is, I haven't quite figured out the best way to mount the facade boards. We don't want to secure them to the hottub timber itself (we avoided screws, fittings, etc so far). The facade boards are the full height of the staves. We realise that in a circular arrangement the tongue and gooves will not fit together properly, but that is okay. We also trying to use left over timber from our build (which the facade boards are). The facade boards are nailed onto our house, so we like to use nails again to mount them for consistency. We already built some benches on the terrace using facade boards as the lining.
One thought I had was to use some wide planks (say, 200mm and say 1-2inches thick or something) and cut a series of arcs (that snug onto the side of the hottub), then circle those arcs around the tub and tighten them together (may use screws to join the arcs), and do this in two locations, close to the base and about 20cm from the top. The facade boards can then nailed around onto the arcs. Once the boards are in, we will fill it with perlite. This solution though might consume a decent amount of planks (haven't figure out the calculations)
That's the only solution I can think of so far. Can anyone suggest other ideas?
(we will build a ledge around the top once the facade boards are in, and we have to figure out how to make an insulated cover - I try to convince my partner to use mylar as an option in the cover although it is plastic and our build is largely plastic free (we used a non-plastic vapour barrier and wood/paper based insulation).
Thanks ...
(edit: I found a photo of the facade boards ...)
We built our own wooden hot tub this summer (our house in Sweden we just finished building earlier in the year). ~1.6m diam using 45mm thick staves (width ~140mm), total height ~1.5m. We had the boards cut at a local timber mill and milled convex/concave locally too. Capacity 1800L. Secured by two steel compression bands. Is now water tight (the miracle of sawdust . Used three marine drains (1inch bsp fittings) for suction, supply and overflow. I built my own control system, but that's another story. Frost protected in winter by keeping it at ~7.5^c. See early photo of it (pipes are now replaced with insulated MLC). Built it half submerged into decking on a concrete base, and insulated by a layer of "wood wool" boards under the base.
Problem is, we need to insulate it for the winter. We have some 110mm wide tongue and grove facade boards we want to circle around the outside of the hottub and leave a ~10cm void in the middle that we will fill with perlite insulation (which can handle the moisture) and which is also left over from the build (we used perlite to insulate under the slab), calculated about 0.34 cubic m of it required.
Question is, I haven't quite figured out the best way to mount the facade boards. We don't want to secure them to the hottub timber itself (we avoided screws, fittings, etc so far). The facade boards are the full height of the staves. We realise that in a circular arrangement the tongue and gooves will not fit together properly, but that is okay. We also trying to use left over timber from our build (which the facade boards are). The facade boards are nailed onto our house, so we like to use nails again to mount them for consistency. We already built some benches on the terrace using facade boards as the lining.
One thought I had was to use some wide planks (say, 200mm and say 1-2inches thick or something) and cut a series of arcs (that snug onto the side of the hottub), then circle those arcs around the tub and tighten them together (may use screws to join the arcs), and do this in two locations, close to the base and about 20cm from the top. The facade boards can then nailed around onto the arcs. Once the boards are in, we will fill it with perlite. This solution though might consume a decent amount of planks (haven't figure out the calculations)
That's the only solution I can think of so far. Can anyone suggest other ideas?
(we will build a ledge around the top once the facade boards are in, and we have to figure out how to make an insulated cover - I try to convince my partner to use mylar as an option in the cover although it is plastic and our build is largely plastic free (we used a non-plastic vapour barrier and wood/paper based insulation).
Thanks ...
(edit: I found a photo of the facade boards ...)
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