My question my be stupid, but I am new to all this. My parents own a house on a lake and they are getting up there in age and will need someone to help them in the next few years but we need to add on in order to have enough room. The only way we could go is up. It has a walk out basement so on the lake side it will look like 3 storys but on the road side it would look like a 2 story. My first question is, and if this doesn't make sense let me know, The original house is smaller that what the buildable space was so they could put a monstor deck (lake side) on the full length of the house, what is the span in which we can overhang the 2nd/3rd level over the deck without supports coming down.
The answer to your question depends on how you build the second-story addition, and to some degree the direction of the ceiling joists in the existing house. With conventional wood framing, such as 2x8s or 2x10s or even 2x12s, the normal cantilever allowed is two feet. You may have to use engineered composite joists to clear-span the house to avoid having to replace the center girder in the basement, if there is one, or because the footings under the columns in the basement are too small to take additional load. Cantilevering those joists takes a little bit of engineering. The manufacturer will place a limit on the amount of cantilever unless specially engineered.
With some special structural design, this cantilever can be increased, and basically the more money you spend on it, the further you'll be able to cantilever, using engineered wood or steel. There is probably a practical limit of between four and six feet, and that might require tearing up some of the existing house to accomplish. Beyond that, I'd have to see the house to be more specific. You will need an architect who knows what he or she is doing, or a structural engineer, to accomplish a large cantilever.
Architect (NY) and Home Designer (PA)
Posts: 2451 | Location: Tobyhanna, PA | Registered: 24 October 2005
Thank You Richard. Do you know of anyone in the Tomahawk, WI area. It would increase the living space by 640 sq feet so it may be worth checking into, I guess it won't hurt anyways then we will know for sure.
Funny you should ask...the house isn't on Road Lake, by any chance, is it? I do know someone in Tomahawk, but she's not an architect or engineer. Small world.
Architect (NY) and Home Designer (PA)
Posts: 2451 | Location: Tobyhanna, PA | Registered: 24 October 2005
We've did a few of these and one thing you should consider in the design stage is to have the stairway running parallel to the floor trusses of the new addition. This will help in eliminating a need for interior bearing posts. I've had to do these on occasion, trust me they aren't fun or cheap.
General Contractor/Home Builder
Posts: 288 | Location: Minnesota | Registered: 15 January 2007
Originally posted by Richard Hetzel: Funny you should ask...the house isn't on Road Lake, by any chance, is it? I do know someone in Tomahawk, but she's not an architect or engineer. Small world.
No it is not on Road Lake, we are in Harrison Hills. But yes small world isn't it. Thanks
Originally posted by JayinMinnesota: We've did a few of these and one thing you should consider in the design stage is to have the stairway running parallel to the floor trusses of the new addition. This will help in eliminating a need for interior bearing posts. I've had to do these on occasion, trust me they aren't fun or cheap.
Thank You I am learning alot from this site. Thanks to everyone.
