A lot of you guys said that my cabin spanned across water was a bad idea. I reworked the design a bit so I could still fish off a (steel enforced) deck. Any engineers/architects lurking right now?
Not an engineer but maybe this would be more feasible spanning a river than hovering over a lake? (though maybe I’m just hoping you’ll do a drawing of that)
Edit: just looked through your post history and my prayers were answered!
FrozenChihuahuasays
Not an architect, just someone that appreciates some great ink work. Nice sketch man, really like your style
bravoitalianosays
Not an engineer, but this design is dependent upon the right soil, or actually Bedrock for what you want to do. Anything submerged into a water table will need to be properly leveraged against anything solid that won’t shift. If you have the wrong setup, it’ll just sink. I imagine that based on major bridges, if you want to do this and have enough money, anything is possible. Good luck!
talldeansays
This looks like a bad idea that could be damn good, albeit it’s gonna cost.
You’d want a second weight farther to the right as a counterbalance for the cabin; the current weight would be the pivot of the fulcrum, and with two large chunks of foundation, you’d need way less foundation for that to stand up longer term. In both cases, you’d need to get below the water table with the supports, so it might also make sense to do geothermal heat pumps while you’re digging.
Take a look at Frank Lloyd Wright’s "Fallingwater" in Western Pennsylvania. They did something similar, and it took… a lot… to save the house as a historic landmark.
jarniansahsays
Unless you’re placing that foundation in bedrock, anything else would be risky.
I’m assuming you’re in a region which gets cold winters and snowfall, your water level on the river is never going to stay constant. It’ll rise during the spring season and you can erode the river embankments that you’re relying on for stability. So you’d need to reinforce your banks using maybe gabian baskets.
Also during the increase of flow, your ground water table will increase around the areas of the river, so unless you’re drilling way deep down (which I don’t think you are cause it’s a cabin) you’re at risk of the soil sliding into the river because soil does not hold in tension at all. Once the soil near the foundation gives way, your cabin will simply plop to one side.
You need much more support (assuming you’re drilling in the bedrock), your cabin is basically cantilevered beam.
I’m in my final sem of Civil Eng so not a practicing professional, but I’d stand by my comments
rasm0208says
Setbacks wouldn’t allow this. If you have a site already check with the city planning department for the setback needed from a body of water. Where I live it’s 75′. The amount of steel and ground anchoring needed for that design would cost a fortune as well.
DaftLemonsays
Incredible satisfying sketch
Osuamsays
I’m an engineer, very cool design but I see a lot of headaches in the future when it comes time to build. From what I can tell, your cabin is resting on a platform and your platform is only supported on one end, some people would call this a "cantilever" situation and it places enormous stress on the members connecting the column to your platform. On top of this you’ll have to consult a licensed professional structural engineer regarding legal viability – I have a few concerns by glancing at your drawing but my biggest concern is lateral stability in an earthquake event. Along with this, if your interested in fishing the lake I’d assume there are some environmental restrictions in place for construction in that area, bring this up to your engineer. Lastly, you MUST hire a Geotechnical engineer (or have your lead engineer hire one) to submit a soil survey. Since you’re next to a lake I’d guess the soil is fully saturated with water which is bad for foundations, hopefully there’s some bedrock in the area where you would like to place your columns.
Lastly, consider logistics, you will need some heavy machinery and heavy building materials to make this happen, is your choice area near a highway? Are there paved roads leading to the site? Logistics is extremely important in construction, so don’t brush this question off.
In not saying all this to discourage you, you have a super cool concept and I don’t think you’ll have a problem finding a structural engineering firm (we love problems like this) willing to tackle the problem, but you are looking at an extremely work intensive project (lots of $$$) .
filomeosays
First I want to applaud the inkwork, really gets the emotion right. As an architect, I would say the balance is off, both architecturally and structurally (as these comments all say). A good rule of thumb is 3:1 backspan for cantilevers (like your deck). You can break this rule with money, calculations, or both; but starting with 3:1 will likely help in more ways than one.
PNWAlex125 says
Not an engineer but maybe this would be more feasible spanning a river than hovering over a lake? (though maybe I’m just hoping you’ll do a drawing of that)
Edit: just looked through your post history and my prayers were answered!
FrozenChihuahua says
Not an architect, just someone that appreciates some great ink work. Nice sketch man, really like your style
bravoitaliano says
Not an engineer, but this design is dependent upon the right soil, or actually Bedrock for what you want to do. Anything submerged into a water table will need to be properly leveraged against anything solid that won’t shift. If you have the wrong setup, it’ll just sink. I imagine that based on major bridges, if you want to do this and have enough money, anything is possible. Good luck!
talldean says
This looks like a bad idea that could be damn good, albeit it’s gonna cost.
You’d want a second weight farther to the right as a counterbalance for the cabin; the current weight would be the pivot of the fulcrum, and with two large chunks of foundation, you’d need way less foundation for that to stand up longer term. In both cases, you’d need to get below the water table with the supports, so it might also make sense to do geothermal heat pumps while you’re digging.
Take a look at Frank Lloyd Wright’s "Fallingwater" in Western Pennsylvania. They did something similar, and it took… a lot… to save the house as a historic landmark.
jarniansah says
Unless you’re placing that foundation in bedrock, anything else would be risky.
I’m assuming you’re in a region which gets cold winters and snowfall, your water level on the river is never going to stay constant. It’ll rise during the spring season and you can erode the river embankments that you’re relying on for stability. So you’d need to reinforce your banks using maybe gabian baskets.
Also during the increase of flow, your ground water table will increase around the areas of the river, so unless you’re drilling way deep down (which I don’t think you are cause it’s a cabin) you’re at risk of the soil sliding into the river because soil does not hold in tension at all. Once the soil near the foundation gives way, your cabin will simply plop to one side.
You need much more support (assuming you’re drilling in the bedrock), your cabin is basically cantilevered beam.
I’m in my final sem of Civil Eng so not a practicing professional, but I’d stand by my comments
rasm0208 says
Setbacks wouldn’t allow this. If you have a site already check with the city planning department for the setback needed from a body of water. Where I live it’s 75′. The amount of steel and ground anchoring needed for that design would cost a fortune as well.
DaftLemon says
Incredible satisfying sketch
Osuam says
I’m an engineer, very cool design but I see a lot of headaches in the future when it comes time to build. From what I can tell, your cabin is resting on a platform and your platform is only supported on one end, some people would call this a "cantilever" situation and it places enormous stress on the members connecting the column to your platform. On top of this you’ll have to consult a licensed professional structural engineer regarding legal viability – I have a few concerns by glancing at your drawing but my biggest concern is lateral stability in an earthquake event. Along with this, if your interested in fishing the lake I’d assume there are some environmental restrictions in place for construction in that area, bring this up to your engineer. Lastly, you MUST hire a Geotechnical engineer (or have your lead engineer hire one) to submit a soil survey. Since you’re next to a lake I’d guess the soil is fully saturated with water which is bad for foundations, hopefully there’s some bedrock in the area where you would like to place your columns.
Lastly, consider logistics, you will need some heavy machinery and heavy building materials to make this happen, is your choice area near a highway? Are there paved roads leading to the site? Logistics is extremely important in construction, so don’t brush this question off.
In not saying all this to discourage you, you have a super cool concept and I don’t think you’ll have a problem finding a structural engineering firm (we love problems like this) willing to tackle the problem, but you are looking at an extremely work intensive project (lots of $$$) .
filomeo says
First I want to applaud the inkwork, really gets the emotion right. As an architect, I would say the balance is off, both architecturally and structurally (as these comments all say). A good rule of thumb is 3:1 backspan for cantilevers (like your deck). You can break this rule with money, calculations, or both; but starting with 3:1 will likely help in more ways than one.