Second floor addition over first floor with cathedral ceilings?
Second floor addition over first floor with cathedral ceilings?
(OP)
I have a rancher style house with cathedral ceilings and I want to add a second floor addition over them (keeping the cathedral ceilings as they are.) Any thoughts? Can I build a small section of framing onto the existing framing of the exterior walls high enough to get level with the top of the existing roof and then add floor joists and framing for the second floor above that (this is assuming that I can shore up the support beams in the existing ceiling well enough to support the second floor joists)?
Any thoughts on this would be greatly appreciated.
Bodvar
Any thoughts on this would be greatly appreciated.
Bodvar






RE: Second floor addition over first floor with cathedral ceilings?
RE: Second floor addition over first floor with cathedral ceilings?
RE: Second floor addition over first floor with cathedral ceilings?
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Second floor addition over first floor with cathedral ceilings?
RE: Second floor addition over first floor with cathedral ceilings?
Perhaps I should be asking only for comments from anyone who's ever been involved in a similar scenario - what did you do? But I don't want to limit my question that way. I'd like to hear from anyone that has an innovative idea.
Anyway, enough said - looking forward to hearing what you guys might come up with (hopefully a little more creative than being directed to consult with an engineer.) If not - that's fine too.
RE: Second floor addition over first floor with cathedral ceilings?
Install ledgers
Install clear span floor joists - might be LVLs or TJIs
Install SOB or other approved sheathing.
Don't touch exsting celing.
Before you begin, check that footins can carry additional load.
That is the basics....
RE: Second floor addition over first floor with cathedral ceilings?
A thought here... The loading for floor is 40 live plus 10 to 20 psf dead, depending on whether or not you have gypcrete on your floors. Probably not. So figure a normal 50 psf loading for your new floor.
The dead load of the existing roof structure is probably 12 to 15 psf (unless you have a tile roof, with a live load of 20 psf. You ccan get extra capacity of 3 to 5 psf in the existging roof structure by removing your existing roofing material. If you are in a region that has snow load too, if that design roof snotw load is equal to or greater than 40 psf, you MIGHT be able to post down to the existing roof scissors trusses, but that would be the call of the structural engineer you ARE going to consult.
The design would still be subject to the other limitations mentioned above.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Second floor addition over first floor with cathedral ceilings?
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Second floor addition over first floor with cathedral ceilings?
He said he has a ridge beam and rafters, not scissor trusses.
RE: Second floor addition over first floor with cathedral ceilings?
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Second floor addition over first floor with cathedral ceilings?
Intuitively seems to me that taking the existing roofing material off of the parts of the roof that get covered is a good idea too - wood likes to breath. And as you say it will probably save some weight as well (~2.0 psf for asphalt dead load probably makes up for the second level sub-flooring in those areas.)
RE: Second floor addition over first floor with cathedral ceilings?