The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: Daburner87 on April 07, 2024, 08:55:49 PM

Title: Post Bases
Post by: Daburner87 on April 07, 2024, 08:55:49 PM
Where do you guys shop for things like 8x8 post bases? Locally I only have nominal 6x6 available.  Mostly Simpson Strong-Tie stuff, but nothing big for timber framing.  Any help appreciated.  

Title: Re: Post Bases
Post by: beenthere on April 07, 2024, 09:18:18 PM
I'd just go to my local welder and have them welded up to my specs. Do you have such a person available in the neighborhood? 
Title: Re: Post Bases
Post by: Don P on April 07, 2024, 10:17:29 PM
Post bases have been a sore subject here this week. $49 for a 6x6 simpson bolt down with a 1" standoff. We did a little better but he showed me a pic of the tag at Lowes $56. Hardware has gone nuts, or rather they've got you by... never mind. Check before assuming you can make it, on some work I can, on a residence I'd check. For 8x8, Simpson is at strongtie.com look up a CPT88Z (knife plate) or ABU88R (full 8x8) or ABU88Z (dressed)

Edit; I thought I had a pic of a shop made one from a job. This came with engineer sprinkles on it for the inspectors. The flat base with hooks was cast in the foundation, the knife plate with standoff was installed in the timber and then the bent was lifted, aligned, tacked and welded. I've made those with taller plates and drilled them at the same time as the post. I thought the end distance on this was too close.

(https://forestryforum.com/gallery/albums/userpics/10017/postbase~0.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=224326)
Title: Re: Post Bases
Post by: rusticretreater on April 07, 2024, 11:13:59 PM
So you drill the knife plate and the post together?  When you say the end distance was too close, did you mean the knife plate should have been taller and the securing hole a greater distance from the base?

How much does a fabrication like this cost?  Thx.
Title: Re: Post Bases
Post by: Brad_bb on April 08, 2024, 12:26:31 AM
SS knife plates (https://forestryforum.com/board/index.php?topic=112120.msg1761866#msg1761866)

Most have their own bases fabricated.  I don't know of anyone having and off the shelf one available. I prefer to drill the holes in the cured concrete and epoxy the anchors in.  Another option for an interior post is timberlinx hardware and a 1/4" thick 7x7 plexiglass plate on the bottom of the post to keep it separated from the concrete.
Title: Re: Post Bases
Post by: Daburner87 on April 08, 2024, 07:18:43 AM
Wow, yea those look really nice, and really expensive.   I really like the CPT88Z best.  Now I get a 10% discount at home depot so that seems the cheapest option, but how do the pins work? I would have thought this would be bolted on.  Never installed a knife plate before.
Title: Re: Post Bases
Post by: Don P on April 08, 2024, 07:57:54 AM
Use the knife plate itself (with the plastic standoff temporarily slid on) to mark the hole locations on the post. Then bolt the plate down and set the post on top, run a drill or drift in to locate the holes. Drive the dowel pins, set and cap the holes with a plug. You can use 1/2" bolts if desired, the strength is the same as the "dowel" in either case is in shear.

The reason for Simpson stuff is it has approvals and documented design strengths for the inspectors if they need that. Next route is a stamped design and a certified fabricator (paper trail).

For my homemade ones, drilling in place is not fun, step through bit sizes, but I know I'll hit the hole and "hook up" immediately. The big hole in the one above was for 1" pegs. Correctly the NDS will have minimum end distances.

For my shop (exempt) I made some hinged ones so we could tip it up. Once up I fully welded them to the cast in plate.
(https://forestryforum.com/gallery/albums/userpics/10017/postfoot.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=51267)

edit; this is a link to the CPTZ bases;
https://www.strongtie.com/specialtycollection_architecturalproductsgroup/cptz_base/p/cptz
Title: Re: Post Bases
Post by: Rhodemont on April 08, 2024, 07:17:45 PM
Check out Connext Post & Beam  https://ctpostandbeam.com/  
Couple more floor joists to saw and I will start my build using their hardware.
Title: Re: Post Bases
Post by: Brad_bb on April 09, 2024, 01:25:21 AM
To prep a post for a knife plate, you need to make a jig out of wood for your chainsaw so you can make a controlled plunge into the bottom of the post for the knife plate.  I don't have a picture of one.
Title: Re: Post Bases
Post by: rusticretreater on April 09, 2024, 12:26:42 PM
Connext sells three different slotters.  You might be able to fashion one from their pictures.  But the least expensive one is only $100.  Their videos are not very good.

https://ctpostandbeam.com/slotters (https://ctpostandbeam.com/slotters)

I also have a Prazi beam cutter which is a saw head you put on a circular saw. Haven't used it yet, but I hope its my solution.

https://www.praziusa.com/12-beam-cutter-model-pr-2700/ (https://www.praziusa.com/12-beam-cutter-model-pr-2700/)
Title: Re: Post Bases
Post by: Daburner87 on April 10, 2024, 04:31:09 PM
Well this is weird.  I went into Home Depot for a few quick items as I'm building a deck around a pool, and I walked past the clearance section end cap and they had a fire sale on OWT products which included 6x6 post bases, and other heavy timber related braces, and hardware.  Long story short I spent $350 on stuff, and it allowed my military discount.    So the post bases are normally $43 I got them for $9, same for the post to beam connectors.  I realize I might end up returning some of this stuff, but these are pretty heavy duty, and have uses other than just what intended.  Like these...

https://www.homedepot.com/p/OWT-Ornamental-Wood-Ties-Laredo-Sunset-4-in-x-12-Gauge-Galv-St-Rafter-Clip-Angle-Brackets-2-Pack-46618-1/313033419