# deck - beam to post connection (??)



## cibula11

Some prefer that the beam sits on top of the posts so that the load of the deck is resting on the post, not the carriage bolts. 

However, attaching the beam to either side of the post is an extremely common practice by professionals. 

Is your beam already put together? I've not seen a beam attached to only one side of the post and not sandwiched between the beam. 

It sounds like that could be a problem, but maybe it has been done that way.


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## brocasArea001

Thanks for the reply...

No the beam is not put together, nor the post set. (my wife just called and said the lumber has just been delivered)

All that's assembled are 12 4 foot footings with a 4x4 post anchor set in concrete in each.

Because of the height problem the joists will be hung from the beams rather that sit on top. Is sandwiching the post between 2 2x's still applicable in this scenario because they would only be hung from the inside 2x? (would I need to install a 4x4 every couple of feet down the run of the beam between the posts?)


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## WNYcarpenter

I'm not 100% certain I understand, it sounds like your piers are too high to more than a miniature post under the beam, but not quite high enough to set the beam directly on the pier. Close???

Can you be a little more specific...what's the actual measurement between the bottom of the beam and the top of the pier where the grade is closest to the deck....a picture would be even better!

One way would be to use a wider rim joist that sits diectly on the pier nailed to the end of the beam and shim under the beam with a chunk of 4x4. I would recommend that before bolting to the side of an extremely short post.


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## WNYcarpenter

cibula11's suggestion should work for you (sandwiching the post and through bolting. Hanging joists off a beam is common practice. It's a little more time consuming, but in your case you don't have much choice. Make sure you use joist hangers and the appropriate fasteners.

atlanticwbconst, if he picks up on this thread, will have good advice as always and often times posts links to manufacturers and their suggested installation procedures.


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## brocasArea001

You are correct. The height of the pier was intentional too low and impresise. If I was precise in pouring my piers then I have poured them at the exact height so I could sit the beam directly on the pier and forget the post. 

However the plan I followed indicated that getting the exact pier heights accross the entire deck to be at the perfect height is very difficult so it suggested using a short post and attaching the beam to the side of the post at the appropriate height to ensure everything is level, and then trimming the tops of the posts to be level with the beam.


The height of the pier is about 2" off the grade. The max height beam + pier + decking is 10" (lowest point). The joist would hang from the beam. 

Sitting the beam directly on the pier would be okay if all my piers were at the correct height, but I'm willing to be they are +/- inch or two.

Perhaps using a shim is the best option is using a 4x4 shim and sitting the beam on the shims, as you suggest. This shim sizes would like likely vary between 2-4" accross the entire deck (because of a slight grade).

Here are a couple of crude pictures I drew up .... they are brutally out of scale, but hopefully you get the idea.

The first photo is what is suggested by the book. The green in the anchor. The brown in the post. The grey/green in the built up beam. The blue is the carriage bolts. The entire beam is on the outside of the anchor/post.

The second photo is what I think you suggested. With the brown being part being a shim (or a really really short post), and the beam sitting inside the anchor with carriage bolts.


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## brocasArea001

WNYcarpenter said:


> cibula11's suggestion should work for you (sandwiching the post and through bolting. Hanging joists off a beam is common practice. It's a little more time consuming, but in your case you don't have much choice. Make sure you use joist hangers and the appropriate fasteners.
> 
> atlanticwbconst, if he picks up on this thread, will have good advice as always and often times posts links to manufacturers and their suggested installation procedures.


 

Thanks WNY.... not being even close to a structural engineer or carpenter the sandwhich post makes me wonder....

Will not the inner 2-by of the beam will be the only part of the beam supporting the joist? What does the outer 2-by (the outer slice of bread of my post sandwhich) do for the structure. I can see this working if the joist sit atop of the sandwhich but attached the the inner?

Thanks.


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## WNYcarpenter

Pic #2 is the way to go. It's actually a pretty darn solid attatchment. You should be fine!


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## KUIPORNG

Option 2 seems to feel better in terms of safety and easier to install... provided the shim being minimium at certain height... as if it is too short... I think the shim may hot be strong enough... I would do option 2 if it can be done... before trying option 1...


