Deck post to beam connection ?

[Marctrees]

Building a 10 x 20 deck... dock at waters edge.

4x6 posts, three rows of 5 each.

Going to put 2x8 beams under joists.

Want to talk about connection of beams to posts.

Sure ... best to cut a shallow rabbet to act as a ledger, then throughbolt or screw to post.

The rabbet cutting is a major PIA over water.

Want to use GK RS 3/8 x 5 to w/o rabbet attach 1 1/2" 2x8 beams to the 4" thickness of the posts.

Posts will continue up to railing height around perimiter, and be flush cut at top of beams in middle row of deck.

Propose slapping "2x8" joist against beam, NO rabbet ledge, and four GRK RSS 3/8 x 5" per connection.

Thoughts ?

Marc

 

[mmb617]

I'd do it. I built a deck using that method of attaching the beams to the posts 32 years ago. It's still up and I haven't seen any problems so far.

 

[CraigStu]

I would too, but will it pass inspection? We don't live near the water any more but our home deck built March this year code required the beams to sit on rabbits.

 

[aandpdan]

Won't pass current code.

Here's a link for you: https://www.awc.org/codes-standards/publications/dca6

 

[Marctrees]

Actually we are very rural w no inspections.

Overall this thing will be built sturdier than 99% of others around here.

Marc

 

[mike93lx]

Actually we are very rural w no inspections.

Overall this thing will be built sturdier than 99% of others around here.

Marc

If that is your standard, then go for it. Why ask?

 

[Marctrees]

It is not my "Standard"

Usually I cut rabbets.

Would rather not in this case.


Asking to get experienced answers, not snarky comments.

It's called a "Forum" Mike, where ideas are discussed.

Look around - I am pretty sure the majority of wood docks are not rabbeted.

Marc

 

[manwithtools]

Take a look at LedgerLOK fasteners. I think it may be a challenge to meet code without notches for the beam members or steel connectors (i.e. Simpson).

 

[mike93lx]

Nevermind

 

[Git]

It sounds like your causing yourself some problems because you want to use the posts also for the handrail?

Why not use solid beams on top of the posts (cut down the posts to the correct height)

The first pic is from Austin - remember, this is 'minimum' in their mind
http://www.ci.austin.mn.us/Engineering/Building Dept Handouts/Decks Porches.pdf

Then you can do something like this for the handrail posts

 

[rburke65]

No inspection....do what ya want.

 

[Bretny]

Use 6x6 for the posts and notch them out for the beam. 4x6 dosnt leave much room for the notch and if you dont notch your making your hardware hold the whole deck.

 

[ford33]

If I understand your water dock post beam connection correctly, the only thing bearing the entire weight of the dock joists against the post is the GRK RSS 3/8 x 5" metal fasteners. Material is listed as stainless steel. Cost is $0.84 each on Amazon. I like these fasteners and have used them on my deck.

You can do what you want but you should think very long term. Docks rarely get needed maintenance and are not replaced until they are falling apart.

Think several decades. The reason the beam sits in a notch on the post is so the post can still carry the weight if anything moves significantly or the fasteners fail over time. Movement could be caused by a boat hitting the dock, too many people on the dock at one time or the beam end or post weakens due to poor preservative treatment or insects. You may experience higher than planned loading near the end of life of the dock. If one connection fails the others may not have sufficient strength to carry the remaining load and then everyone falls into the water.

Perhaps your dock will be fine for the first 20 years but the next 20 years maybe not. Since no building code enforcement is done, you need to learn how to do it right yourself so you can sleep at night. learn from the experience of others. When a dock fails, it always makes the evening news.

 

[theoldwizard1]

Want to talk about connection of beams to posts.

Sure ... best to cut a shallow rabbet to act as a ledger, then throughbolt or screw to post.

The rabbet cutting is a major PIA over water.

Make a "built up" post ! 3 - 2x6 PT screwed together (use hot dipped galvanized or stainless fasteners). Leave the one short. There is your rabbet !

 

[Bretny]

Ford33. Your not getting 3/8 stainless bolts 5in long for 84cents.

 

[MoonRise]

Deck post minimum size required is 6x6.

(fine print note: with certain "tributary area" and deck post height limitations, 4x4 posts are -sometimes- acceptable. Most of the time though, 6x6 or bigger posts are required. Your proposed deck size can not use 4x4 posts any higher than 2 feet no matter what. Meaning pretty much that 6x6 or bigger posts are required for your proposed deck.)

Beam connection to the posts is REQUIRED to be fully bearing on a notched 'ledge' on the post top OR with an APPROVED Post-to-Beam Post Cap attachment.

For the beam resting on the notched post, the required fasteners are 1/2" diameter through bolts with washers under the bolt head and under the nut.

Built-up beam made from triple 2x lumber (or anything bigger) is required to use the APPROVED post cap attachment.

Minimum beam thickness is doubled 2x lumber (Or 3" or 4" lumber). No slapping a single 2x8 onto the post and calling it a 'beam'.

Read the linked DCA6 document.

See Simpson for all sorts of approved hangers and brackets.

Don't want to notch the posts for the beams to sit on? Use the approved Simpson Post-to-Beam Post Cap attachment bracket on the minimum 6x6 posts.

(because of a bunch of 'recent' catastrophic deck failures with serious injuries and fatalities, deck construction code requirements became much more strict. Recent being around 2010 or so, DCA6 last/latest revision is dated 2015 and based on the 2012 IRC.)

Even without having to pass 'inspection', if you build it and it fails you WILL be raked over the coals and through the courts for not following 'best practices'. Where 'best practices' pretty much means current (at the time of build at least) Codes.