Plastic Post Sleeves

[John_C]

One of the new members posted a question about these plastic sleeves

http://www.plasti-sleeve.com/plastisleeve.html

How can these extend the life of the post/piers?  I can't see them doing anything but trapping moisture against the wood.  The plastic bottom guarantees that any moisture that gets in there will stay in there.  Even IF they were applied and fitted like heat shrink tubing the capillary action of the wood fibers would still wick some moisture in there. 

I started a new thread because I didn't want the new guy to think I was picking on him....  I'm picking on the product.  How do they do anything beneficial???

[MountainDon]

John  C that kicked my skeptical bone as well. I see the theory but do wonder about the real world experience. If the upper end was up in a dry area that's never supposed to get wet you would think that everything should be okay. But to me there are so many 'what if's' that could happen I'd probably worry more about what's going on down in the ground that I'd worry about any possible so far unknown bad side effects with the ACQ wood.

If you recall Glenn had wrapped the bottom ends of some timbers in the Underground Cabin with plastic bags. After a few years he wondered why a door wasn't hanging right. IIRC, that was the symptom. He found rot. Sure it may not be fair to compare the water tightness of some wrapped plastic to these sleeves. But IF water gets in the sleeve it will be a problem. Or should I say WHEN water gets in there.

I don't trust to luck... done that in the past and got burned.

OMMV

[John_C]

My porch sits on PT 6x6 that have been in the ground for 20 years.  Last fall when there was a thread about posts rotting so I poked around them and only 1 out of 18 shows any deterioration.  It'll need to be replaced in 20 years or so.  I don't have many 20 year old plastic things that are in such good shape. 

If I was concerned about posts I'd spray them every year or so with a borate solution.  For that matter throwing a few handfuls of Twenty Mule Team Borax around each post would do no harm and might repel insects and fungus.  I've used it  to kill ants where you wouldn't want to use a pesticide because pets or kids might get at it.

I can't see a real benefit to these plastic sleeves other than they look spiffy. I can see a few problems down the road.  Hot tar would be an upgrade.

[Redoverfarm]

Well Don think of your Bog wood. The air is cut off and the timbers remain intact for eons.  If the sleeved were well above grade and in most cases under the house on Peir constuction there would be little moisture allowed into the sleeve or post. If there was any exposed post additional short sleeves could be slid over the post to meet the existing in ground sleeve and sealed. The company even recommends that sealants be used with the product. I could actually see where in some applications they would be beneficial.  The sketch show for a post construction shows the post on the interior of a external wall so in this application I think they would work.  As far as outside exposed application where water could enter the sleeve such as a deck I might be worried.

As far a the chemicals in the wood preserative deterioting the sleeve I wouldn't be concerned as plastics are common in storage application of worst things than that.  In regards to plastic breaking down.  I guess in time everything breaksdown but mostly with plastic it is the suns UV that speed the process.

[glenn kangiser]

I would say there will be problems anywhere the post is exposed to the elements and water can run down it - into a crack -- or any other way into the interior of the tube.

I was thinking that the partial sleeves would be better, but capillary action would pull moisture in and hold it to the sides of the post also.  I think this will cause the same problems I had with the plastic bags.

[Redoverfarm]

I am not in disagreement with you glenn as water is our enemy when it comes to wood.  But unless you were building in an area that had a deep frost line they would work fairly well as the length of the sleeves are in excess of 5' long.  With the standard 2'-3' deep footers there would still be 2 feet above grade which would be well under the decking and structures.  If not like I posted add a 22" open bottom sleeve and seal the joints for what is exposed.