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Jeff Eastman
05-15-2007, 06:54 PM
..........

Bruce Breedlove
05-15-2007, 10:04 PM
I see lateral bracing on the two posts to prevent movement perpendicular to the rafters.

David Banks
05-16-2007, 05:01 AM
Jeff. Do you have a pic of the attachment to the house?

Jerry Peck
05-16-2007, 05:31 AM
Bruce pointed out the knee braces, but that's more to keep the beam/post square and in alignment than anything else.

There are no diagonals nor any diaphragm to resist racking of the roof system.

A big wind will blow that thing down, hopefully you don't get big winds in your area.

Bruce Breedlove
05-16-2007, 01:35 PM
Correct. The knee braces are more to keep the post-beam connection square. Depending on the quality of the other connections they may also resist racking of the roof structure to a degree (most likely a small degree). A diagonal (1X4, 2X4, metal strip, etc.) nailed across the underside of the rafters would be best for that purpose.

I suspect what Jeff is concerned about here is really the roof structure pulling away from the house. He said the rafters were nailed to the eave board. The connections (rafter to house) could be greatly improved by installing hangers. But then what are you attaching to? The eave board itself may not be sufficient. Is it a 1X_ or a 2X_?

Another component that could be improved is the beam above the posts. I see nothing to resist beam rotation. A tall, narrow beam on top of posts could easily rotate out of position. For example, someone running toward the house (e.g., kids playing football) could run into a post and push the top toward the house, causing the beam to rotate and the entire roof structure collapsing. Knee braces parallel to the rafters would help.

And then there is the matter of uplift. I don't see anything securing the rafters to the beam.

Jerry Peck
05-16-2007, 03:00 PM
Jerry,

Exactly what do you mean a "diaphram". I understand the diagonal bracing, but diaphram? Do you have a picture of one installed?

Jeff,

Think of a picture frame with no picture in it.

Stand it on one side and push toward one upper corner, the frame will 'rack' diagonally into a parallelogram.

Now, with a picture in in (especially the old fashioned way where the canvas is pulled taunt) the picture frame is much more resistant to your pushing, it stays true and square until a lot more pressure is applied.

Now, replace the picture (the canvas) with a piece of plywood, the frame can be pushed and pulled and you would have one heck of a time trying to make rack out of square and into a parallelogram.

Matt Fellman
06-24-2007, 04:54 PM
Wow! Those outer posts and beam look large enough to support 10 elephants dancing. Particularly odd given the skinny rafters. At least when it falls off of the house is won't blow to far away.

Rick Hurst
06-24-2007, 05:28 PM
Sometimes bolts are just not enough.

Jerry Peck
06-24-2007, 06:24 PM
Rick,

Sometimes you feel like a nut ...

Sometimes you don't!

:D

Rick Hurst
06-25-2007, 12:16 AM
Jerry,

That great!

Wished I could have came up with that comment as my client was standing there in amazement.

Seems the seller bragged a bit much as being the best arbor builder in town just minutes earlier.

Robert Schenck
06-27-2007, 10:42 AM
Jeff, … I’ve come across situations like this as well. And to me, it’s an accident just waiting to happen. Bruce (B) described the situation very well, and I agree with him 100%. All too often carpenter wanna-be’s build things to improve the looks of their house, which is cool…. But fail to look at the structural integrity of what they just built and the consequences (liability issues) that can arise.

(1) If the beam twists or topples, (2) the rafters will follow, and we all know what happens to (3), …. One Two Three it all falls down. :(

At a minimum, I’d place metal support plates on both sides of the Post-to-Beam connection, and place hangers on the Rafters-to-Eave connection. Is that 100% safe ? No – but it’s better than nothing and as it stands now.