I am a owner builder in the initial design phase of a project, and am considering the merits/cons of truss roof construction vs. stick building the roof. The roof has a 10/12 pitch, and the general design is the type typical of Frank Betz Assoc. I don’t intend to use the attic for anything other than light storage. I realize that contruction time would be reduced with trusses, but am most concerned with cost/benefit and structurual soundness.
Thanks for you input!
Grand Island, New York
Replies
I'm sure others, like especially BossHog will jump in, but I think trusses are much better than stick built. Structural soundness should be better, time to build the roof and get the sheathing on will be much shorter, and I believe trusses are cheaper than stick built. With stick built, among other things, you are relying on the structural strength and integrity of a few members, whereas with trusses you have an engineered, integrated system composed of many members. Anyway, that's my opinion. (I am not an engineer.)
I am an owner, builder, engineer in NY. I am adding a second floor to my house utilizing trusses. The cost of the trusses was probably a little more than the raw material for a stick framed roof. However, there is an appreciable labor savings.
What sealed the deal on the trusses was the flexibility of not having bearing walls under the trusses. Ceiling joists are eliminated..
In theory, both systems should be designed to the same level of safety/structural soundness. There are ways to skimp with either method that will result in a lower level of robustness.
One key consideration is "load path". (I don't know Frank Betz Assoc. so I apologize if that is supposed to help me visualize things) To my way of thinking, trusses tend to be better able to span over things and are more convenient to avoid alot of interior post supports and therefore alot of individual posts and cross beams. With trusses, you can usually reach from outside wall to outside wall and are often better aligned with the foundation system or convenient load bearing elements. Stick framing tends to get into alot of transfer beams and tracking loads all over the place to get them down thru a building.
In my estimation, if you have the depth available (such as with 10/12 pitch) I would expect trusses to be the "better" way to go.
http://images.google.com/images?hl=en&q=Frank%20Betz%20&btnG=Google+Search&sa=N&tab=wi
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I've never heard of Frank Betz either. Would you care to give us some references or more info?
I'm sort of the unofficial resident truss guy at BT. But I don't believe that trusses are the best answer for EVERY house. A lot depends on the style.
I see it like this:
With trusses, you have less need for load bearing walls. You've got an engineered system and someone to back it. Hang around any home building forum on the internet and you'll find a lot of discussions about moving load bearing walls when remodelling. So I think this is an important issue.
One of the downsides to trusses is availability - You have to order them ahead of time. There's less margin for error. You can't cut them to fit in most cases.
With stick framing the lumber is more readily available. You can go pick up another board or 2 anytime you need it.
I think in general trusses are stronger than stick framing. Primarily because little thought is given to the connection when buildings are stick framed. (That's just my opinion - I can't back it up with anything)
The style of the house makes a lot fo difference too. Some houses just don't work well with trusses because of the way the 2nd floor rooms are built into the roof, for instance. Other houses have few places where you could pick up bearing for stick framing so trusses work better.
Local traditions play a role too. Around here virtually no one stick frames. Try to make a framer stick frame something when he doesn't want to and you've likely got a battle on your hands.
The reverse is true in other areas - If stick framing is the norm, the framers will resist using trusses.
If one or the other is the "norm" for your area, using the other one could count against you if you ty to sell the house.
So there's my $.02 worth. Hope you found it helpful.
Well, I went to Mr Betz's web site (http://www.frankbetz.com/index.html).
And there are some interesting designs there. Some are better, some are worse for truss design overall (and I trust BossHog has at least one horror story of "worse" in similar circumstances <g>).
The "test" you may want to apply is "how simple is the roof?" Trusses can help "magnify" the simplicity of a simple roof. That translates into improvements in the process (if still limited by you can have any two of speed, price or quality). If your roof were to have all the dormers, plane chnages, and other fiddly-bits of the image on the Betz homepages--that's not "simple."
Now, as a designer, I'm not a fan of steep roofs on single story houses. Part of that, is that steepness invites some future party to imaginge that adding a half story in that space will be relatively easy (which it rarely is). Part of that is my climate--a big empty, very hot, box on top of the house doesn't "do" that much for the house (and it's a lot of acreage of shingles to attract hail, branches, downbursts, that sort of thing).
