Cedar & Ground Contact - How does cedar hold up?

[Homer Faucett]

I just pulled a bunch of eastern red cedar fence posts out of the ground. They were over 30 years old and in generally good shape. Sapwood will decay, and is useless in ground contact (not much better than pine overall), but the heartwood performs better than PT, IME. Black locust and Osage Orange, however, will outperform both for ground contact.

[Carl Babel]

You can use Jasco wood preservative (Copper Clear) or equivalent to extend the life of your cedar posts. Soak the post ends in the preservative overnight and they will wick up a lot of preservative. They won't perform as well as pressure treated, but will probably last as long as the rest of the steps.

[Stew Hagerty]

Several people here have mentioned using treated lumber for ground contact and then using the cedar above ground. I thought I should point out that, according to the American Wood Protection Association (AWPA), there are different categories of treated lumber based on the level of treatment. Most of the treated lumber you will find at the big boxes will be one of the "UC3" categories (A or B) which is specified for above ground use. For anything that will be in direct contact with the ground you will want a "UC4" product (UC4-A for posts and such).

[Mel Fulks]

You are right on all points. Those materials are all good . They used to be easily obtained locally,even from the back yard. Now for most they are extremely expensive. For ground contact pressure treated is cheap and available ;and it can be ordered in a even stronger rating than the standard which will easily outlast most of us. Much of what people are going into debt to buy will be thrown away in a few years simply because they want to "upgrade". Hey,those granite counter tops won't last forever,gonna go with titanium next time. Whenever I see really well designed home appointments that were not inspired by a tv commercial people are happy with them. IMO Americans understand commodity values much better than they understand appropriate style and good design. Have to point out that those cedar posts only needed to last 30 years. I hope you can put them to good use!

[Doug Herzberg]

In Colorado, which is mostly arid except during the monsoon season, I generally replace Western Red Cedar fence posts after about 30 - 40 years because they rot in the ground. It happens much more quickly if they were set in concrete. Even PT set in concrete only lasts about 10 years around here. In Chicago, I would think the lifespan would be shorter.

Note that not all PT lumber is rated for ground contact these days. Read the little label stapled on the end. Good luck.

[Tom Hargrove]

Western Red Cedar would not be my choice for ground contact here in the Chicago area. I have a fence made from White Cedar posts and sections. Some of it is over 20 yrs old, and I began replacing the posts (direct contact with soil, no concrete sleeve) at about 15 years. It is still standing, but won't win a neighborhood beautification award. I replaced some of the fence in 2005 when we added on to the house, and it is becoming clear that the White Cedar in that portion of the fence will not last as long as the original portion. I built a couple of Adirondack chairs out of home center WRC in 2001 or 2002 that are outside all year round, either on the paver patio or in contact with soil/grass. I tossed one of them last year, and the other one will get the heave when I clean up the yard before winter hits. The stainless steel screws look like brand new, but the cedar at the bottom of the legs is going away, and the screws are impossible to keep tight in their holes. I put preservative on the bottom of the feet when I built the chairs, but Father Time is winning out despite my best efforts. The Deck Yard in St. Charles has better quality Cedar that you can find in home centers, but I understand they have or will soon go out of business. The pressure treated planter I put in during the early/mid 1990's is still holding together, but starting to get soft where the end grain is exposed. That's a project for next spring when my son is home from college. He is young, strong and follows orders . . ..

If cedar didn't rot, the woods in the western US would be full of downed trees that are as good as the live ones. WRC lasts longer than other woods, but it too goes away.

I hate PT wood, but for ground contact fences, decks, planters etc., that are outside 365 days a year, I think it is the only affordable option in the Windy City.

[Todd Burch]

Come to think of it - my fence is WRC. It has a terribly short lifespan. Fence pickets are 11 years old, no ground contact, and it's <been> shot.

[Stew Hagerty]

You are right on all points. Those materials are all good . They used to be easily obtained locally,even from the back yard. Now for most they are extremely expensive. For ground contact pressure treated is cheap and available ;and it can be ordered in a even stronger rating than the standard which will easily outlast most of us. Much of what people are going into debt to buy will be thrown away in a few years simply because they want to "upgrade". Hey,those granite counter tops won't last forever,gonna go with titanium next time. Whenever I see really well designed home appointments that were not inspired by a tv commercial people are happy with them. IMO Americans understand commodity values much better than they understand appropriate style and good design. Have to point out that those cedar posts only needed to last 30 years. I hope you can put them to good use!

When I was a GC I built several homes with permanent Wood Foundations. Back then we had CCA treated lumber and called it ".80" (versus the standard .40), while nowadays it would be UC4-C. Either way, a properly constructed wood foundation was expected to outlast the structure it supports.

[Peter Quinn]

Cedar will rot, no question there except how fast, and that depends on the piece of wood, the species, the local climate, site conditions. 3-15 years? plus or minus 2 years on either end IME! My approach, eliminate the ground contact. They make some handy little structural plastic stand-offs that screw into the bottom of the posts (they can take quite a load), or you can make one yourself from a piece of cedar colored trex, you can even use a metal one and paint it. Regrade around the post to eliminate topsoil contact, use a landscape feature to hold back the soil. Take charge of that site condition and reform it to suit your needs. Just don't put cedar on or in the ground. Its the wet/dry cycle that will rot it quick right at grade.

[scott vroom]

I use pressure treated for earth contact applications.

[Julie Moriarty]

I've already made the posts. If they end up rotting I can just replace them. I'll look into the Jasco treatment and keep as much of the dirt as I can away from the post bottom or cut them a little shorter so the dirt will never contact it. I have a 6x6 PT running horizontally under the stringers that sits mostly on an old concrete pad. I wanted to secure the cedar post bottom to this 6x6 and not so much the stringers. I'll need to do that soon, before winter rolls in, so we can safely use the new steps (which BTW are PT, as are the stringers).

Thanks everyone for your input. Now I know.

[Don Kingston]

has anyone tried wrapping post bottoms below grade with the sticky roofing paper that is supposed to be used on the first row of tar paper

[Tim Streagle]

I have put up pressure treated posts after dunking them in a five gallon bucket of roofing tar. Let it dry then plop 'em in the hole. They last a long time thataway.

[Jim Stewart]

Eastern Red Cedar has been used as fence posts for years. My neighbor has a farm fence that is probably older than thirty years and most of the posts are still fine. This fence is a cattle fence so posts get shear stress from the livestock when grass is in short supply. On the other hand Western Cedar is a wonderful wood that has been used for siding for years. It works great in that roll but not for ground contact. I suspect that Western Cedar is what you have if you got it at a lumber yard. I would change my design to allow moisture to drain. I am thinking of some of those metal plates that would hold the post slightly off of the ground to allow the wood to drain. You do not want to trap moisture at the base. I am located in SE Indiana.