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Girder post

ICE

ICE

Oh Well
Joined
Jun 23, 2011
Messages
12,914
Location
California
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There is no connection between the wood sleeper and the concrete.

The construction isn't engineered.

What does the IRC say about that? I would appreciate a code section

Thanks
 
Don't have a code section since I am at home but i don't see how that is any different from a girder resting directly on the pier which in Virginia would not need a mechanical connection. Of course we have no seismic so I don't know how that would change things for you in Cali. It looks like it is close enough to the ground to require pressure treated joists and girders and posts though.
 
In cali, I am sure that the seismic provision of the code will address this issue.

SECTION R407

COLUMNS

R407.1 Wood column protection. Wood columns shall be

protected against decay as set forth in Section R319.

R407.2 Steel column protection. All surfaces (inside and outside)

of steel columns shall be given a shop coat of

rust-inhibitive paint, except for corrosion-resistant steel and

steel treated with coatings to provide corrosion resistance.

R407.3 Structural requirements. The columns shall be

restrained to prevent lateral displacement at the bottom end.

Wood columns shall not be less in nominal size than 4 inches by

4 inches (102 mm by 102 mm) and steel columns shall not be

less than 3-inch-diameter (76 mm) standard pipe or approved

equivalent.

Exception: In Seismic Design Categories A, B and C columns

no more than 48 inches (1219 mm) in height on a pier or footing are exempt from the bottom end lateral displacement

requirement within underfloor areas enclosed by a

continuous foundation.
 
Last edited by a moderator:
I knew that there needs to be a connection. What I didn't know was what the IRC required. As it turns out, the IRC isn't much help because all it says is "restrained". A post base? An anchor bolt? A shot pin? PL400?
 
Ice 502.9 requires positive connection so I guess your call as to what a positive connection shall be for uplift, and lateral displacement.
 
The IRC breaks the seismic D zone into 3 different classifications

0.50g < SDS £ 0.67g D0

0.67g < SDS £ 0.83g D1

0.83g < SDS £ 1.17g D2

R502.9 Fastening.

Floor framing shall be nailed in accordance with Table R602.3(1). Where posts and beam or girder construction is used to support floor framing, positive connections shall be provided to ensure against uplift and lateral displacement.

Is this an Irregular building?

R301.2.2.2.5 Irregular buildings.

Prescriptive construction as regulated by this code shall not be used for irregular structures located in Seismic Design Categories C, D0, D1 and D2. Irregular portions of structures shall be designed in accordance with accepted engineering practice to the extent the irregular features affect the performance of the remaining structural system. When the forces associated with the irregularity are resisted by a structural system designed in accordance with accepted engineering practice, design of the remainder of the building shall be permitted using the provisions of this code. A building or portion of a building shall be considered to be irregular when one or more of the following conditions occur:..........
 
ddddddddddddddddddddddddd - lightful Shirley!

The AHJ can make a determination of what the restraint requirements can be,

or they can require a structural engineer to calculate it!

.
 
As an AHJ, i made the determination that the minimum means of attachment in seismic design catagory D can be accomplished with velcro!
 
Ice,

I would approve a clip and anchor that is equal to the positive connections above the the post.
 
Rider Rick said:
Ice,I would approve a clip and anchor that is equal to the positive connections above the the post.
Click to expand...
That may work on this example but the seismic loads would be greater on the bottom as the length of the post increases
 
Section 404.1.9.2 of the 2012 IRC will require the girders and sill plates to be anchored to the piers.
 
R301.1 Design.

Buildings and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures shall result in a system that provides a complete load path capable of transferring all loads from their point of origin through the load-resisting elements to the foundation.
 
