Embedded Wood Post Detail 2

[T_Bat]

Hey everyone,

I've got another wood building I'm looking at with a large covered porch/patio. The arch wants to avoid knee braces so I'm looking into doing an embedded wood post. Obviously some people say "no way - you are asking for trouble" but it seems this type of detail has been used with success in the past. I'm proposing to embed the posts (or as many as is economical and works for design). I've attached a sketch and an overall. Normal wind speed here and SDC C. My main questions are:

1. Is there a special preservative treatment I need to specify or does the typical stuff work here?
2. Any benefit of coating with a mastic coating? maybe extend up the post a bit (they will be wrapped)?
3. Seems I need to make sure the end that's embedded is treated (no cut ends down there).

I know there have been other threads on this topic but they seems to be for utility type buildings or smaller structures (not that this is huge or anything). Any comments on the detail are appreciated.

Thanks!

 

[T_Bat]

Great info SRE! Thanks for taking the time to lay that out.

CAB - that's why I proposed alternate sketch #2 above. I assume you are describing a mix of the two sketches - basically stop the concrete pier short and let the SOG pour up to the posts. I think that's a better, 3rd, alternative.

 

[NorthCivil]

All the folks cheering this design must live in the sahara desert! There is no way I would go anywhere near a detail like this, even in the dry-desert areas that I have practiced.

It is true that treated timber foundations are used in the canadian prairies. the difference is, these foundations mainly take compressive forces, and if the timber rots and begins to crush, only results in settlement (non life threatening)

This post will take repeated lateral loading, bending forces. It will rot and be ready to collapse within 30 years. Hopefully at that point there will be a conscious building operator ready to replace it.

All of this because some architect isnt a fan of knee-braces.