Bowing to pressure because of the moribund economy our Provincial Government is contemplating increasing the limit for wood frame construction to 6 or even 8 storeys. Discuss.
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I don't get it.
I'm in south Florida, the heart of the hurricane zone. For the last several years we've had a rash of what are referred to as Extended Stay Hotels going up at every interstate interchange. I'm talking about 12 or 15 of them. Some have started out as CMUs for the first 2 or 3 floors switching to wood or in some cases metal frames from there up to the 6th floor. Several have been wood framed all the way up and at least one was metal framed all the way. The thing that's strange to me is that down here so many clips, straps, hangers, tie-downs and bolts have to go into a wood frame as to make it practically metal by the time they're done anyway.
We only get 2 storys here, the third with a variance.
What s thre current rule now?
But going to 8?!! on a wood frame ?!!!! wouldn't wanna be a firefighter for that!
Right now it's three storeys, or four if you play games with grade at the basement. I have done several large condos at four and effectively they ended up being steel frame with wood infill to deal with differential settlement because of the concrete block elevator shafts and fire walls. Just trying to dimension the plans was a nightmare. At eight storeys you could be looking at 4" shrinkage. I can't imagine how you detail for brick veneer or a hundred other things.
Some more thoughts: can't imagine much cost benefit for a 6-8 story building in wood structure vs. steel. Elevator cores and rated stairs would need to be accomodated. The kind of contractors working on such buildings will be more familiar with steel studs than wood. There'd be limits on cladding materials more associated with bigger buildings (i.e., stone, masonry panels, anything hung from the frame). Also limits on larger spans. Engineers and fire marshals would hate it. And the higher you go, wind becomes more of an issue than gravity.
Maybe in a scenario where units are premanufactured and stacked, this might make sense. Otherwise, it sounds like a goofy idea that somehow managed to see the light of day.
Of course it also depends on what you mean by "wood frame."
If you are talking engineered timbers with heavy metal connectors there are a number of advantages over wood or concrete for a building of that height. The Japanese are going to start building 10 story wood frame office buildings like in downtown Tokyo -- which is fire, earthquake, and typhoon prone.
We only get 2 storys here, the third with a variance.
Do you know what's usually required to get a variance?
I'm planning a three story home in rural NYS and would like to frame it all in 2X6 or even 2X8, using the Mooney Wall concept.
To get the NYS variance for the 3rd floor, normally we have to have a fire sprinkler system and 2 forms of egress.
Where in NY is your property?
If you want positive answers, I have dealt with Bob Smith in the Kingston office, who has been very helpfull.
http://www.dos.state.ny.us/CODE/reg_off_reg.htm
Edited 4/5/2009 12:05 pm ET by jayzog
Orange county. Thanks for the info and the link.
Whaddaya mean, two forms of egress? Per floor, per room?
How about a sign, "In case of fire, throw any large object against the window to break glass. Then, yelling 'Geronimo', jump".
What happens with the code if the first floor of three is masonry?
I don't much care for the idea of installing a sprinkler system, for several reasons. Do they still require black pipe for them? Or is there something easier to work with now? On rural homes with wells, do they require a large storage tank and a dedicated pump for the system?
2 forms of egress from the 3rd floor, 1 being the stairs, 2 can be another separate set of stairs, or a window that you could jump out of less than specific drop(don't remember, but I think it was 14') to a flat landing, such as a flat roof or deck. I have heard that sometimes they have allowed permantly installed escape ladders (chain type you throw out the window) as the 2nd form. I believe the thinking behind the code is that you can do the geronimo thing from the 2nd floor safley but not the 3rd, so 1st floor construction wouldn't matter.
The last sprinkler system I did for 1 of these was a 300 gallon tank with the firepump & controls attached to it, it came as all one unit. The piping was all done in copper, not sure but I think they are starting to allow pex for sprinklers now also.
If you are not in Westchestor co., you will be fine.
All building inspectors in Westchester are employed by their town or city, not the county, they all say this is state code and you need a state variance for any living space on the 3rd floor. I would don't think that the state has different requirements for different countys , of course enforcement may differ.
Yep, I belive its not the county its where they go by IRC 2006, which is everywhere in the state. Im in Jefferson county, NY and 3rd floor requries a sprinkler system.
Ask them for the reference. It changed, last I knew.
I know that we can now build 3 story apartments, so I guess if you are following same codes you should be able to also. This changed in recent past, I want to say last 2 yrs.
OK, the last time I dealt with the issue was in 06, so maybe things have changed, thats why I linked the state code dudes to HVC.
I live a stong 8 iron away from the CT border, been doing the 3rd floor there for years, maybe NY rules are the same now.
I think we adopted the last code change finally, and we are still one code book behing!
FWIW, the three story home I'm talking about will be built on a slope with each story connected to the ground by decks or other means.
I'm glad to hear that the old codes have changed to allow wood framing for three stories in NYS. I've been living in Golly-4-knee-ya but "I'll be back" this year.
I thought that one of your stories was a walkout basement?
Depends on how I do the finished grade. I may cut a steeper slope and use the fill to make a larger, terraced lawn. That's what I'd prefer to do but it needs more on-site investigation. It'll be near the top of my list, when I get back there this summer.
If it is a walk out, it wouldn't be a problem. It is considered a 2 story, at least around here.
I an working on an extended care facility that is 4 stories wood frame which is quite common here.
Wow, them's some TALL wood frames!
~ Ted W ~
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Edited 4/12/2009 11:16 pm by Ted W.
Eight storeys of wood frame ... wow
you could build it like an old grain elevator - solid walls of flat stacked 2x6 ;)
j
I believe here, if you go over 3, it has to have a steel frame. We are in a 100MPH wind zone so not really extreme conditions.
If they do start doing 8 stories wood frame, best buy stock in Simpson-Strongtie.
There are timber railroad trestles over 100-foot high. So it is structurally possible.
From an engineering standpoint; It wouldn't be difficult to design specialized glu-lam, and micro-lam timbers specifically for such installations. A specialized type that comes quickly to mind would be a micro-lam with carbon fiber reinforcement at the outer layers.
I'm not sure design of tall structure with timber framing would be cost effective in most situations though.