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## brocasArea001

thanks ....

off to HDep to exchange 22 7" carriage bolts for 6" ones....that should save me about 15 bucks.... also I should probably get some spacers for the built up beam so the width will be equal to the anchor width (nominal 4-by lumber).

Again...thanks for the suggestions.


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## Jeekinz

Brocas, can you post the title of the book so I don't buy that one?


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## brocasArea001

actually this book wasn't the only to suggest this method....but most sources of info have the beam either notched in a 6x6, sitting on top, or have the post sandwiched between 2-bys.

Here is a link that describes bolting the beam to the side of the post...

http://www.cedaroutdoors.co.uk/deck_building/

so...I'm still a bit confused. 

What if one of my shims is only 1 inch thick? Will it crack, compress over time, rot?

What if I want a post to extend above the deck? and cannot place the joists on the beam due to height restrictions, and am using 4x4 posts?


I'm really beginning to wish I planned for 6x6 posts.

The book was: Decks - Plan, Design, Build by Steve Cory
another book: "Decks" by Creative Home Owner Press also shows this a choice.


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## WNYcarpenter

brocasArea001 said:


> Thanks WNY.... not being even close to a structural engineer or carpenter the sandwhich post makes me wonder....
> 
> Will not the inner 2-by of the beam will be the only part of the beam supporting the joist? What does the outer 2-by (the outer slice of bread of my post sandwhich) do for the structure. I can see this working if the joist sit atop of the sandwhich but attached the the inner?
> 
> Thanks.


 By sandwhiching you are eliminating the interior 2x from the beam...the end result in actuality is that you don't even have a beam at all, just a left side and right side bolted together at the beam....This practice is done when the joists ride atop the faux beam. In your situation, you'd have to increase the dimension of your 2x up to code allowing one single member to carry the weight of hanging joists. I really wish I had a cad program to ease the translation!


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## KUIPORNG

With WNYCarpenter explanation, now looks like you should go with option 3 which is sandwiched beam/post... with empty inner beam... then you can solve your extended posts issue, footing being too high...etc. issue... it make sense to me... may be you need to go back to HD to get those long bolts again...


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## Jeekinz

Check this out http://www.cornerhardware.com/home_improvement_articles/deck_framing_details/49

I don't have any good pics of my deck. It was built by an iron worker that worked on NJ/NY bridges and tunnels. I added a sunroom on it and the sunroom company couldn't believe how well built it is. They just threw the sunroom right on top without and structural modifications.


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## brocasArea001

KUIPORNG said:


> With WNYCarpenter explanation, now looks like you should go with option 3 which is sandwiched beam/post... with empty inner beam... then you can solve your extended posts issue, footing being too high...etc. issue... it make sense to me... may be you need to go back to HD to get those long bolts again...


I think I now own every freakn' 7" and 6" galvanized carriage bolt at my home depot...I cleaned them out. Here is the "plan".....

I can't get a wider beam because the grade will not allow for it at the highest point. (I might be able to squeeze in a 2x8 but the lower 1inch or so would be in the dirt...I could excavate..but I already have piers). 2ndly I just bought a sheet of 4x8 PT plywood to use as spacers for my built up beam for option 2. (HD didn't have anything smaller and wouldn't offer....so if anyone needs 3x7 piece of PT plywood let me know hone.

Here goes nothing.....now where did I put my hammer...


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## cibula11

Since you are attaching your joists to the beam (with joist hangers I assume), sandwiching the post will do you no good. Your option of combining your beam together and then sitting that on the pier should work fine. 

If you need to build a couple of piers up just an inch or so, you can shave some shims out of treated 4x4 or use composite shims. If you have to go much higher than an inch or two, I would suggest constructing an actual post for which the beam will sit on. 

It sounds like you have a good plan.


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## KUIPORNG

Good to hear you are get moving... as usual... many ways will work... give us some pictures when its done...


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## Vincer

Just my 2 cents, if you are worried about stubby posts inside the anchor ... why not just use concrete inside the anchor to boost the pier up to the correct size? So if you are doing what is shown in picture #2, then why does the shim have to be wood, if you are afraid it will fail? Just pour up to the height where the beam would sit.

Also on the point of stubby posts .... a lot of pre-formed concrete piers come with a piece of wood nailed to the top. Posts or post anchors then get attached to that little piece of wood... why would that wood (which is like a cut off piece of 2x6, with grain running horizontally) be able to be "strong enough" and yet a little stubby shim/post would not be?


