I just got done with the latest issue of FHB. I thought the article on efficient framing was interesting. Some ideas made sense but others were a little hard to accept. The single top plate seems a little flimsy even with the shear panels. The author says we’ve been overbuilding along. I rather overbuild than underbuild and that’s what this looks like to me. What do you guys think?
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There have been other threads here about this. Try some searches.
It is all about using less wood in your exterior walls so you can get better thermal performance with more insulation. To my way of thinking, it is a valid way to frame, but it all must start in the early planning of the job.
Modular layout is a big key. That means aligning windows and doors to the 24-inch module, doing wall lengths accordingly, and most importantly, stacking framing so that floor joists and roof rafters or trusses bear on those modular lines.
A USG or Simpson joiner plate is used to join the single top plates, which of course have their ends right above a stud. With stacked framing, you aren't losing any measurable structural integrity by single-plating.
The only reason that I know of for a double top plate is so that you don't have the burden of making sure that there is a stud directly under every joist and/or rafter.
Andrew
To my knowledge, there ought to be a stud below each joist/rafter regardless of the number of top plates.
Top plates allow for the interlocking of walls.
J. D. Reynolds
Home Improvements
If you have a double top plate, you do not need to stack out your framing such that rafters or joists land on top of a stud. The double top plate and sheathing acting together will distribute the load from each rafter or joist bearing on it to the nearest studs below. That extra top plate can offer a lot of layout flexibility which can also save a lot of lumber.
You're right that if you do stack out your framing AND use a double top plate, you'll end up with yet stronger construction. But at what cost? It not only costs you the extra wood, but it costs the owner forever onward in energy consumption from that extra thermal bridge from the inside to the outside.
How can layout flexibility save more lumber than planning and executing the job using the "modern framing" methods being discussed?
These methods are possible, however I'm not sure how realistic, If you were to get rid of the one top plated how would you connect long sections of wall together and stand them. Or when you have sections of floor on 12 o.c would you then have to remember to make those studs on 12 o.c or would you trim an inch and a half off of all your studs and double plate those sections only. How much time are you willing to spend to make all of these things jive. I agree 100% with being more efficent. I've always changed my layouts to lose a stud or save plywood cuts, I don't put cripples against the jack studs under window sills because there is no need for it to be there. I think the two foot center wood work in most cases and burn you in others. I like the idea of a light wall to lift and one top plate making a wall easy to straigten. The best thing about the article in my opinion was the use of drywall clips instead of lumber. In the future if we were able to use a product similar to wood with more resistance to rot and with better insulating properties that would be the thing to focus on. In the mean time we could all just be a little more concious of how we design these houses and buildings and how we lay them out.
You're right, these methods give optimal use of materials for new construction where dimensions are (almost) entirely at the discretion of the designer- presuming there's no owner yet to mess with it.
If you're building an addition etc. your flexibility in terms of layout is greatly reduced, and your ability to implement some of these ideas is limited. The article gives good advice in regard to which ones give the most "bang for your buck", and I found that very helpful.
I'm pretty sure that you have to be within, either 4" or 5" of a stud if you have two floors above your framing even if you have a double topplate. So on the first story of a two story house, your joists need to be close to the studs in the wall. An inspector pointed that out to me on a walk through of a house we had subbed out.
But then again, inspectors aren't always correct :-)
Tell me about it- inspectors are in a position where you can't really argue with them without risking more marginal calls on the rest of your work.
I'm far from an expert on this, but I've seen nothing in the Ontario Building Code in relation to stacking out framing, even when you're the first floor with two more above. I have no experience with other codes. If you have a point load from a header or beam or some other interruption in the floor framing above, that would be cause for concern, but if it's just joists landing on the top plate with a rim and double top plate to help distribute the load, I doubt there's any concern about sagging.
"If you have a double top plate, you do not need to stack out your framing such that rafters or joists land on top of a stud. The double top plate and sheathing acting together will distribute the load from each rafter or joist bearing on it to the nearest studs below. That extra top plate can offer a lot of layout flexibility which can also save a lot of lumber."What flexibility in the layout do you have? If you layout your studs 16" oc whether it's an addition or new home, aren't you going to layout your joists to stack above them whether you have a single top plate or double top plate?So the only savings in lumber is the top plate. Your not going to save on any joists. What are your going to do, layout your floor joists and ceiling joists in the middle of the wall studs? What about mechanical?What size precuts do you have there? Eliminating a top plate would screw up the sheetrock around here with 92-5/8" precuts. Joe Carola
Not stacking your framing is just not allowed. It has been enforced in California for at least 25 years now. Part of being a real tradesman is taking care of the other trades. A stacked wall gives a continuous chase for plumbing and wiring all the way to the lid. It is expected by all that when you drill into a plate that you will not hit nails or hardware. It seems common sense but I get the feeling that the rest of the country has not caught up to the west coast yet. Why would anyone not stack the framing? Perhaps because of our seismic codes most homes are required to have the whole shell sheathed in plywood. If the layout was not continuous then there would be a lot more waste.
When there is no snow loads where the roof framing is 2' centers and the walls are 16" centers then you are allowed to stack on 4' centers and a double top plate is required.Mike Callahan, Lake Tahoe, Ca.
