Cedar posts for Arbor/Pergola - green or KD?

[warrierr]

Good morning,

I'm building an arbor/pergola for my wife and, I plan on using 4x4 or 6x6 cedar posts, 8-10' long (2' below sub grade). Lowe's sells these posts for a reasonable price ($45 a piece) but, they are green. I have not worked with green lumber before so I'm wondering how much warping green cedar may go through. Since these posts are coming in contact with the ground (and moisture), is it better for it to be green and come into equilibrium with outside moisture or is Kiln dried cedar better? KD cedar is a lot pricier and I would like to avoid it if possible. Any recommendations on sealants? Kindly do not recommend PT lumber. Thanks!

 

[Wyatt Co.]

Gosh, I was expecting someone to have some insight by now. But anywho...

I've never purchased green cedar already "finished" so I can't say what it's going to do as far as warping, bending, checking, etc. Personally, I'd be scared to death of spending $45 for a 4x4 post that I couldn't, or wouldn't, use after it dried out. But there again, all the cedar post (4x4, 4x6, 6x6, and 8x8) I use are kiln dried.

I can and will tell you to not construct anything with green wood. Holes get larger and fasteners become loose.

I buy all my cedar posts regardless of size from Horizon Forrest Products in Raleigh.

 

[scsmith42]

I own several wood kilns.... and I'd use them green.

Cedar does not need to be sterilized, it has a very low shrinkage ratio, and it air dries like a dream.

 

[Jeff]

The posts are listed as Western Red Cedar but dry or green may not be the main point for your concern. What's the rot resistance and/or termite resistance in ground contact (2' deep)? I don't know.

 

[Wyatt Co.]

I own several wood kilns.... and I'd use them green.

Cedar does not need to be sterilized, it has a very low shrinkage ratio, and it air dries like a dream.

True, but what about air dry deformation? An honest question.

 

[warrierr]

Thanks for the quick response! I assumed people on this forum would have had experience building arbors.

I wouldn't really want loose bolts with all the rafters above my head. From what I've read up, cedar is supposed to have low shrinkage and hygroscopic. Have you built any arbors with KD cedar? Do you directly bury the posts into the ground or grout to surface and bolt the posts in?

 

[warrierr]

The posts are listed as Western Red Cedar but dry or green may not be the main point for your concern. What's the rot resistance and/or termite resistance in ground contact (2' deep)? I don't know.

Thats great insight! However, I've heard cedar is naturally resistant to termites. An alternative would be to grout to surface and bolt the posts in place. Have you done one or the other? Have you had better luck with one or the other?

 

[warrierr]

I own several wood kilns.... and I'd use them green.

Cedar does not need to be sterilized, it has a very low shrinkage ratio, and it air dries like a dream.

Hi Scott, that's what I've heard too. Have you had clients who have experience building arbors?

 

[warrierr]

Gosh, I was expecting someone to have some insight by now. But anywho...

I've never purchased green cedar already "finished" so I can't say what it's going to do as far as warping, bending, checking, etc. Personally, I'd be scared to death of spending $45 for a 4x4 post that I couldn't, or wouldn't, use after it dried out. But there again, all the cedar post (4x4, 4x6, 6x6, and 8x8) I use are kiln dried.

I can and will tell you to not construct anything with green wood. Holes get larger and fasteners become loose.

I buy all my cedar posts regardless of size from Horizon Forrest Products in Raleigh.

Also, how much do their 4x4 or 6x6 posts sell for? I couldn't find a pricing sheet on their website and I suspect they might be closed. Thanks!

 

[CrealBilly]

Eastern Red Cedar is a great outdoor lumber. Only one issue I have with it. Your NC carpenter bee's love it also.

 

[Xlogger]

warrierr, give me a pm if you like. I keep a good bit of cedar here but as Scott said, it will be green and I've sold a good bit like that and never hear a complaint.

 

[Gotcha6]

My experience with local 'cedar' is what is known as Juniper (berries used for flavoring gin). The heart, or red portion of the wood withstands rot very well but the outer layer of white wood will decay rapidly as anyone who has used them for fence posts can attest. The commercially sold eastern and western red cedar refers to true cedar wood grown either east or west of the Sierra Divide in the western US respectively.

