×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

WOOD POST EMBEDDED IN CONCRETE

WOOD POST EMBEDDED IN CONCRETE

WOOD POST EMBEDDED IN CONCRETE

(OP)
I have to design a 10’ tall (cantilever) privacy fence and was wondering how to fix an 8x8 timber post to a 24" diameter concrete pier.  What else can you do other than embedding the post in the pier?  This structure is temporary only needing to withstand 5-yrs of service and I would like to keep this economical (residential feel).  Does anyone have any suggestions?

TIA

RE: WOOD POST EMBEDDED IN CONCRETE

Embedding the post seems to be the best option, otherwise you will have to fabricate some base plate detail to attach to the pier that will house your post. Seems like a bit of over-kill to me. Embed the thing. If the client wants rid of it in 5 years, he can chop the top of it off and put a light screed over the top to mask the evidence.

RE: WOOD POST EMBEDDED IN CONCRETE

Typically we spike the post to lock it in the base.  Slope the top away from the post a few degrees to keep water away.  Keep the post bottom a few inches away from the dirt.  For a 10" privacy fence, 8x8 w 24" pier seems an over kill!

RE: WOOD POST EMBEDDED IN CONCRETE

The post will expand as it absorbs moisture and crack the pier. It may be a good idea to put in a #3 square or hoop tie.  

RE: WOOD POST EMBEDDED IN CONCRETE

My neighbor embedded fence posts in concrete and the wood rotted away within 2 years.  Best stick with pressure treated or get a good recomendation from both the wood and concrete people.

RE: WOOD POST EMBEDDED IN CONCRETE

Using an embedded HSS sleeve may be considered.

RE: WOOD POST EMBEDDED IN CONCRETE

For fence posts I would dig the post hole, set the post and fill with gravel. Once compacted it functions every bit as well as cracked unreinforced concrete in this application. It also has the advantage of being free draining. It would also make removal of posts easier if required as digging out the gravel is easier than concrete. I would also go a little deeper than 24", but I have frost to consider as well as pretty high wind.

Rik

RE: WOOD POST EMBEDDED IN CONCRETE

the 24" was Dia

RE: WOOD POST EMBEDDED IN CONCRETE


Oops, Your right Boo1. Thanks for the correction. I do agree with you that 24" diameter seems excessive.

Rik

RE: WOOD POST EMBEDDED IN CONCRETE

never embed a wood post in concrete.  Most codes do not allow this anyhow.  I wouldn't recommend burying below ground either.  Use the concrete base and a steel bracket anchored in the concrete.  This is a fairly standard item available at Home Depot.

RE: WOOD POST EMBEDDED IN CONCRETE

Like cvg, I would avoid embedding wood posts or columns in concrete.

If you must, ensure that you use pressure preservative treated wood.

RE: WOOD POST EMBEDDED IN CONCRETE

(OP)
Wow...quite a range of answers here.  I truly appreciate the responses but it just reaffirms my original thought of "I don't know".  I guess it depends on how you like to mitigate your losses here.  To clarify the design an 8x8x10'-0" post 8'-0" O/C is required by design for douglas fir south No. 2 for 14psf wind pressure and a 2' diameter pier is also required based upon 200pcf passive pressure per IBC 1807.2.9    

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources