Question about truss arrangement

[jkogel]

Here we have a brand new home, hip roof, built to the local minimal code requirements. Does anyone see a problem with the way the lower ends of the 2X4's-laid-flat rafters are supported? There are short 2X4 cleats nailed to the supporting truss. I suggested there could be additional supports under these cleats, or they could be held up better with metal brackets. The buyer will run this past the builder. I warned him what the builder will say. Nit-picky?

John Kogel
www.allsafehome.ca

[Ted Allen]

I see some added support in the rafter area of pic one, whats up with that? Other than that...... It looks OK to me.... Then again I am in no way affiliated with NACHI......

You can count on many more responses from the NACHI elite.

[Bruce A. King]

At least they have cleats. If the cleats are properly nailed to the trusses, I don't see a problem. I can't see for sure that there are cleats in all of your pictures. The span of the flat 2x4's needs to be kept reasonable though (less than 5 feet would be a good guess or in a snow region less than 4 feet) but depending on the "on center spacing" also.

We have a tract builder around here and AHJ's that let the framer bevel the end of the flat 2x4's with the thin bevel barely resting in the gap between the sheathing and truss.

I always write it up but have never been back to see if anything was done about it. Too many homebuyers believe the "it meets code" crap that they hear quite often.

[Erby Crofutt]

Don't let it be a pissing match between you and the builder. Get an answer from an authoritative source that the builder can't refute. Builders can always argue with "your opinion" and play the "it meets code" card. Citing a reputable source, such as the Canadian Wood Truss Association makes it really hard for him to refute and trumps the "code" card.

As you're in Canada, this link would be appropriate for you.

http://www.cwc.ca/NR/rdonlyres/828D8...ufacturing.pdf

Look at the hip roof stuff and visualize where the cleats are added.

Looks like a typical hip roof step down truss with cleats added for nailing the sheathing or cross bracing the trusses, kinda like adding nailers for sheetrock. Not really part of the structural support, unless you want to call it cross bracing for trusses.

Contact the Candadian Wood Truss Association with your picture. They can REALLY tell you if it's a problem or just something normal.

http://www.cwta.net/
Jerry Cvach, CWTA Secretary
Telephone & Fax: (403) 271-0520
Email: cwta@telus.net


Or the Western Wood Truss Association of British Columbia
http://www.wwtabc.com/index.htm

info@wwtabc.com

We can guess. They can provide an answer that the builder can't refute or tell you you're full of it. One of the two, but it'll be the right (defensible) answer. And provide you good future guidance with a defensible source.

Let us know what they say.

[jkogel]

Thanks all. Erby, I've bookmarked that pdf truss info, thank you.

[Erby Crofutt]

Let us know what the truss associations have to say about it??????

[jkogel]

Originally Posted by ecrofutt

Let us know what the truss associations have to say about it??????

Here's a copy of an email I received today.

"John Kogel,
I've enclosed an old standard WWTA installation detail sheet. On page 6, there is an over-view of typical truss roof framing details. The enlarged detail D2 on page 7 comes closest to describing the situation in your e-mail. I believe you are pointing out the 2x4 strapping connection to the actual 2x4 (on flat) hip ridge. These will come together on the same plane and won't necessarily connect directly over a truss for support. The framers have probably added a "cleat" underneath the connection to strengthen this point.

The 2x4 strapping is spaced @ 24" o.c. The most that this connection will ever carry is 2' of square roof loads - it's really less than this because "H-clips" transfer the load and this joint connection would be the end connection of a 3 point multi span piece of plywood. You could probably get 2 or 3 toe nails into this connection which would be good for around 225 to 335 lbs.
You can work out the math backwards, but the 225 would be equal to around a 135 psf ground snow load, which is bigger than virtually anywhere except ski hills..

Bottom line; this isn't anything to worry about. "

Keith Ohlhauser, P.Eng, P.E.

Engineering Services
AcuTruss Industries (1996) Ltd.
2003-43rd St, Vernon, BC, V1T 6K7
Phone: 250-545-3215 ext. 2260
Fax: 250-545-2953

So there we have it. The Drop-in purlin truss would be over-kill.

[Mike Truss Guy]

I concur. There are many different ways to frame a trussed hip system. Sometimes they use what is know as a purlin gable truss that braces the top chord and allws nailing of the sheathing. All trusses must be designed by an engineer. The truss calcs are usually sent to the building department as a part of the building design submittal.

[Erby Crofutt]

Hey Mike. Welcome to the NACHI board.

[relliott]

Originally Posted by Mike Truss Guy

I concur. There are many different ways to frame a trussed hip system. Sometimes they use what is know as a purlin gable truss that braces the top chord and allws nailing of the sheathing. All trusses must be designed by an engineer. The truss calcs are usually sent to the building department as a part of the building design submittal.

Mike you should post your link here.
I suggest everyone visit Mikes site.
Click on his name to visit his site.