 

[Jeff]

Thats great insight! However, I've heard cedar is naturally resistant to termites. An alternative would be to grout to surface and bolt the posts in place. Have you done one or the other? Have you had better luck with one or the other?

I have no experience with pergola building or using untreated wood posts buried 2' in direct ground contact. There are galvanized post anchors like these which are plenty strong and the post bolt to them.

https://www.amazon.com/dp/B0026T7AZ...t=&hvlocphy=1021337&hvtargid=pla-343162221794

https://www.strongtie.com/postbases_capsandbases/category

 

[Jeff]

My experience with local 'cedar' is what is known as Juniper (berries used for flavoring gin). The heart, or red portion of the wood withstands rot very well but the outer layer of white wood will decay rapidly as anyone who has used them for fence posts can attest. The commercially sold eastern and western red cedar refers to true cedar wood grown either east or west of the Sierra Divide in the western US respectively.

My experience with local 'cedar' is what is known as Juniper (berries used for flavoring gin)

Eastern red cedar is a local cedar that's often referred to as juniper.

https://plants.ces.ncsu.edu/plants/all/juniperus-virginiana/

http://www.carolinanature.com/trees/juvi.html

Atlantic white cedar is sometimes called juniper but I don't think that's what you're referring too.

http://www.carolinanature.com/trees/chth.html

 

[warrierr]

Eastern Red Cedar is a great outdoor lumber. Only one issue I have with it. Your NC carpenter bee's love it also.

We're planning on growing muscadine grapes on the trellis so maybe they'll stick to just pollinating the grape flowers

 

[warrierr]

My experience with local 'cedar' is what is known as Juniper (berries used for flavoring gin). The heart, or red portion of the wood withstands rot very well but the outer layer of white wood will decay rapidly as anyone who has used them for fence posts can attest. The commercially sold eastern and western red cedar refers to true cedar wood grown either east or west of the Sierra Divide in the western US respectively.

Thank you Dennis! I'm a newb so, pardon the ignorance: what part of the ERC/WRC large fence posts (4x4 or larger) generally sawn from? Are they from all layers, rift sawn in perpendicular direction?

 

[sawman101]

I bought the property we live on 14 years ago. At that time there was the remains of a red cedar stump way out back. I worked on that stump for several years trying to make it disappear; burning by stacking firewood around it didn't do the trick. Chopping at it with a sharp axe got rid of all but some heartwood. Finally last year, I chopped enough off that the mower would pass over without a snag. That r.c. stump was the hardest, most resilient lumber I've come across, with the exception of petrified wood. IMHO, I'd use green cedar, preferably Eastern Red Cedar. That stuff is iron plated.

 

[Jeff]

I'm curious again. You've used the terms arbor and pergola to describe your muscadine grape support project and they're often used interchangeably.

Is your Pergola like this one?

https://www.walmart.com/ip/Backyard...75035&wl11=online&wl12=48923996&wl13=&veh=sem

Do you have a picture or sketch of what you're contemplating?

 

[Gotcha6]

"You've used the terms arbor and pergola to describe your muscadine grape support project and they're often used interchangeably."

I have often seen grape arbors, and they are usually built so that one could walk beneath and pick grapes, muscadines, scuppernongs, as the case may be, and usually constructed of 'Atlantic cedar' for durability. But to my mind a pergola was more of an architectural feature constructed of dressed lumber and not necessarily connected to aiding in the cultivation of anything. No doubt you could adapt it to being an arbor if you built it low enough to get to the fruit without a ladder.
I once read somewhere that the word 'pergola' was Italian for, "Let's waste some money."

 

[warrierr]

"You've used the terms arbor and pergola to describe your muscadine grape support project and they're often used interchangeably."

I have often seen grape arbors, and they are usually built so that one could walk beneath and pick grapes, muscadines, scuppernongs, as the case may be, and usually constructed of 'Atlantic cedar' for durability. But to my mind a pergola was more of an architectural feature constructed of dressed lumber and not necessarily connected to aiding in the cultivation of anything. No doubt you could adapt it to being an arbor if you built it low enough to get to the fruit without a ladder.
I once read somewhere that the word 'pergola' was Italian for, "Let's waste some money."

haha that's fair but I'd be a fool to let my wife know that �� Anyway , my plan is adapted from the southeast landscape design book and it's across between a pergola and arbor, if you go by strict definitions. Attached is a photo of the plan.