What Material to Build a House Float?

Discussion in 'Boat Design' started by FloatHomeHelp, Nov 24, 2012.

  1. FloatHomeHelp
    Joined: Oct 2012
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    Location: Nova Scotia Canada

    FloatHomeHelp Float Home Help?

    Hey guys, I've been creeping on this forum for a while trying to learn and absorb everything I can, but now I need to harness your collective knowledge for my specific project. I apologize in advance for the long post, I just want to be detailed so the advice can be targeted.

    I've decided to build a floating home from scratch. I'm based in Nova Scotia Canada, Although there is coastline and lakes everywhere, there are no year-round floating dwellings. To my knowledge, this will be the first.

    The home will be next to a dock/wharf on a small piece of rural land I buy, not at a marina. It will need to have large storage tanks both for freshwater and grey-water.

    I am considering both freshwater lakes and very protected saltwater coves/inlets. Based on the many lots I've gone to view so far I think 3ft is the maximum draft I can have. Less is better, the lakes seem shallow and if I go salt water I don't want it to touch down at low tide.

    The biggest question I'm looking for help with right now is: What material should I build the float out of? The float will either need to be constructed on the small, rural waterfront lot. Or built at a shop in sections small enough to truck to the site.

    The current float of my dreams would be in the range of 30'X40' with a 22'X24' 1.5 story house build on top of it.

    Right now the thought is to build three rectangle barges 4'X10'X40'. Truck them to the location, launch them and hook them together in the water therefore making one big floating platform. I would prefer for this platform to have positive buoyancy so I would like to fill all of the open area (the space not taken up by structural supports or water tanks) with foam of somekind. Better insulation as a bonus (it's cold up here :p)

    Based on my slightly conservative calculation I should be able to float about 220,000lbs while keeping one foot freeboard. (if that's the right term to mean top of float to the waterline) Less than that would make me nervous.

    So rough guesses of the weight I'll need to float:
    75,000 to 95,000 lbs (house structure, including live load)
    30,000lbs to 45,000lbs (possible snow load)
    10,00lbs to 13,000lbs (water holding tanks)
    Plus the big unknown: the weight of the float itself. (also considering placing ballast tanks in the corners to help with level/balance)

    So that's where I'm at. I want to make this out of something that I can afford and that will last as long as possible with the least amount of maintenance. Chances are I will not ever be able to take it out of the water until it is time to tear it apart.

    Options I'm currently considering:

    Concrete
    Steel
    Aluminum
    Plywood with fibreglass (or whatever covering makes most sense)
    Plastic Barrels

    I'm also open to any other option that maybe I haven't thought about. I do hope to get insurance on this as it will be my only home.

    I appreciate your wisdom. What do you think?
     
  2. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    FHH welcome to the board.

    Many float homes out west here-I looked into floating homes before,but made no sense as I have a condo and a bigger boat.
    I'm no expert but some ideas you may or may not have looked into:

    -float homes out here usually have more than a foot of freeboard,even in protected areas.
    -look into provincial regs
    -there's a company here that builds floats and ships all over the world- basically a shotcreted ferro barge with a poly styrene core. Zero maintenance,never sink.IMF I think-google it. About the only/best use for ferro AFAIC.How I'd build one.
    -the older ones used cedar logs as floats

    Google something like- BC floating homes.


    http://www.youtube.com/watch?v=4suoDPC0ip8
     
  3. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    If it's not going anywhere, sink some piles, barge in a mfg home with frame/decks attached, and bolt her up at high tide. Drive the barge away at low tide. The good news here is that you can hardpipe everything to land and stick your service equipment in a shed.

    You could buy a few "park model" trailers and set them up individually to form a little enclave and run decks between them. They do something like that at some tropical resorts.

    Considering your location, you might consider setting up a decent refer unit, and build on packed ice. You could pay the power bill with fish/game storage. you'd just need a 6" foam shell to pack with ice. A 1/6 acre should give reasonable motions, I should think.:D

    If you build up a big enough stockpile this the winter, you should last through the summer. Any college kids looking for a design project???
     
  4. rasorinc
    Joined: Nov 2007
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    Location: OREGON

    rasorinc Senior Member

    Float home

    Eric Sponberg, a N.A. on this forum located in Florida has designed several homes of the type you are considering building. While I'm a WOOD man 100%
    I can not recomend wood for a home that may never come out of water. Even steel has to have maintenance. That leaves a composite for your usage. I now nothing about cement as a long term hull. You might send a message to Eric asking him to reply to your posting as he has vast experience. Good luck, and welcome.
     
  5. FloatHomeHelp
    Joined: Oct 2012
    Posts: 9
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    Location: Nova Scotia Canada

    FloatHomeHelp Float Home Help?

    Thanks all for the warm welcome.

    WestVanHan:
    -Good point about the freeboard perhaps I should look at more examples.
    -Are there usually provincial regs about boatbuilding materials?
    -I attempted to contact IMF sometime ago, no response. I think they are building floats right but have the feeling that it's not in my budget. I'll try to connect with them again.
    -Big Cedar logs are hard to come by on the east coast, thought about having a log home building company ship them in for me but it looks like they are going for over $1000.00 per log! Plus they need to be replaced or added to after about 20years.

    PhilSweet
    -I definitely wanna stick with building the house, hoping to custom design it for site/my lifestyle as much as budget will allow.
    -I would love to use piles but I'm under the impression that they are not allowed in all waterways. I'll have to learn more about this. Also, many of the lakes I'm considering are solid bedrock bottoms. I wonder if that would pose a problem?
    -Contacting a college/university is an awesome idea. I'll follow through with that.

    rasorinc
    -Thanks for the lead on Eric, I'll reach out to him!
     
  6. rasorinc
    Joined: Nov 2007
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    Location: OREGON

    rasorinc Senior Member

    Float home

    If you want a "custom home" on a floating platform, remember one thing.
    You really do not want flex in the hull. No earth quakes like on land, waves are OK. The whole hull has to move as one piece.
     
  7. FloatHomeHelp
    Joined: Oct 2012
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    Location: Nova Scotia Canada

    FloatHomeHelp Float Home Help?

    Good point. One idea I had to join the sections together is to place steel I-beams across all three floats directly under where the exterior walls of the house would sit.

    Is anyone out there interested in seeing the rough elevation sketches I've done so far? Maybe that would help give advice on materials and point out parts of my design that could be problematic.
     
  8. ytquest
    Joined: Oct 2005
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    Location: Hendersonville,Tn.

    ytquest Junior Member

    Floathomehelp,
    I own a floating home in clarksville,TN. That was built in 1971 on steel pontoons (not the best material) and sealed with cold tar epoxy paint. The original builder-owner had large holding and water tanks (steel) mounted in the center of the structure toward the aft for balancing the added weight of a large pilot house forward. It is a stick framed shotgun layout of 1240 Sq. ft.
    Although it dose float all the time as winter pool lets the water down several feet and spring floods raise it 5 to 20 ft. i don't have to worry about losing my home or personal property to floods.
    I would think about fiberglass and plywood, just don't skimp on the glass cloth layers or gel-coat and seal the inside with resin.
    Just remember everything must be serviced eventually.
     
  9. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    Probably rules and regulations. Best ask a pro.

    many Floating docks use Foam billets for buoyancy. Might be good for a quick and dirty small floating house. http://www.fpcfoam.com/buoyancy.html

    Industrial floating docks are made of steel reinforced concrete. Ferro cement...might be worth studying.
     
  10. FloatHomeHelp
    Joined: Oct 2012
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    Location: Nova Scotia Canada

    FloatHomeHelp Float Home Help?

    ytquest, Thanks for your response. Have you (or the pervious owner) had to take the house out of the water to service? It's a good and true point you make that everything must be serviced eventually. I guess my goal is to try to understand timeframes for different materials to determine an educated estimate of how long eventually is.

    I like the idea of wood and resin because the tools to work with it are readily available and the weight of the float itself would likely be much less than concrete or steel. Probably a little cheaper too. Do you think I can get a real lifespan out of it? If I buy high quality materials and take my time with many well applied layers is it realistic to expect 30 to 40 years out of it?

    What is the main reason why you would advice against steel?
     
  11. ytquest
    Joined: Oct 2005
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    Location: Hendersonville,Tn.

    ytquest Junior Member

    Yes, I suggested this material because it sounds like you are looking to build in the out back areas. Using marine ply will save problems with internal rot.
    rasorinc has a valid point to build a solid frame to hold your pontoons as one ridged structure.
    Mine are held together with 24" center floor beams and the pontoons welded together. When it lost some of the leveling dun-age for when it has to rest on the bottom it broke some of the welds causing floor buckling in one room. I had to re-level and pour a platform for to rest on. Where ever you decide to build check on high and low water levels and government codes. They classified my home as a house-boat.
    As I said before mine is steel and 41 years old with no major rust problems or leaks.
    Good luck !
     
  12. ytquest
    Joined: Oct 2005
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    Location: Hendersonville,Tn.

    ytquest Junior Member

    Floathomehelp, forgot to let you know that the marina office at my marina where I keep my boats is made of fiberglass covered ply, and has floated a 1100 sq ft two story for 48 years.
    There only problem has been in the last few years with small leaks where the glass was applied thin on corners.
     
  13. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    I forgot about Eric-he's the one.

    I recall seeing a barge made out of those blue or white 200 litre plastic barrels. Somehow contained in rows, build an inverted box and keep them from rub wear,don't know how long they'd last,etc.
    You'd need to do more research.
    But at $5 each... or free from the right source the price is right. Try google.
     
  14. FloatHomeHelp
    Joined: Oct 2012
    Posts: 9
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    Location: Nova Scotia Canada

    FloatHomeHelp Float Home Help?

    Thanks for your help guys.

    -does any one know a good learning resource (book,website, smart human) where I can learn the ins and outs of best types of marine plywood and techniques for applying fiberglass + resin?

    -I've reached out to Eric Via email I'm hoping he has time/interest in pointing me in the right direction.
     

  15. Submarine Tom

    Submarine Tom Previous Member

    FHH!

    Welcome indeed.

    I have built my own houseboat (not a floathome) here on the west coast of Canada.

    Your question is a good one and thus far I would agree with the advice offered.

    To me the biggest qualifier to the answer you seek is: What's the budget?

    If I were to do it over, I'd build a steel hull.

    Mine is fiberglas on plywood on 2X6 frames.

    Another option is to buy a used barge, then you could even have a garden!

    I don't know your area well at all but I would find out why there aren't any floathomes around.

    You're also going to want to know the requirements to build to BEFORE you go buy your insurance.

    If I had waterfront property, I'd be building my dream home on shore and tie my dream boat up to the dock, but that's me.

    Have you ever tried to sleep on a boat during a storm?

    Living on the water is magical but the reality/fantasy ratio can be sobering.
     
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