What type of roof contruction is this and can we vault it?
What type of roof construction is this? We're considering vaulting the ceiling to the cross member, but before I call in a SE I need as sanity check to see if this is even feasible. Thanks. Sketch and pictures below
Can it be done? Yes. But there's some engineering work that would need to be done first.
Those 2 X 6's are what's keeping the roof from spreading from it's own weight and the snow load.
What I've done in the past is build exposed boxed in beams to keep the rafters from spreading.
Your also going to have to deal with adding shims to the rafters to build them out enough to fit foam baffles and the needed insulation, and adding a ridge vent.
If you do not vault it you need to add insulation. It looks like you have at most 3 inches. In PA your heating must be huge.
Your area needs an R49 to 60.
You do know that with a that type ceiling there's going to be a lot of wasted heat stuck up near the ceiling.
There a nice look just not very practical.
Your going to have to at least add some celing fans.
per Section 802.3.1 of the 2009 International Residential Code (basis for most local or state building codes, your code may differ):
R802.3.1 Ceiling joist and rafter connections. Ceiling joists and rafters shall be nailed to each other in accordance with Table R802.5.1(9), and the rafter shall be nailed to the top wall plate in accordance with Table R602.3(1). Ceiling joists shall be continuous or securely joined in accordance with Table R802.5.1(9) where they meet over interior partitions and are nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters.
Where ceiling joists are not connected to the rafters at the top wall plate, joists connected higher in the attic shall be installed as rafter ties, or rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters, rafter ties shall be installed. Rafter ties shall be a minimum of 2-inch by 4-inch (51 mm by 102 mm) (nominal), installed in accordance with the connection requirements in Table R802.5.1(9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practice.
Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic space in accordance with Table R602.3(1).
Collar ties shall be a minimum of 1-inch by 4-inch (25 mm by 102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center.
you could install rafter ties that would prevent the rafter thrust from pushing out the tops of the walls, or you could install a structural ridge beam, it depends if you would want the rafter ties showing in the vaulted ceiling area or not. if not, a beam would be the way to go.
you can find the 2009 IRC at the following link http://publicecodes.cyberregs.com/ic...2009/index.htm
my humble thoughts ... :thumbsup:
Thanks for all the replies, upon reflection I don't think we're going to vault the ceiling unless the engineer really convinces me otherwise. insulation issue, reaching the R60 mark, I still need to replace the shingles and I don't want to spray foam and then have to deal with that mess. yeah it would look nice but the long term heating and cooling is a turn off. So we're just going to remove a bearing wall and that is what we're going to have the engineer draw up and stamp for us.
had some friends visit us http://www.diychatroom.com/members/g...5-dsc-5603.jpg
And then garlicbreath goes over to landscaping and asks how to keep deer from eating up all his new plantings.:wink: Ah,well, some things are worth a few nibbled plants.:)
You are probably right not to to eliminate the ceiling to get a vaulted look. The engineering may sound simple according to the minimum standard codes. Few good engineers will not be so minimal in the design because of the liability for any problems that could be associated with the roof revising. - It is not a strength problem, but a long tern performance situation that is usually not worth the minimal fee.
I our area, some suburbs hire professional hunters to control the herds of deer. The biggest problem we have is geese and turkeys.
Feral hogs here, coming right into heavily built up areas along river bottoms, expensive, unsuccessful eradication program going on. And folks move into developments with beeyootyful creekside view, thrilled that there are beavers in creek. Comes first spring or fall comes the panic, "Beavers are eating our trees!" Authorities used to trap and remove, now most say, they were here 1st, protect your trees. Cause the beaver just came back or new ones moved in. Oh ho. I just now had visitor of my own, sittin here on deck, I heard a continuous rustling coming nearer thru leaves that cover back easement due to drought. Not usual squirell or bird noise. looked over, big red eared slider. Reckon he's comin from shrinking pond about 1/4 mile away, headed towards another about 1/2 mile, good luck, turtle, that one's shrinkin too. Odd that should appear whilst talkin of visitors, coincedence? I think so. haven't heard of hogs, beaver, or turtles gettin into attics, which reminds me.
garlic, you asked what type construction you got, its just a common gable roof with collar beams ( aka collar ties). How old your home? Not required for many years now, except in special circumstances, and then need to be designed for the circumstance. Folks still put them in, mostly cause they always have. Used to be needed in older, weaker, balloon or western framing. Newer framing require better rafters and spacing with proper rafter ties, which can be the ceiling joists. ( See GB's ( aka Code Copper):wink: post.) Note; the joist/tie has to be continuous from outer wall to wall, and it looks like some of yours aren't, but easily remedied.
The collar is meant to keep rafters from pushing walls out, but in flimsier frame, long or shallow pitch rafters, which seems you have, rafters would sag or bow down. Builders would use collar in attempt to prevent that, which they don't do so well, especially since they are usually only on every 4th rafter pair and usually a 1X4 nailed on. You can take them out, but since you wisely decided against cathedral ceiling, no need. Unless you need some 1x4's for something. Probably nice and attic kiln dried, and hard as a rock. Man old rafters can be hard. And that concludes today's lesson in roof framing. Test tomorrow.
Wait, can it be? Yes, rustling again, turtles coming back the other way. I know i reply over lengthily and type one finger slow, but not enuff time to get to other pond. Mebbee met another turtle comin from there. "Turn back, brother, the water hole's dryin, and the catfish are headed cross country. We're all dooomed, brother doomed!" Neighbors cats have spotted it, can't seem to make out exactly what it is, seem to have decided its somethin to leave alone but keep wary eye on.
|All times are GMT -5. The time now is 05:45 AM.|
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.