Does anyone have experience building boathouses in lakes that will freeze? Currently pricing a double slip boathouse with a concrete foundation and a finished room above. The plans call for an 8″ poured concrete perimeter wall around the slip and then around the outside of the building. The walls are 4′ apart to create a walkway around the slip.Think of it as a “C” facing the lake. Plans call for crushed gravel fill between the walls capped of with a 4″ concrete walk.Getting conflicting info on the “fill” as some are suggesting solid concrete in the fill area because water from the lake could penetrate the concrete and freeze causing the concrete to fail.Any advise would be appreciated.
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I am in Lake Placid, NY, and the lakes all around here have old and new boathouses on them. Lots.
Caissons are sunk down to rock in the lake, and concrete piers built atop the caissons, for supporting a structural steel base typically made of square or rectangular tubing. The boathouses have large overhead doors for each boat slip, and the boathouse floors stick out like fingers between the slips. The back quarters or halves bear on shoreline, usually rock, where piers are built that are drilled into the rock.
I have only seen this done on lakes where the flow is controlled by dams or locks, so that lake levels fluctuate little or not at all.
Our wintertime low temps can get as low as -55 in worst cases, and ice thicknesses of 8 or more inches are common.
The boathouses are built atop the fabricated steel bases, and side and front elevations have structure and finish that comes down to 6 inches or so above high water mark.
Here is a pic of one, just getting started. The structural steel has had the wood framing bolted on.
Here is a finished one. I think it is the one with the timber frame.
Edited 10/4/2006 10:01 pm ET by Gene_Davis
Edited 10/4/2006 10:03 pm ET by Gene_Davis
hamjob,
Be aware that building a boat house is complex not only from a structural point but also from a political point..
It does no good what-so-ever to have a building permit in hand if someone else has jurisdiction..
The city/county whatever may issue the permit, only to have the DNR, fisheries division, or whoever shut you down.. ON my lake there are nine differant government bodies that control the lake.. (Not counting the various cities that abutte the lake)..
Once you've cleared all of those hurdles there is the structural matter to resolve..
Hydrodynamically there is tremendous force in a frozen lake.. think of it as a really big dynomite explosion in really slow motion..
When water freezes it expands a lot!
Look at a tray of ice cubes in your feezer.. You could have sworn that when you put the water in the freezer it was flat and now that it's frozen it has peaks! The tray they are made is is very flexible or would be completely torn apart..
In addition when the ice goes out in the spring, wind drives the ice with real power. Think of the biggest bulldozer you've ever seen.. a high wind right into the boat house and you will see total destruction..
That's the sort of engineering that is involved..
My old house had a boat house and while various govermental bodies tried to force me to remove it, the ice did it's thing every year. My boat house was up off the lake by about 5 feet up and 7 or 8 feet in towards shore. Nobody would give me a permit to repair it so I would on the weekends sneak down and be creative as heck about dealing with whatever damage the winter had caused.. I wasn't even on the main lake!
About the only boat houses that stand a chance at all are those in little tiny back bays and coves where there isn't much room for the ice to gain momentum.. Then if you build uit like a bomb shelter and massively overbuild it it stands a chance..
Frenchy, use Google Earth and look down at the lakes near where I live. Try Saranac Lake, Upper St. Regis Lake, and Lake Placid, all in upstate NY. You'll see hundreds and hundreds of boathouses.
Many of them are 100 years old, and older.
Gene Davis,
I love boat houses.. I've seen some of them up in the fingerlakes region of upstate New York and in Mass. There's even a book about them on a lake in Canada.. I fought like the devil to keep mine and it's still there in spite of all the interferance by various government branches..
On my lake if you have one grandfathered in as mine was, you need a maintinace permit to keep it.. that doesn't let you maintian it rather just gives you permission to keep it. A neighbor a few houses up had one and as a condition to letting him build a new house they forced him to tear down the boat house..
I know the pressure from government agency's on Lake Tahoe to remove the few that remain there. I was going to buy a tear down there but once I found out they would require boat house removal I refused to proceed.
One clever guy on my lake built a boat house on floats and licensed it as a boat.. However eventually they forced him to remove it..