Recommendation For 6x6 Post Bracket (Using 3 ply laminated columns)

[airman89]

Well I made a stupid mistake. Originally I was going to use 6x6 solid posts all the way around but switched to 3 ply laminated columns for the gable sides. The brackets were wet set brackets and are nice and firm…. I thought about cutting them out but that’s a pretty $800-$900 to toss in the trash can.

I was looking for a pressure treated plywood to cut some spacers but can only find above ground treated. I have to abide by building codes too. Are there any recommendations on a 1/2” thick material that is code compliant?

Just to reinforce the situation, the 3 ply columns are 1” shy of fitting in the 6x6 brackets snug.

 

[jack stand]

Confused, the whole point of these brackets is to  not have any ground contact of the wood post. (use regular pt plywood)
Secondly 3 ply's should be 4 1/2" +/- , guessing that you have a 5 1/2" space in your brackets. There's nothing wrong with a 5/4 (+/-1" net) pt deck board on either side of your 3 ply post just to snug it to the bracket. This, providing that it's all above grade.

 

[airman89]

Confused, the whole point of these brackets is to  not have any ground contact of the wood post. (use regular pt plywood)
Secondly 3 ply's should be 4 1/2" +/- , guessing that you have a 5 1/2" space in your brackets. There's nothing wrong with a 5/4 (+/-1" net) pt deck board on either side of your 3 ply post just to snug it to the bracket. This, providing that it's all above grade.

Well this is great news. What I was reading (probably misunderstanding) was that any wood that comes within 6” or the ground or concrete foundation must be treated for ground contact. I probably read it a bit wrong it sounds like.

Well a pt deck board would really simplify things, I’ll be grabbing a few soon. Thanks for the fast, excellent info.

 

[billconner]

I'd think about cement board. Compressive strength way beyond wood. No water issues. Reasonable cost.

 

[jar944]

Why not just go back to 6x6s?

 

[airman89]

I'd think about cement board. Compressive strength way beyond wood. No water issues. Reasonable cost.

That’s a great idea, I didn’t think about that.

Why not just go back to 6x6s?

I would but the reason I switched to the laminated columns is because I needed 22’, 24’ and 26’ on the gable ends and the posts that I see over 18/20’ in length are almost impossible to find straight and twist free.

 

[Firebrick43]

I'd think about cement board. Compressive strength way beyond wood. No water issues. Reasonable cost.

I don’t know what cement board your using but every brand I have used doesn’t have that much compressive strength and when it fails it just breaks up and falls apart nor is it structural in any way.


I second @jack stand pt deck board or take some short sections of treated 2x6 to someone with a band saw that is capable of resawing them to the thickness you want.

 

[jack stand]

I'd put common KD lumber (painted) in this "splash area" before any so called "cement" product.
Read the fine print and warranty documents. It's basically not waterproof and like wood, it requires paint to protect it, just 10x more expensive.

 

[billconner]

I don’t know what cement board your using but every brand I have used doesn’t have that much compressive strength

It's basically concrete so it has a lot of compressive strength. Durock says 1250 psi. Pine - perpendicular to the grain as it would be here - is in the 500-600 psi range.

(No, not water proof, in that water will pass through it, but like concrete, no problems being in water. From their site: "For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof." From others "not affected by water".)

I wasn't going to suggest it because it claims to be non-structural, but PVC trim boards can be near a 1000 psi.

https://www.jlconline.com/how-to/framing/compressive-strength-of-cellular-pvc-trim_o

 

[CTyankee]

Agree with the PT block to fill the bracket. Pitch the top end to shed any water.

 

[Wolley]

Might need to use half inch on each side to maintain your spacing depending on how big your building is and what you have for lumber

 

[NUTTSGT]

Might need to use half inch on each side to maintain your spacing depending on how big your building is and what you have for lumber

I'm not sure what the cost difference would be but there's an option of 4 ply posts and ripping e required distance off each side.

However, before you get too far into it, I would talk to the AHJ, since you are trying to be code compliant..... getting inspected ?

