Decks and IRC

[Erby]

Did y'all see the segment on the CBS Early Show this morning about deck collapses. Some good info for homeowners and publicity for the issue!

[FrankWoeste]

Did y'all see the segment on the CBS Early Show this morning about deck collapses. Some good info for homeowners and publicity for the issue!

Here's the link to the video:

http://www.cbsnews.com/video/watch/?id=5109091n

[gtblum]

That was great until they decided to suggest that using screws would take care of the problem. What kind of screws? Where should you put them?

[Bill Kibbel]

That was great until they decided to suggest that using screws would take care of the problem. What kind of screws? Where should you put them?

Simpson's SDS structural wood screws.

[FrankWoeste]

That was great until they decided to suggest that using screws would take care of the problem. What kind of screws? Where should you put them?

gtblum:

They were showing a Simpson Strong-Tie fastener and you can contact them for specific design information. If you are interested in the general subject of deck ledger connection design including connection to an Engineered Wood Product (EWP) Rimboard that is bearing on a sill plate, then you can review this document:

http://awc.org/Publications/DCA/DCA6/DCA6.pdf

Frank Woeste

Professor Emeritus

Virginia Tech University

Blacksburg

[gtblum]

I think you guys missed my point. Think about who's watching that show.

Thanks for the info though.

[Bain]

That was great until they decided to suggest that using screws would take care of the problem. What kind of screws? Where should you put them?

gtblum:

They were showing a Simpson Strong-Tie fastener and you can contact them for specific design information. If you are interested in the general subject of deck ledger connection design including connection to an Engineered Wood Product (EWP) Rimboard that is bearing on a sill plate, then you can review this document:

http://awc.org/Publications/DCA/DCA6/DCA6.pdf

Frank Woeste

Professor Emeritus

Virginia Tech University

Blacksburg

I have a question, Frank. On page 12 of the AFPA document in your link, attaching a ledger board through brick veneer is prohibited. I realize that brick veneer isn't allowed to support anything other than its own weight, but it's exceedingly common for the fasteners to pass through the veneer and be anchored to the house's wooden floor system. In fact, I see that configuration on nearly a daily basis in my area.

What's the downside of installing fasteners through brick? Moisture infiltration through the holes?

[Bill Kibbel]

I think you guys missed my point. Think about who's watching that show.

Didn't you hear the woosh sound as your point shot right past me?

This is just one more thing those expert real estate salesfolk can scream at us about. "Your inspector is an idiot. It was on national news that drywall screws are fine".

[FrankWoeste]

I have a question, Frank. On page 12 of the AFPA document in your link, attaching a ledger board through brick veneer is prohibited. I realize that brick veneer isn't allowed to support anything other than its own weight, but it's exceedingly common for the fasteners to pass through the veneer and be anchored to the house's wooden floor system. In fact, I see that configuration on nearly a daily basis in my area.

What's the downside of installing fasteners through brick? Moisture infiltration through the holes?

Bain:

Yes, water infiltration is an issue. Also, since the brick veneer isn't allowed to support anything other than its own weight, the bolted connection would have a large "gap" between the two wooden members of the connection (house band and deck ledger). The "gap" would be composed of the sheathing thickness, an air space, and the width of the brick. The presence of the "gap", whatever it adds up to be, greatly reduces the structural strength and stiffness of the bolted connection.

We tested the case where the "gap" was only 15/32" (wall sheathing) and the results of that case are tabulated in the ledger table of DCA6. It's worth noting that tabulated bolt shear values published for years in the NDS and other wood design books are based on the assumption of no gap between the members. Good question.

Frank

[kurt]

I thought brick veneer support was not allowed simply due to "extraction", i.e., if the deck moves laterally away from the house, it takes the brick with it. Brick ties aren't intended to keep a couple tons of deck and people from moving sideways; they're just there to hold the brick to the structure.

On many levels, I don't know why the world doesn't go the direction of Gwinnett County, GA, and call for free standing decks. If the ledger is the constant and continuing concern, let's get rid of it per WJ's previous comment. It just makes sense, which of course is so often contrary to how the building industry works.

[Jim Morrison]

I think that's unnecessary. Think about it: If a fella is intent on banjaxing a deck job, he can do it to a freestanding deck just as well as a deck that's attached to the house. Granted, there will be fewer leaks if the deck is freestanding.

But what about this? People have been attaching decks to houses and getting it right for just about as long as they've been getting it wrong. It's no different than any number of other common defects that keep home inspectors feeling needed by the public. If AHJ's had both the resources and desire to live up to their job descriptions, then we'd see a whole lot more well-built decks.