But, that's just me, as a desinger, too. Others differ. It's your design, you're allowed to choose what you want.
I have built a few of Frank Betz's houses, lots of steep roof area, two story rooms like the foyers and living rooms.
The last one I framed was a truss roof and it turned out good. It had a attic truss to hallway in the house tie in that was a little time consuming but all in all was a nice house when done.
I can take some pics of the finished house on the outside if you want to see the real live thing. The house plan was called the Hollister it was 2293 sq ft.
Usually in his prints he has roof framing drawings so that will give you an idea of what stick building the roof is going to take.Can't you hear the violin playing your song.
I googled it up too, and saw glitzed up McMansions, but they were somewhat appealing, rather than repulsive. Quite an eclectic mix of details and styling though...
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saw glitzed up McMansions, but they were somewhat appealing, rather than repulsive
Well, the latter is why I did not think McMansion--just cluttered "Builder's Style" with some considered attempt at panache.
I was more looking at the roofs, and very few were 'straight' gable construction--where trusses are really economical (did not see that many single stor plans, either).
Oh well, that's life.Occupational hazard of my occupation not being around (sorry Bubba)
All the roofs pictured on that link are well suited for trusses.
Truss designers don't need simple gabled roofs to make them economically feasible.
blue
Truss designers don't need simple gabled roofs to make them economically feasible
Ah, but, sometimes the truss "customers" do. Particularly those who do not plan out their details & framing the like in advance. Now everyone understands the efficiency gain in pre-building many components.
And, this is hugely speculative, as we only have a terse description of OP's present roof design.
And, I'm likely "projecting" too much forward, 30-40 years down the line, when some future owner just starts in on that "half story addition" to find out the bottom chords of the trusses are not floor joists, neither that the interior partitions below them are load bearing walls. Probably a tad too pessimistic of me.Occupational hazard of my occupation not being around (sorry Bubba)
IMHO you will probably save money going with trusses. There will be less clutter in your floor and wall framing, as most, if not all, of the points loads will be eliminated. You may have some girder point loads to accommodate, but in general the framing will be simplified by using p.e. trusses, thus saving time and materials such as built-up posts, lvls, hangers, etc. not to mention labor which will probably be your biggest savings over conventionally framed roofs. There are situations which lend themselves to framing conventionally (dormers, small shed roofs, etc.) and those areas are sometimes more cost effectively hand framed, and you can use a combination of both as your project dictates. As far as integrity, I'd say the trusses roof is less likely to be problematic due to human error (cut, notched posts and lvls supporting load paths due to mechanicals, etc.) If your thinking of adding on in the future (into the roof space) you may be able to specify attic trusses for those areas if your plans lends itself to accessibility to that area.
Regards!
I recently bid on a 2900 sq' Frank Betz house...the roof was so cut up, and steep, that I didn't even consider trusses...maybe I should have, do they make 'em for eyebrow dormers? I need a dump truck, baby, to unload my head
i'm not taking sides on the truss vs stick frame, but I would comment on the mechanical trades chopping up structure.The ones who are ignorant enough to chop up stick framing are just as likely to chop up trusses, in my experience
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The ones who are ignorant enough to chop up stick framing are just as likely to chop up trusses, in my experience
I've never seen any of them hacking up roof trusses. They all seem to think they can hack through floor trusses though.
blue
I'm speaking more to the floor and wall scenerio (drilling holes thru floor micros, a notch here, a notch there, this toilet will work if I just take the bottom third of this piece of wood out). In general, the more load you put on the outside walls of a building the better imo. I suppose in the south or slab construction it may be a different situation with hvac equip. in the attics, but then again the truss mnf. should fab the trusses accordingly for clearance and xtra loading as specified by the designer. I suppose a true hack will saw thru anything to make his day easier.
"I suppose a true hack will saw thru anything to make his day easier."That's the general idea I was trying to get across
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Who's going to be framing the house? I would ask them which way they'd rather do it.
Not to make a disparaging implication toward framers but, the answer from them might boil down to whether they want to be paid to frame it themselves or have the $$ go to the truss guy.
I do think that framers in general may be well suited to advise on the feasibility of stick vs. truss but one should keep in mind the interest of the party being asked and how that shades their view.
McMansions. Why?