Building advice for the Ultimate Boat House.

[inveresk]

Eddie, I share the view of some of the other posters, that a floating boat house might be the answer. Firstly, if the level of the lake rises and falls, then the boat house will follow. The advantage of this is that the relationship of the boathouse to the surface of the water is always the same so should make getting into and out of a boat simpler. if the boathouse is on piers, then the means of accessing a boat from it needs to be variable to take account of rises or falls in the water level - i.e. either a ladder or steps. Not so comfortable for the eldery or infirm. There may be no intention to design for this type of user but it might be a consideration.

I had one project under my direction where we had to demolish an existing jetty, about 100 years old, on the banks of the river Tay. The wooden piles for the pier came out of the silt river bed pretty clean and easy. They were about 15 - 16 inches in diameter, about 30 feet long and even after a century in the river were really solid apart from the outer 1/2" or so which was soft.

The wood was Greenheart, a tropical hardwood, and although I appreciate that calibre of wood isn't available, perhaps at any cost, in this day and age, it does illustrate that timber piers can last if the species of wood is the correct one.

If a floating boathouse or if timber piers aren't an option, then how about steel pile casings sunk into the lake bed then filled with concrete once they're in place? It should be simple enough to design them such that if the steel casings corrode, the concrete is man enough to do the job on its own.

There's a method for filling casings - you have to make sure the concrete pump is sent to the bottom before you start pumping and that you pull it up at the right rate to fully fill the casing. If the mouth of the pump is too high initially, or if you pull it up at too fast a rate while you're pumping, you can get air pockets (which you seriously don't want). I've seen concrete pumps with two meters, a pump volume meter and a rate of withdrawal meter (sounds like a birth control method!) which allows the pump rate to be coordinated with the withdrawal rate to avoid air pockets. We used this method on one job I designed where we had to auger pile through mudstone. We couldn't use driven piles because of the risk of vibration damage to adjacent buildings.

p.s. sounds like a really nice project. Hope the progress photographs will follow in the course of time.

 

[EddieWalker]

I was wondering how you get the concrete into a pier with out having air pockets and also get the water out. It's a pretty simple solution now that you explain it.

As for floats and doing it that way, I really don't know. I've just received the deposit from the client on remodeling his exam rooms and that's my main goal right now. He's open to allot of ideas, but we never discussed floats for this. None of the other boathouses or piers have floats, so I don't know if it's a homeowners rule, a deed restriction, a lake authority rule or if everybody else just likes wooden posts.

He's dead set against wood posts. That would be the cheap and easy way to do this, and my first choice as well. Of couse, he can get anybody to do it that way, and that's not why he wants me.

I honestly don't know if we'll do this or not. It's not a big priority for him, so it could be this year, or several years from now. How much he likes the job I do on his exam rooms will also make a huge difference in wether I get this job or not. He has the money and knows it's not gonna get any cheaper. He wants a place to take his kids while they are still young. So there are all sorts of angles to this.

Thanks for the advice,
Eddie

 

[BTDT]

Eddie, if money is not an object, this is what I would do. Drill pier holes on land, design for boat storage from channel to lake, with enough concrete to offset weight of house that would be cantilevered out over lake. Above boat storage would be parking area for cars. Crude drawing, but I think you can see what I'm suggesting. Don't know how big of a house he wants, but with enough concrete on the bank, you could hang a pretty fair sized home out over the water.

 

[EddieWalker]

BTDT,

That's certainly the most unique idea I've heard. Not sure if it's what he's looking for, but I've printed out your drawing and will show it to him the next time we get together.

I'm building a small file on the different ideas that everyone has come up with that we'll discuss and determine what looks like the best approach.

Thanks,
Eddie

 

[txdon]

Eddie, I saw this on the news tonight and thought of this thread.
The Texas floods are not flooding this floating house.

MyFox Austin | Man's Floating House Plan Working So Far

 

[bones1]

Re: Building advice for the Ultimate Boat House.
Eddie, how different does he want his boathouse to be?.How much $$$ will he spend to be unique on the lake?.I propose building your pilings out of the material of choice to the correct height so as you can incorporate a computer controlled hylraulic lifting system such as in the links below, to raise or lower the boathouse with the tides or water level.The lifting platform, mounted below water level would automatically determine via sensors or data feeds the correct height to keep the house.These systems can be designed to carry the weight you come up with.He not only have the neatest boathouse on the lake but could sit in his boat or onshore and show the other Doc's how his goes up and down with a remote. Flexible utilities of course.
Hewitt Hydraulic Boat Lift
http://www.shoremaster.com/images/animated_files/vertical_lift_small.gif
http://www.tigerboatdocks.com/lift/lifth33.jpg
ShoreStation Boat Hoists, Lifts, and Dock - Lakefront Systems

 

[EddieWalker]

Thanks for the advice and suggestions. Right now, I think I've lost the bid. He's talking to a friend of his wifes who says he's done a bunch of these and knows everyone on the lake already. I told him that I can't compete with that and would respect his choice in hiring the more experienced contractor.

This was pushing my skills and knowledge, so it's not something I'm unhappy about. I like new challenges, but hate the idea of building something that isn't going to last or be in a position of not knowing what I'm doing.

I still have other jobs that he wants me to do, and one that I'm being paid to do, so it's not a bad thing. Might even be a good thing!!!

Eddie

 

[hitekcountry]

I have an out of the box solution that I think satisfies all your customers needs and wants and makes it a project that takes advantage of all your experience and skills.

You have experience in building dams, pumping water, and excavating, pouring cement just not under water.

What I propose is to build a temporary dam out into the water to expose the building site and allow it to dry out then to excavate down (you’ll need engineering calculations for per sqft req.) as needed and pour a large solid slab which is essentially one large cookie to support all your concrete columns. I would want a few walls for sheer. Then on top of the columns and walls the rest is standard construction.

After your support structure is built you excavate to remove the dam and to dredge the area to the depth desired.

See sketch

 

[jinman]

IWhat I propose is to build a temporary dam out into the water to expose the building site and allow it to dry out then to excavate down (you’ll need engineering calculations for per sqft req.) as needed and pour a large solid slab which is essentially one large cookie to support all your concrete columns. I would want a few walls for sheer. Then on top of the columns and walls the rest is standard construction.

After your support structure is built you excavate to remove the dam and to dredge the area to the depth desired.

See sketch

Yeah, as soon as I read that Eddie's client would not have cost limitations, I thought a cofferdam might be a great solution and allow building anyway you'd want. The problem is building a cofferdam in place or hauling it in. Of course, I'm just brainstorming...