Ledger board attachment

[alindquist]

Quick question...
My neighbor and I are going to start a deck project this week and I'm wondering how I should go about attaching the ledger board. What we have is a slab on grade house, wood framing, with brick exterior... The brick does extend down far enough to catch the entire ledger board. Can I attach directly to the brick with wedge anchors or some kind of concrete screw? Do I need to penetrate completely past the brick and into the foundation (there is a 1"-2" brick pocket)? Should I just pour footers at the house and and set the ledger board on top? We are down in the Florida Panhandle... The rest of the project I'm pretty confident with but I have never built a deck with this situation.

Thanks for the help... Aaron

[Glenn Mathewson]

The IRC (residential code) does not allow brick veneer to support any loads other than the dead load of the bricks above.

I would consider self supported in your case, since the existing structure is slab on grade, you may not have to go very deep to reach undisturbed soil. Although, depending on your height above grade, you may have issues providing lateral resistance, since you are not solidly connected to the primary structure. There are many other design approaches to your problem, but none are very simple, and none involve connection to the brick.

Brick veneers always create numerous issues in deck construction, I would either consult an engineer, other professional or rigorously do your research and homework on this one, as this response does not by any means provide you a complete design approach.

Good luck, and be careful...the ledger connection is serious issue.

[Deckdog]

Aaron,
If you have room, I would come out from the house about 2 feet and install a beam below the floor joists. Then install bracing from the posts to the joists, so the deck cannot move.
Check out "Prescriptive Residential Deck Construction Guide" by American Forest & Paper Association at this site (near bottom of page). http://www.awc.org/Codes/dcaindex.html

Lots of information in this guide.

Joel

[Rick Jeske]

Check out "Prescriptive Residential Deck Construction Guide" by American Forest & Paper Association at this site (near bottom of page). http://www.awc.org/Codes/dcaindex.html


Deckdog, thanks for that link. Like alindquist, I also plan to attach my deck to my house with brick veneer. Is that completely outlawed now? I have seen hundreds of decks in my subdiv which are built this way. I plan to thru-bolt the ledger snug. I have only ever seen one free-standing deck around and it was pretty wobbly at best.

Here's my dilemma. The building official offers no help except to say that decks must conform to the "latest code."
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[Deckdog]

Hi Rick,
When I am building a deck on a brick house, I through bolt the deck into the house floor framing. This gives the deck the stability that it needs, without excessive bracing.

Then I post the ledger at the house with 4x4's. This takes the weight off of the brick.
If you have too many windows and doors to put the posts at the house, you can come out from the house a couple of feet and install a drop beam.

Joel

[Rick Jeske]

Thanks, Joel

Can the 4x4 posts sit on a new concrete patio? I could live with that. Maybe a 4x6 would like nicer, by matching the other 6x6 posts. I could even make them decorative with a router. Coming out 2 feet and dropping a beam, however, will prevent doors from opening and people from standing underneath.

Are there exceptions to the rule? I would think the weight on the brick would be far less significant than the loads on the fasteners.

When you thru-bolt, do you tighten to a specified torque, to prevent over torquing?
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[Deckdog]

Rick,
Years ago, we used to always bolt decks to brick veneer houses and never had any problems with them.
The code now will not allow brick to support the weight of the deck. The bolts (1/2" dia.) can support the weight, they just have to be spaced properly, usually every 12 to 16" alternating one up and one down about 2 inches from the top and bottom.

Placing the 4x4, 4x6, or 6x6 on the patio should be fine. Technically, each post should have it's own footer, but I think it is safe to assume that the patio rests on the house footer. Just be sure to anchor the posts at the top and bottom with some galv. metal brackets, or use a standoff base that is bolted into the concrete.

For tightening the bolts, just get them nice and snug. The washer should just start to compress the wood fibers.

Good luck with your project,
Joel

[Glenn Mathewson]

years ago, I also attached ledgers to brick veneers, but that does not mean that it wasn't prohibited by code. It just means we were all doing it wrong...like it or not, it's not new. It is, however, more noticed by code professionals now than in the past.

1967 UBC (Uniform Building Code) Section 2902
Definition: "Veneer is a NONSTRUCTURAL facing of brick, concrete, stone, tile, metal, plastic or other similar approved material attached to a backing for the purpose of ornamentation, protection or insulation"

By definition, a veneer is never intended to perform in any structural capacity other than its own dead load and the dead load from above.

As someone who regularly sees both structural masonry and veneer masonry, trust me, the nuts and bolts of the two are considerably different. It is not that the brick cannot support the vertical load, it is that veneer brick is not designed to resist the bending stresses that occur in the vertical plane of the brick. The same way that a 2x4 temp post will start to bend if overloaded, the brick does the same. the cheap little metal ties that are "supposed" to be installed in a pattern behind the veneer is only meant to resist small forces, and rarely are these ties inspected...so do you even know they are there? Structural masonry has considerable more restraint to the bending of the wall under load and is inspected for proper construction. (grouted cells, rebar, ect)

No, the bolts will not carry the full vertical load. The bricks could be up to five inches thick with up to 4" allowable air gap behind them. this would make the moment arm on the bolt about 9 inches; not a practical engineering feasibility. Imagine that the brick was not there and you through bolted the ledger, but the ledger was spaced 5 to 9 inches out on the end of the bolt, off of the rim. Can you imagine the leverage and bending that would occur on the bolt, it doesn't occur when the brick is there, because the brick resists the force (structural). It would take a hefty bracket to handle that kind of moment (torque), not a series of bolts.

Again, ledger attachments through brick veneers are very difficult and require a design professional.

The suggestion of connection through the brick for lateral load resistance is okay, as long as the gravity (vertical) loads are supported by another means. (as has been suggested, posts, dropped beam, etc.)

"We've always done it this way", means we've always been lucky. This goes for me too.

Glenn M

[Glenn Mathewson]

I will add, now that the official response is posted above, one "realistic" thought. (sham on me, an inspector, for thinking "realistically" ha, ha!)

1. If the deck ledger is only a couple feet above the brick ledge (foundation) then there is likely not much distance for the lateral bending to occur, and it's not really that big a deal, in my opinion. (like a really short 2x4 temp post can be loaded more than a tall one) The higher you go up the veneer face, the bigger the problem gets.

Now just convince YOUR inspector of that!

Glenn M.

[Rick Jeske]

If the deck ledger is only a couple feet above the brick ledge (foundation) then there is likely not much distance for the lateral bending to occur, and it's not really that big a deal, in my opinion. (like a really short 2x4 temp post can be loaded more than a tall one) The higher you go up the veneer face, the bigger the problem gets.

Thanks for all the responses guys. My basement is a walkout, so the ledger would be up ~8 ft or more from the footer. I understand the concern for buckling brick, that's why the ledger should not bear lateral loads, only compression loading from the attachment bolts.

Deckdog seems to have hit upon a suitable compromise using posts at the house, yet tying to the house's frame to provide lateral stability.

It seems there is not homogeneity across the country regarding ledgers on brick veneers. I have even seen whole room additions and covered porches in my subdiv which use ledgers on brick veneer. This is 70's and 80's work however. I'll have to "sneak around" and see what the new homes have. I guess that is one good reason for using brick only on the facade, the rear is sided making ledgers easy.
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