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## CraigV

Vincer said:


> Just my 2 cents, if you are worried about stubby posts inside the anchor ... why not just use concrete inside the anchor to boost the pier up to the correct size? So if you are doing what is shown in picture #2, then why does the shim have to be wood, if you are afraid it will fail? Just pour up to the height where the beam would sit.
> 
> Also on the point of stubby posts .... a lot of pre-formed concrete piers come with a piece of wood nailed to the top. Posts or post anchors then get attached to that little piece of wood... why would that wood (which is like a cut off piece of 2x6, with grain running horizontally) be able to be "strong enough" and yet a little stubby shim/post would not be?


The problem is that the OP is using a bracket that was designed only for posts, with the intent of it supporting a beam, and a short shim/post in zome combination. Every idea presented in this thread is a problem and likely would not pass code inspection, as this is a misuse of the bracket. 

Planning avoids having to ask how to get out of the corner you've painted yourself into. Happens to all of us, I'm certainly no exception. It's often better to simply admit defeat, rip out the old wrong work and do it right. I've gone both ways, and often tearout/redo still turns out to be faster and cheaper than continuing down the kludge path...


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## Daniel Holzman

It is a bit curious that the deck design books you read use techniques which are not acceptable under the IRC 2005 and later design standards. In my town, we use the IRC 2008 deck design standards, and the town gives you a copy of "Design for Code Acceptance" when you submit your deck plans. Here a couple of items off the IRC rules that your design violates:

1. All posts must be a minimum of 6x6. This allows them to be notched to accept beams. The only acceptable technique in IRC for attaching a beam to a post is to notch the post full width of the beam, or use a bracket designed to allow the beam to sit on top of the posts. Side by side attachment using bolts is specifically prohibited, as is attachment of a doubled beam to the post using bolts or lag screws.

2. Posts are not permitted to be installed directly on top of concrete. They are required to be installed using a standoff galvanized bracket. Similarly, beams cannot sit directly on a concrete pier. This is to prevent rot of the post due to contact with water on the top of the pier.

In your case, it may be impractical to redesign the setup, but you may want to check with your building inspector first, if you have a building inspector. It is possible to install a new standoff bracket in an existing concrete pier if the pier is sufficiently large, and you could then install 6x6 piers notched to accept the beams. Or perhaps there is no code in your jurisdiction, in which case you are presumably free to come up with an alternative approach.


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## CraigV

Daniel Holzman said:


> It is a bit curious that the deck design books you read use techniques which are not acceptable under the IRC 2005 and later design standards. In my town, we use the IRC 2008 deck design standards, and the town gives you a copy of "Design for Code Acceptance" when you submit your deck plans. Here a couple of items off the IRC rules that your design violates:
> 
> 1. All posts must be a minimum of 6x6. This allows them to be notched to accept beams. The only acceptable technique in IRC for attaching a beam to a post is to notch the post full width of the beam, or use a bracket designed to allow the beam to sit on top of the posts. Side by side attachment using bolts is specifically prohibited, as is attachment of a doubled beam to the post using bolts or lag screws.
> 
> 2. Posts are not permitted to be installed directly on top of concrete. They are required to be installed using a standoff galvanized bracket. Similarly, beams cannot sit directly on a concrete pier. This is to prevent rot of the post due to contact with water on the top of the pier.
> 
> In your case, it may be impractical to redesign the setup, but you may want to check with your building inspector first, if you have a building inspector. It is possible to install a new standoff bracket in an existing concrete pier if the pier is sufficiently large, and you could then install 6x6 piers notched to accept the beams. Or perhaps there is no code in your jurisdiction, in which case you are presumably free to come up with an alternative approach.


Point #1 is not entirely accurate. While bolts alone are prohibited, other hardware exists that is acceptable and economical. Simpson DJT14Z Deck Joist Ties are IRC 2009 compliant, and allow attachment of a 2x beam or joist to the side of a post. I have used them with inspection acceptance to augment existing installations for additional loads (converting a deck to a porch) as well as new construction for support beams. The load capacity is not enormous (1400lb maximum w/bolts, 1100 w/nails for floor support) but is adequate for many deck designs.


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