Cedar & Ground Contact - How does cedar hold up?

[Julie Moriarty]

I made some modifications on our back deck and had to redo the railings. I decided to do it in cedar. While cutting the posts that will fit at the bottom of the steps I realized as much as 2" of the bottom will be in contact with the ground. The bottom of the post would be in contact with paver base and the side with topsoil.

I've used PT lumber specifically rated for ground contact without any problems, but cedar? I'm worried it will rot, even with so little ground contact. I've thought about laying some small cobblestone around it. Cobble would blend in with the pavers. But over time I know dirt would silt in.

Is there a way I can use these posts without worrying about rot? They are already cut and routed and nicely match the ones at the deck level. Or do I need to put PT posts in?

[Peter Aeschliman]

I had some cedar siding touching dirt for a winter one year... had to be replaced the next summer. Cedar does have good weather resistance, but not as good as pressure treated lumber. So I would avoid the situation you describe if you can. It may last you a few years, but i assume you'd prefer it to last longer than that!

PS- I live in the Seattle area where there's lots of precipitation in the winter and not much snow. Your experience in Chicago will probably vary!

[Mel Fulks]

Don't know whether you are referring to western red cedar or Virginia cedar .Niether of which is a true cedar. The trouble with these things is partly the way the stuff is graded. Most of the grade specs say that sapwood is not a defect,even though it is totally unfit to be used outside unless treated. Never mind that most buy it for exterior use. Same thing with Douglas Fir,which most botanists say is not a true fir. See a trend here? I rip off all sapwood and discard it, have been reprimanded at times. But I will not use it. You could put pressure treated in ground and cover it above ground with a shimmed out architectural shell.

[Mel Fulks]

I see now the posts are all done .Think I would trim them about 3 inches and polyurethane glue pt blocks on them and stain the bottoms a little on the dark side , better too dark at bottom than too light. Crude but effective .

[Erik Loza]

Not sure which species of cedar we get here in TX (western, I assume? I think that's the common one..). In any case, I would definitely NOT use it for ground contact. Green-treat would be my choice. As others mentioned, you could trim out your posts with cedar or whatever, my experience is that when it cedar is in contact with dirt, it deteriorates surprisingly quickly.

Best of luck with your project,

Erik Loza
Minimax USA

[Kevin Bourque]

Cedar will not hold up to ground contact exposure. I don't even like to use it in shady locations above ground. It's a highly overrated exterior wood IMO.

[Todd Burch]

These discussions are always so interesting! Here is Texas we have eastern red cedar (not western). There are houses around (in the country) that have sat on cedar "stumps" used as piers for over 100 years. The one house foundation I am picturing in my mind right now (Chappell Hill, Texas) is pretty wavy, but it's not because the cedar is rotting, but because the ground has moved quicker than the cedar has deteriorated over the last 100 years.

[Mel Fulks]

Again,it is helpful to know what we are calling cedar. There are lots of cites of the juniper we call cedar lasting a very long time in contact with the ground and under it. Some are grave related ,coffins and markers.But it's old growth heart. A good source for rating woods and differentiating among sap ,heart , and old growth heart is the book WOOD AS AN ENGINEERING MATERIAL. Your tax dollars at work.

[Gary Herrmann]

I've got a cedar fence. Posts are cedar. 4 years old and it's holding up fine.

[Philip Berman]

Funny, I just posted about using pressure-treated.

I purchased a fence from Walpole Woodworkers in Massachusetts about 12 years ago. They were very very expensive, and when I questioned why, was told "it's white cedar, it'll last forever". I bought the fence(and the explanation, clearly). This year I contacted them when half the fence began leaning forward at a 30degree angle and having determined that the fence posts(6x6's) had rotted. Everything on the fence was white cedar. First words out of their mouths? "Nothing lasts forever, you need a new fence". Doing it myself this time since their 'forever fence' is now over $500 per foot. Live and learn. Oh, and the 'forever fence' doesn't actually come with a written warranty, but it'll last forever 'cause the salesmen said so, hence the cost. Right.

Phil

[David Helm]

Western Red Cedar, while somewhat weather resistant (old growth, heart wood only), is not for ground contact. It will rot within a few years. Way too expensive for short life.

[Brent DenHartog]

Another "no" vote from me. I had a porch railing and a mailbox post in ground contact both made from whatever Menards in the midwest calls cedar. They both rotted in <10 years.

I think cedar probably works ok as an outside wood, but once you put it in continuous contact with wet dirt it is destined to rot. Maybe if you want to improve your odds you could surround it with pea gravel or something else that would drain.

Just to explain how a porch railing was in ground contact: The posts for the porch railing had a half lap like notch cut in the bottom where the notch sat on concrete and the rest extended into the ground and was bolted into the side of the concrete. Then they back filled up to the level of the concrete.

[Todd Burch]

I just happened to be driving through Chappell Hill today - and swung a U-Turn to take a picture of the building I referred to earlier.

[Erik Loza]

I just happened to be driving through Chappell Hill today - and swung a U-Turn to take a picture of the building I referred to earlier.

Hi Todd,

In your photo, those posts look to me like Juniper rather than cedar. Like, the local (at least to us Texans...) "cedar" that is actually a species of juniper. The juniper seems to be a lot more durable stuff than true cedar (I'm originally from California and used to Cedar being tall, straight trees, not unlike Ponderosa Pine, for example). Any thoughts on that?

Erik Loza
Minimax USA

[Todd Burch]

I call it red cedar, same as eastern red cedar. This site calls eastern red cedar and juniper the same tree:
http://forestry.about.com/od/treeidentification/tp/tree_key_id_cedar.htm

[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.