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Portland, OR
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Chicago, IL
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 Garage Trusses
[#28] Posted: 07/17/2010 - 8:49:00 PM |  |  |
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I don't argue.........I just logically explain to the designer why I'm right.
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Kurt in Chicago
"If I smell it, it goes in the report".............Phillip Smith...2012
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Gaston, Oregon
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Garage Trusses
[#29] Posted: 07/17/2010 - 10:23:55 PM | | |
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Quote: Originally posted by Matt FellmanQuote: Originally posted by Jim Katen
if we say, "We shouldn't be looking at this because it's a design issue." -- then we'll never see it.
Not at all what I said..... or, at least, not what I meant to imply. Of course, I look at the installation. I just don't second guess the design - meaning I don't calculate the loads, factor in the area where the house is built for snow/wind load, etc.
What about changes in use of the building that have resulted in changes in loading to the trusses? Surely, if you saw unusual loading on trusses that were obviously not designed for it, you'd at least mention it. Wouldn't you? Isn't that a design issue?
I guess I'm confused about your stance here because I see improper designs quite often. They're nearly never due to a mistake by an engineer, but rather are the result of a small modification made by a homeowner or builder during construction. When these things were done, no one thought that it would be a big deal, but the changes can sometimes result in a striking deviation from the plans. If an inspector is alert, it's not too hard to spot these issues.
Quote: If a truss is mangled during installation or modified by a homeowner or builder taking chunks out of it of course it's reported on. Damage is a very different thing than the design. . .
Yes, but in addition to physical mangling, there's also mangling of the design. It's done all the time. I've seen trusses placed in the wrong locations to make room for skylights, supporting walls moved to accommodate last minute whims of owners, girder trusses separated from the trusses they support by more than a foot, trusses raised up on little tiny pony walls, etc, etc, etc.
Quote: I just don't feel it's an HIs place to argue with designers....
I'm with Kurt. Who argues? I just state my position clearly. Besides, in most cases, it's not the designer who was at fault, it's the installer.
- Jim Katen, Oregon
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Jim Katen, Oregon
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Portland, OR
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Garage Trusses
[#30] Posted: 07/17/2010 - 11:42:39 PM | | |
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Unless I'm holding the plans in my hands I'm not sure how I'm supposed to notice a "small deviation from the plans". And, without running calculations on a truss I'm not sure how I'm supposed to know it's overloaded. Sure, "obvious" overloading, yes... but that's a pretty open ended term.
Jim, I don't think you and I are that far apart on this... it's just some terminology that's hanging us up. I don't ever look past and not report something that I see as a defect just because it's not what I'm there for. That's not at all what I mean when I say we're not there to argue the design. In a nutshell, I go in with the presumption that things are okay and, unless I see evidence otherwise, I don't mention it. The scenario I described above was in direct contrast to that and was my initial response to your question. In hindsight my wording could have been better.
In the end, I just try to stay away from elevating my client's expectations as to what I'm there to do.
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Kenmore, WA
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Chicago, IL
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Garage Trusses
[#32] Posted: 07/18/2010 - 05:00:45 AM | | |
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There's some old frame bungalows on the NW side that have 'em on 32" centers, an (approx.) 4:12 pitch, and 3 layers of asphalt!
Testimony to the miracle of old growth lumber.
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Kurt in Chicago
"If I smell it, it goes in the report".............Phillip Smith...2012
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Oswego, NY
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Garage Trusses
[#33] Posted: 07/18/2010 - 06:40:06 AM | | |
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And of course, we have the same here. Difference being the 5/4 or better decking, on top of the old growth lumber rather than 3/4 plywood or OSB. We wouldn't expect the same from a 24 or 32 on center plywood decked roof, right?
I probably should have included that in my question.
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I'm Gary Blum and I approve this message
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Lexington, KY
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Oswego, NY
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Collins, NY
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Garage Trusses
[#36] Posted: 07/18/2010 - 08:43:48 AM | | |
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Quote: Originally posted by BainQuote: Originally posted by MarcQuote: Originally posted by Matt Fellman
I studied civil engineering when in college and ran loads on so many imaginary trusses I could do it in my sleep. The one thing I remember to this day is that I have no business scrutinizing the design of a truss with the limited information available on a home inspection. I'd like your opinion on whether to call it when you see trusses mixed up with custom cut lumber on a single dwelling. It's pervasive here but I call it everytime. No prescriptive method covers it. It's a result of making a decision to use trusses for the roof but ends up needing lots of custom cut rafters, braces, scabs etc in order to have something to nail the decking onto. I call it 'tribal construction methods'. Marc There's a company here that's ranked 47th nationally in units sold, and they do exactly what you're talking about. They set the trusses, then nail a bunch of rafters to the ends of the trusses to form hips. Like you, it always looks like a couple of sixth graders assembled the roof structures, but the AHJ passes the things, and, to my knowledge, there haven't been any failures. I'm not saying you shouldn't bust a builder for doing it, but around here, it's a waste of time.
Uhm, if the place has plans an engineer signed off on blending trusses and rafters.
Tom
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Tom
http://clearcreekhomeinspection.com/
Life is tough enough as it is, it's tougher when your stupid. Don't do stupid things.
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Lafayette, Louisiana
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Victoria, British Columbia
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Garage Trusses
[#38] Posted: 07/18/2010 - 9:39:38 PM | | |
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Quote: Originally posted by ryanpHello, I am trying to find information on where a splice can be made in the bottom chord of a truss. I inspected a house today and the garage was 20 feet deep and had the bottom chord of the trusses spliced with two 1/2 inch pieces of plywood nailed to each side right in the middle of the chord. Is this acceptable? I am trying to find more information on this for future reference. Thanks for the help ahead of time. Here is a photo. Sorry it is a little blurry. Click to View
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I'm sure the plywood gusset and nails are fine if that member only sees horizontal tension. But should it not also be capable of carrying a reasonable load as well, such as the weight of a 200 lb builder?
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Hollidaysburg, PA
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Garage Trusses
[#39] Posted: 08/11/2010 - 10:23:22 AM | | |
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When I was in school we made many trusses for differant things, my teacher told me site built or homemade trusses in his mind where stronger than ones made at a truss factory if they where prob, built. The right size gussets the right glue and the right nailing pattern and good straight wood. And I agree with him.....my father would not let me make his trusses for his breezeway and he bought trusses from the local truss factory and you can see alittle sagging and twisting already and they are only 4 years old. I went to look at a pravilian I help make when I was in school to see how it was holding up after 17 years and it is still in great shape, I will be building a pole garage in about a month or two and I will make my own trusses but then again I dont need it inspected...........I think if you have the correct messurments for all the spans and use good wood and construct them well sitebuilt or homemade truss are great........but thats just my 2 cents
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Kenmore, WA
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