Question for New England Builders
Dan_Morrison
| Posted in Construction Techniques on
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Why do you strap the ceilings with 1×3 or 1×4’s? Everytime I ask someone I get a different answer. I’ve not seen it done anywhere else in the country but here in New England.
When in Rome,
Dan
Replies
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Dan--
Strapping can be shimmed level for joists that don't line up well with their neighbor.
Double runs around edges of rooms make it easier to nail up crown.
Replaces bridging's purpose of keeping joists from rolling under load.
2 1/2" is an easier target than 1 1/2" when installing sheetrock, especially at but joints.
Interrupts sound transfer somewhat by creating an air space above the sheetrock.
Provides an easy place to run low-voltage (and sometimes full-voltage) wires.
Sometimes partition walls are framed up after ceilings are strapped--just nail the wall to the strapping.
Last but not least--THAT'S THE WAY IT'S ALWAYS BEEN DONE HERE!
Mike
PS How's the work going up there?
*All good reasons but the one i like best is barrier against sound transfer.Historicly it comes from when they built with log beams hand hewn that needed leveling, and plaster with hand split lathe.
*Thanks."That's just the way we do it here" is what I've heard most. One guy told me it makes the interior partition walls easier to anchor at the top, which made sense at first until I realized that you then needed to cut every stud 3/4" shorter than those on the exterior walls (which are usually pre-cut 92-5/8" wherever I've framed new houses) at which point it seemed that it wasn't such a time saver after all.I like to eliminate bridging because I think it results in floor squeaks. I like the sound transfer idea too.Easier for the sheet rockers... Ok, I'll buy that. Don't want to get those guys mad.And I have seen the Romex run between then, but that makes me nervous. I just feel safer knowing it's buried in the floor joists where no errant screws or nails will hit it.Backing for crown. Yes, but you still need to run blocking perpendicular to the strapping , do you not?It appears to be a little more work and material with a lot of benefits. I wonder why other folks don't do it?I did it once in an historic restoration where the ceiling (floor above) needed beefing up. (I mean of course that I strapped the ceiling -- I also did it but that's none of your business) We were on a limited budget and so couldn't afford to re-frame. What we decided to do is hang a TJI joist every two or three feet (I can't remember which) by adding blocking to the walls and using joist hangers, then we strapped the underside. This was in Montana and boy were those sheet rockers happy to see that -- "We could hang this room drunk" I believe was the quote... 3-1/2" target is quite a bit like the side of a barn.Mike, how's work going you ask...Work is going fine. We're busy. I'm in the middle of three additions right now, each one gets stalled for a different reason, so we start with another one. Now it looks as if they'll all hit the fan now at the same time. Have you had any luck on your job search? If you're still looking why don't you send me a resume and I'll forward it to my boss. Maine State Builders is the company. I'm not sure whether he wants another guy, but I suspect we could really use someone who can carry the ball if we give him a hand off. (Pardon the football-speak, it's that damned Super Bowl fever). We just hired three guys. One is a kid. One is a pretty good wood worker with little production experience and the last is a production guy who needs coaching to get the level of quality I'm looking for. But I think we could use another lead.Call me either Friday after work, maybe Saturday night, Sunday around noon, or Monday after work and I'll fill you in on the details of what we've got to offer.Oh yeah, Thanks for the historical perspective piffin, that makes all the sense in the world and explains why no-one else "always has done it that way". Where are you located?Dan
*Islesboro, ME
*Islesboro. No kidding? I grew up in Northport. Just accross the bay at Temple Heights. Moored our boat in Bayside and used to sail over to Turtle Head Cove for picknicks all the time.Small world.
*Island Institue has a potion of Turtle Head set aside for public use now - kind of a conservation piece.Long row on a windy day.
*One more reason is that the strapping helps support the insulation. I've seen a room done without strapping and you could see the sheetrock sagging.
*I don't see how strapping helps dampen noise transmission. And why would it be any easier to frame interior partitions to a strapped ceiling? Come to think of it, most modern lumber is pretty danged consistant, too. TJIs sure as heck are. Do you guys strap TJI ceilings, too?
*Yes, that way you don't need blocking.It slows sound transmission because it is solids that carry sound waves through. Your point of contact is between SR and strapping on the bottom, between plywood and joists above, with only the small four square inches every 16"OC that has full contact. Also direction is in opposition to that of joists so sound waves are baffled and broken up like in an auto muffler.I agree that it doesn't make much difference for fastening interior walls. That one is six of one and half dozen of the other.
*Thanks, Piffin. I just assumed sound traveled through the space, not the solids. That does make sense now. Are you saying you block all your joist spans?
*Not through space but it will through air - just not as well as through solids. Also, Mass will absorb a certain amt of sound so if you have a poured thermal radiant floor, it will do a lot too.What happens is sound above is vibrating the solids of the plywood flooring/subfloring. Carpet or mass absorbs some of that sound. What ever is left is energy that becomes vibrations in the air space and is transfered once again to the SR cieling below. By having the cieling fastened directly to the joists, you give it a shortcut so more gets through.There's a story that is a good example of this. In WW11 a ship was destroyed by bombing attacks. A sailor was swimming away as it sunk. He had to swim much of the way underwater because of burning oil slicks. His testimony after being rescued was that he heard a large explosion while underwater just before the ship sank. He surfaced for air immediately and heard another large explosion. Other witnesses only heard and saw one so investigators looked into the possibility that mines were involved. The conclusion of the matter was that the discrepancies were due to the fact that he heard the same explosion twice, the sound having traveled faster in the water, since it is denser than air.No, I don't block all my joist spaces but even when it is notn required, the strapping stiffens things up or adds for a marginal engineering design. My customers don't like to see the wine glasses jiggle on the dining room table when the servers hoover around.
*Crazy Legs, Strapping on the ceiling does make it easier for interior partitions, especially when you have a wall that is parallel to the floor joists. Walls that are perpendicular to the joists get their own nailer, typically 2 pieces of strapping acting as a nailer for the sheetrock. Dan, The interior studs typically need to be about 5/8" to 3/4" LONGER than the exterior studs. The exterior walls get a double top plate and the interior partitions get a single top plate. I lot of builders buy pre-cuts for the entire house. They have the framer place a piece of strapping on top of the wall to make up the extra height. This way you don't need 2 different length studs. 92 5/8" for the whole house. Example; EXTERIOR WALLS. 92 5/8" stud + 4 1/2" for three plates = 97 1/8" INTERIOR PARTITIONS. 92 5/8" STUD + 3" for two plates + 3/4" strapping on the ceiling + 3/4" strapping on the top of the wall = 97 1/8"Usually 3 plates measures a little over 4 1/2" and the strapping measures a little under 3/4" so there is enough tolerance to get the partitions in fairly easily. Wires are usually stapled to the side of the joist or the bottom of the joist. There shouldn't be any wires resting on the strapping where a sheetrock screw could hit it.I have framed a garage or two without strapping the ceiling but never a house in my twenty something years framing.