Swimming pool on garage roof

Discussion in 'Renovation & Home Improvement' started by The lucky duck, 24th May, 2020.

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  1. The lucky duck

    The lucky duck Well-Known Member

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    Hi

    we are going to put in a double garage and have the opportunity to put a pool on top.

    has anyone done this?

    any lessons learned?

    how much did it cost you?
     

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  2. vbplease

    vbplease Well-Known Member

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    I can’t say I’ve done it, but love the idea of it. It combines two structures in one and would save on excavation costs and soil disposal..
    from an engineering and construction point of view I don’t think it would be too involved.. having said that I think most domestic builders (who don’t build suspended concrete slabs) would perceive it as building the Taj Mahal.. I’d look for a builder who regularly builds suspended concrete, or a commercial builder.

    You can achieve eye watering spans with suspended concrete.. this one, featured on grand designs spanned 14m Grand Designs Australia: Hunters Hill Textural House - Completehome
     
  3. wylie

    wylie Moderator Staff Member

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    Love this idea. Is this in Brisbane? I know someone who could do this or at least price it.
     
  4. The lucky duck

    The lucky duck Well-Known Member

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    Yes in Brisbane. We have a lovely view. Could you send me the details?
     
  5. Scott No Mates

    Scott No Mates Well-Known Member

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    A typical pool holds 50,000 litres of water, this weighs roughly 50t.

    There's approximately 20 m³ of concrete in the pool as well, another 32t without considering the structural support required to hold up the pool or any requirements for stability or earthquake proofing the stducture.

    Your architect has their head in the clouds and a hand in your back pocket.

    The concept sounds great but support from the ground will be much more cost effective.
     
  6. The lucky duck

    The lucky duck Well-Known Member

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    The views not as good at ground level. How much do you think it will be?
     
  7. datto

    datto Well-Known Member

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    Each cubic metre of water weighs one tonne. You could have 25 tonnes of water on your garage.

    with that weight you gonna need some heavy duty reinforcement which no doubt will cost some coin.

    An uneducated guess is an extra $100K on your house build just for the pleasure of some private bathing.

    Or perhaps the water could be used to cultivate some exotic vegetation:D There’s plenty of sun up there lol.
     
  8. Elives

    Elives Well-Known Member

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    standard pool build is 25-35k? so i'd say 50-75k
     
  9. Scott No Mates

    Scott No Mates Well-Known Member

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    I have a much thicker pencil and wouldn't expect any change from $250k If you were at Inala, so add the location margin. Then you need to allow to finish the pool, landscaping, fencing, aprons etc.
     
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  10. Blueskies

    Blueskies Well-Known Member

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    We are getting quotes for pools at the moment, an inground concrete pool with fairly standard features is coming back about 50k.

    No way you would get something like that design for anything under $100k, i would hazard closer to $150 for the serious structural support required.
     
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  11. vbplease

    vbplease Well-Known Member

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    As noted above the engineering is nothing special.. the weight of the water and concrete structure won’t come close to the capacity of a 190thick core filled block wall support, and the square shape is inherently rigid, so lateral stability is not as issue.. the only issue might be if you have crap soil/steep slope, so there might be some extra dollars in the footings.

    A builder may be reluctant to give you a ballpark figure without engineering drawings. Have you got a site classification? (Soil test)
    Sketch from an architect?
    I’d take these details to a structural engineer for them to do a sketch for a builder to put a number too.. a builder who is familiar with suspended concrete, otherwise you’ll get silly quotes.
     
  12. The Y-man

    The Y-man Moderator Staff Member

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  13. Doncossack75

    Doncossack75 New Member

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  14. datto

    datto Well-Known Member

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    OK what if it’s a fibreglass pool. Much less weight, less cost.
     
  15. wylie

    wylie Moderator Staff Member

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    Let me send him the photo and get back to you.
     
  16. wylie

    wylie Moderator Staff Member

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    Give Rosco a call on 0418 884 970. I've seen some of his pools. Amazing.
     
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  17. shorty

    shorty Well-Known Member

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    How reactive is your soil?
     
  18. Something_Wrong

    Something_Wrong Well-Known Member

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    Yeah a fiberglass pool with Concrete pre cast or formed panels to give the look af a concrete pool.

    Once the Ground is worked out, you could also do a Post Tensioned roof and ground slab to save on concrete thickness but still have the capacity for loading.

    It wont be a cheap exercise our above ground concrete pool cost $58k add all the extras to your and I would say with the Garage and Pool you would be close to $130k
     
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  19. Lacrim

    Lacrim Well-Known Member

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    I'd be too chicken to use that garage. Be parking my car on the street:eek:
     
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  20. vbplease

    vbplease Well-Known Member

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    I originally thought the same, although I don't think a PT slab would work in this case.. it's typically designed for a constant static load. There would be such a big difference between the pool being full and empty that the post tensioning could damage the slab prior to the water going in, and if it were emptied for whatever reason.
    I was thinking along this lines too.. for a double garage 6m x 6m all up, no change out of $100k assuming the foundation material doesn't require piers.