You can mandate whatever you like, but if the rules aren't enforced strictly and uniformly, then the banjaxers of the world will keep smartasses like us in business.

And I , for one, thank Providence for that!

[hausdok]

I once sent Kurt a sketch of a way to support and flash brickwork and attach a deck to a house that had veneer. Wish I could find that danged sketch so I could ask Frank's opinion of the method.

OT - OF!!!

M.

[kurt]

I saved it somewhere, but I can't find it.........

[hmiller]

This is a very informative document on deck installations. http://awc.org/Publications/DCA/DCA6/DCA6.pdf

Thanks to Frank for posting it.

In reading this I came across something I did not know on page 12, where it specifically calls ledger board attachment to a cantilvered overhang a prohibited connection.

I find this interesting considering the fact that many split-level homes have a cantilevered upper story, which almost always has a upper level deck attached off of the kitchen/dining rooms.

Rarely, if ever, have I seen these free standing. Does anyone ever make a recommendation to add an additional inner support beam with posts and piers to take the load off the ledger, and the cantilvered floor system?

[Jim Morrison]

I find that in my area, many folks misuse the word 'cantilever'. A true cantilever is a beam supported only on one end. An overhang is a beam that is supported in more than one place and overhangs it's outside support by some distance. It makes a big difference. I don't suspect there are many cantilevers that are designed to also support exterior deck loads.

[FrankWoeste]

More deck problems in GA:

http://www.ajc.com/metro/content/metro/ ... lapse.html

[Ken Meyer]

Hi WJ.

I wrote up the lack of bolts on a deck ledger a while back. For the re- inspection I went into the crawlspace to see if I could see any of the bolts (cripple wall). Every nice new shiny bolt end was visible in the sheathing between the studs. I see this quite often when the interior section of wall is exposed-- scary stuff.

Yes, sometimes they miss. On this deck, that's not the only place they missed. Using hold downs to beef up the attachment to the house may have been a good idea, but the execution leaves something to be desired.

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[hausdok]

More deck problems in GA:

http://www.ajc.com/metro/content/metro/ ... lapse.html

Hi,

Well, when one looks at the gallery of photos with the article you can see that the ledger split right down the center and the bottom half pulled off the house. You can also see that the ledger was rotten and that there'd been water infiltration going on for quite a while. Line up bolts in a straight line and install a deck without flashing and you're just waiting for the day it collapses.

ONE TEAM - ONE FIGHT!!!

Mike

[FrankWoeste]

In reading this I came across something I did not know on page 12, where it specifically calls ledger board attachment to a cantilvered overhang a prohibited connection.

I find this interesting considering the fact that many split-level homes have a cantilevered upper story, which almost always has a upper level deck attached off of the kitchen/dining rooms.

Rarely, if ever, have I seen these free standing. Does anyone ever make a recommendation to add an additional inner support beam with posts and piers to take the load off the ledger, and the cantilvered floor system?

This JLC Q&A addresses some of the issues:

Download Attachment: JLC Attaching Deck Ledgers to I-Joist Cantilevers June 2009.pdf

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[Darren]

Here's a picture of a deck I did last week. Besides many other problems, the joist hangers are a classic.

This is a townhouse development where they are all the same!

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[Chad Fabry]

Here's a picture of a deck I did last week. Besides many other problems, the joist hangers are a classic.

This is a townhouse development where they are all the same!

That's a deck built by pros. Nice.

Here's a photo of a deck built by a resident in my jurisdiction. He'd never built anything before. I answered a few of his questions then handed him a prescriptive deck building document I copied from somewhere and a Simpson Deck Accessory Catalog.

He's pretty proud and I told him I'd share the photos with you folks.

Darren's photo is why I don't use the terms professional or amateurish in my reports any longer. I still use "crappy" or "built by a fourth grader".

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[kurt]

I hope you gave him a gold star.

Pretty nice.

[Jim Katen]

Here's a photo of a deck built by a resident in my jurisdiction. He'd never built anything before. I answered a few of his questions then handed him a prescriptive deck building document I copied from somewhere and a Simpson Deck Accessory Catalog.

He's pretty proud and I told him I'd share the photos with you folks.

What's with the strange post-to-girder connections?

- Jim Katen, Oregon

[Chad Fabry]

What's with the strange post-to-girder connections?

According to Simpson when they're nailed with 16 D nails, they're rated for 1100 lbs each. Bolted, they're rated for 1400.

[Tom Raymond]

Don't you just love the Popular Mechanic type. They totally imerse themselves in their project, and the results show it.

Tom