 

[KenC]

Tile backing Cement Board or Jame Hardie type siding board? I think guys are talking about two different things. Tile board, OK IMO, fiber cement board not so much.

 

[billconner]

Durock or equal. Or Durock for exterior or equals. One is called skirt board, but I have not checked their data sheets for compression. Either should work here if inside. Not Hardiboard or other cementious siding.

 

[jack stand]

Yes I thought that the "hardy" type product was being suggested.
As far as any layout concerns - 1/2" off center of the bracket in reality (pole building framing) is meaningless particularly on an end wall that would typically be a non bearing wall.

 

[Hank11]

Absolutely no cement board product for this use. Totally unsuitable.

Since this is getting inspected, call the manufacturer of the brackets to see if you can get some documented advice from them.

If it was mine I’d think about epoxying some treated kiln dried material spacers on the inside and carrying them the length of the laminated posts. Glued and screwed.

Other obvious solution is to talk to the laminated beam supplier and see if they have or will make you posts to fit. This would be best of all.

 

[PoorUB]

Do you have a local company that does galvanizing? Have some 1/2" plate cut up to match the brackets, have them galvanized, and use them for spacers.

I would not use Durarock, or any other cemet board . No structural strength.

 

[mike93lx]

Do you have a local company that does galvanizing? Have some 1/2" plate cut up to match the brackets, have them galvanized, and use them for spacers.

I would not use Durarock, or any other cemet board . No structural strength.

Could order them from send cut send and just paint, too

 

[KenC]

IMO, this is just a spacer, no structural properties needed, except not to crush under fastener load. I'd grab some PVC boards at HD/Lowes of the correct thickness and cut some spacers. First thing though, I'd speak with the inspector to be sure his view matched mine.

 

[billconner]

IMO, this is just a spacer, no structural properties needed, except not to crush under fastener load. I'd grab some PVC boards at HD/Lowes of the correct thickness and cut some spacers. First thing though, I'd speak with the inspector to be sure his view matched mine.

I agree it is just a spacer and only in compression. PVC is not a bad idea but some brands have less compressive strength than wood. I'd recommend looking at data sheets to or one over a 1000 psi compressive strength.

Steel would be fine - just the most expensive choice by far.

 

[rayra]

I'd think about cement board. Compressive strength way beyond wood. No water issues. Reasonable cost.

Maybe you are thinking of hardiboard planks. 'Cement board' also describes the crumbly **** with fiber mesh that is used as a tile backer, which has ne real strength at all, except as a base for good adhesion of tile mastics.

OP just needs to make some hardwood shims so he can thru-bolt his lam posts into the 6x6 post brackets. OP is both overthinking it AND crafting his build from a position of ignorance about materials and best practices.

/and you'll want to make sure of the alignment of your post brackets and glue-lam placements with regard to the exterior facing of your building. It's another place to make mistakes and / or correct other mistakes.

 

[billconner]

I was suggesting backer board which has much more strength in compression than wood, and these shims are only in compression.

 

[Hank11]

I was suggesting backer board which has much more strength in compression than wood, and these shims are only in compression.

It’ll fail before you get all the holes drilled.

 

[billconner]

Where do you buy your backer board?

 

[Jakemedic]

When the Amish built my post frame shop, they used plywood with the laminated beams. I didn’t see any issue with that personally. the posts were located on my poured foundation walls, so no issue with wetness.

 

[AMXJohn]

Use 4 each- 2x6 for your posts, they will end up 5.5" x 6". Then notch the outer 2 boards to make the thickness of the bracket. Installed in the correct orientation, you will maintain the correct post depth interior to exterior (5.5") and have 6" post width within the wall which will not matter one bit. Using this method, you will be able to use all ground contact PT. Only downside is that you will have to buy a few more 2x6.

 

[Firebrick43]

Where do you buy your backer board?

I have used USG and hardie backer board and they are both the same way. Drop it and it cracks/crumble from 2-3’. Put a screw to close to the corner and it cracks. Hears Joy Beher senseless ramblings and it cracks.