You've given good reasons to stack your framing, but it's not a code requirement here. A continuous chaseway for other trades is a bit over-sold though. You shouldn't be putting anything other than wire into exterior walls anyway unless there's no alternative, and wire's easy enough to route even if the framing doesn't stack.
The point I was making was about the value of the 2nd top plate in giving layout flexibility if you're using 24" centres on anything to save lumber or reduce heat loss, yet you're required to go with 16" centres with another building component (joists say). This is made even more important in remodelling than in new construction because the existing structure is already there and almost certainly doesn't use these techniques, so you're even less likely to get everything to stack out. And it doesn't take too many trusses or joists saved to pay for that extra bit of 2x6 to put up the 2nd plate.
I agree that 24" centres for joists is totally unappealing, but 24" centres for trusses or rafters or wall studs can represent significant savings. I wouldn't be deterred from doing this because of a fear of not having stacked framing.
Personally I'd be way more fearful of eliminating significant portions of structural sheathing to replace it with foam or other insulating non-structural sheathing than I would by increasing the stud spacing in a wall. But studs on 24" centres PLUS the elimination of significant portions of structural sheathing- that makes me a bit nervous. Properly detailed sheathing provides a very significant portion of the strength of a house, not just in bearing but in all the other directions loads can be applied during wind or seismic events. Sure, sheathing the corners and putting in a few shear panels may be structurally adequate, but I sure like a fully-sheathed Mooney wall better from both a structural and a heat loss perspective.
> You shouldn't be putting anything other than wire into exterior walls ....
A good idea in cold climates. But here in non-freezing Southern CA, it's pretty much standard to have a window over the kitchen sink.
-- J.S.
The same is desirable if not standard around here too. You just need to be more imaginative with your plumbing (and cabinet design) to route the vent for the sink without running it in the exterior wall.
My reading of the codes that address this (for example, the "One and Two Family Dwelling Code " by the International Council of Building Officials (ICBO) refer to both. That is, any description of allowing for a single top plate requires strap ties to interlock walls for lateral resistance, and also a stud directly below every joist and/or rafter
Andrew
Edited 9/26/2005 1:39 pm ET by AndrewG
I agree about interlocking walls also a double top plate sure is nice for crown installation but, if push comes to shove you can always nail to the studs. I guess it is just what you get use to.
The article on 24" oc framing definitely onto a better way of framing; however, the 24" oc floor joists seemed inadequite, and the solution of a 1 1/4" OSB subfloor detered me from the entire operation because of the excessive weight. To add the extra joists to make a 16" oc floor and use 3/4" plywood would not work because the framing must be stacked.
The claim that this design could hold up in a hurricane zone, even with the extra panels, is insane. Under driven rain, the OSB sheathing elements would soak and fly off the house like wet bread nailed to a 2X10 (see FHB "Hurricane Watch"). Installing Dow Board in the center of the wall is unintelligable and would likely result in the destruction of the house and/or death of occupants from debris flying at 80 plus mph.
It is my own belief as a carpenter that filled cynderblocks of poured concrete walls (either reinforced with steel rebard) should be the norm in non storm-surge hurricane areas. Poverty is not an excuse as to why not to go along with this design. I work with many guys from the West Indies and that is the only way they build residentially in thier countries.
Hurricane country requires special building methods. Reinforced concrete block unit walls, reinforced full perimeter bond beam at the roof line, etc., etc.
There was never a statement in the article, nor does anybody here (I believe) tout these framing methods for everywhere in our good old USA. Especially hurricane country, or seismic country, for that matter.
But fly over at 35,000 feet, from coast to coast, and you will see a whole lotta territory where these building methods will suit people just fine.
And my guess is that when events like Andrew in Homestead, and Katrina in Gulf Shores take place, sixteen inch centers, doubled top plates, heavy sheathing, and more, just won't matter. All the houses are gone with the wind.
Thanks for the feed-back. However, there certainly is at least an indirect claim in the article that this framing design could be used in seismic or hurricane country. This claim was made through a side bar in the article, which gave the plans for panels made of 2x4's and plywood on both the interior and exterior sides and steel rods running inside this box from the foundation to the top plate. As you pointed out, this design, with or without the extra panels, would not hold up in a severe hurricane, and the Dow Board sheathing would have difficulty withstanding a catagory 1.Yet, there are ways to build that could stand up to nearly any hurricane, and they certainly do not involve stick framing.
I have to agree Unsworth, as a framer/roofer in Mobile, AL (major hurricane country). We've already adopted stricter high-wind requirements that require use of U-straps, redundant ceiling/roof strapping, Go-Bolts, shear panel on exterior & interior, holddowns, you name it. Not to mention nailing @ 2" OC edges/ 3" OC field for roof and wall sheathing, and ceiling diaphragms.
While I agree that in a favorable or energy-efficiency is necessary climate these framing details could save money across the board, it's ludicrous to think houses here on the Gulf Coast could be built to withstand Cat 4 or 5 wind loads/ uplift while eliminating much of the "beef" within them.
Jason Pharez Construction
Framing & Exterior Remodeling
We spent a few days at a resort in Cancun, Mexico, where they're hit by hurricanes quite often. The buildings are two story poured in place concrete. They figure that the roof, windows, and contents are expendable. They just dig out, hose out, and re-build from the bare concrete when they get hit. They were working on a couple of the beachfront units when we were there.
-- J.S.