Per local amendment here we don't allow wood columns in crawls. That being said I was fine with it in my last jurisdiction but I did require restraint. I allowed a connection such as cut nails on the treated plate (though I much preferred a tapcon) and toenails on the post to plate (again I preferred a mechanical connector) If it was a post directly on the pier I required a mechanical connector. I saw the reason for the requirement as this; if the floor system moves (shrinkage or expansion?) or the pier settles and if the post is not connected it could possibly swing or be knocked out of plumb or even off of alignment with the pier, compromising the structure. I didn't really see the connector as needing to be particularly strong just capable of keeping the post aligned..............But what do I know, I wasn't 100% sure pex was plastic?
 
i am not sure about approving the connection in ice's photo. I normally approve a precast pier block with a piece of pressure treated 2x6 installed at the time of precasting. I have no problem approving a toenailed connection from the post to said precast pier until someone can point out where it is specifically prohibited in the code in seismic design category D, not seismic zones anymore.
 
pwood said:
i am not sure about approving the connection in ice's photo. I normally approve a precast pier block with a piece of pressure treated 2x6 installed at the time of precasting. I have no problem approving a toenailed connection from the post to said precast pier until someone can point out where it is specifically prohibited in the code in seismic design category D, not seismic zones anymore.
Click to expand...
What about the pier to concrete footing connection, placed directly on concrete? I have in the past bumped a pier with a long joist and popped it easily from the concrete footing.

In general I see the precast pier with wood block set in concrete as inferior and unable to meet the a liberal interpretation of the those stated codes. It seems to me that if you are going to enforce the lateral displacement requirement, it has to be enforced into the undisturbed ground.

Brent.
 
You might look at section 407 which as an exception for this kind of installation R407.3 Structural requirements. The columns shall be

restrained to prevent lateral displacement at the bottom end.

Wood columns shall not be less in nominal size than 4 inches by

4 inches (102 mm by 102 mm) and steel columns shall not be

less than 3-inch-diameter (76 mm) standard pipe or approved

equivalent.

Exception: In Seismic Design Categories A, B and C columns

no more than 48 inches (1219 mm) in height on a pier

or footing are exempt from the bottom end lateral displacement

requirement within underfloor areas enclosed by a

continuous foundation.
 
MASSDRIVER said:
What about the pier to concrete footing connection, placed directly on concrete? I have in the past bumped a pier with a long joist and popped it easily from the concrete footing.In general I see the precast pier with wood block set in concrete as inferior and unable to meet the a liberal interpretation of the those stated codes. It seems to me that if you are going to enforce the lateral displacement requirement, it has to be enforced into the undisturbed ground.

Brent.
Click to expand...
the pier blocks are embedded (wet set) into the concrete footings.
 
pwood said:
the pier blocks are embedded (wet set) into the concrete footings.
Click to expand...
I'm wondering what that means though. There is no connection. Does wet-set mean sitting on top of wet concrete, slumped into it, concrete moved up the pier to encase the bottom? How much embedment?

My point is, we have been using them forever, and sometimes there seems to be an emphasis on hardware connection from girder to post to block, but what use is it if you stop there? The system needs to be complete, otherwise simple toenailing of all members is just as adequate as full hardware connection, unless we pour a pier with wet-set PB's in it.

Brent.
 
MASSDRIVER said:
I'm wondering what that means though. There is no connection. Does wet-set mean sitting on top of wet concrete, slumped into it, concrete moved up the pier to encase the bottom? How much embedment?My point is, we have been using them forever, and sometimes there seems to be an emphasis on hardware connection from girder to post to block, but what use is it if you stop there? The system needs to be complete, otherwise simple toenailing of all members is just as adequate as full hardware connection, unless we pour a pier with wet-set PB's in it.

Brent.
Click to expand...
dig an isolated footing hole, say 2sq. ft. wide, by 12" deep and toss in some rebar pieces if you please. call a ready mix truck or hand mix some concrete and deposit said concrete in the pre dug isolated footing hole with the steel that might or might not be in it. Then you pick up a premanufactured pier block that has a piece of pressure treated wood factory installed on it and set it in the aforementioned footing hole that has been filled with the aforementioned still wet concrete. push in a downward direction on the aforementioned premanufactured pier block until the bottom of the block is about three inches below the top of the aforementioned concrete which has been placed in the previuosly mentioned footing hole. take a torpedo level and place it on top of the previously mentioned pier block and apply gentle pressure on the said block until the little air bubble on the little level is visible. that's good nuff for now. Go enjoy a cold one and return the next day and toe nail a post with 16D galvanized nails (6-10 odda do) to the aforementioned assembly. The structure will be habitable in no time. Show progress to the perspective owners and tell them they better start packing. Is it all clear now?
 
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