I had a similar problem with the pressure treated posts warping on our pergola. I skinned them with 1X cedar but due to the warpage the corners did not meet nicely. I then used 1x2 cedar along all the corners to hide this defect.

Photos of ours are linked from "My Page". Hopefully you can see sufficient detail to know what had been done.

Good luck.

Thanks Roberts and John, I echo the sentiments on a great project Roberts.

John, you've been an absolute wealth of information for me as I've lurked here over the last several months. Just ordered my TWP116 today, in fact. What would you recommend for the wrap then? I'm going to be painting the posts white, so I had thought using the same stuff that normally trims out house exteriors would be fine.

Hmmm...your 4x4 posts are badly warped, and you want to wrap them. Your choices are bad and badder. More PT=more warped wood. MDF=a total mess, when the soak up moisture and swell...then proceed to mold and fall apart. I like cedar for a wrap, but since you're painting...MDO would be perfect. I make planter boxes out of it, and it's sooo smooth and stable. You may need to put trim on the edges, but maybe sanding will work.

steve

I just dont like mdf or mdo for outside work for a lot of reasons but thats just me after seeing termites get into a couple of projects years ago.I know its normal to use that stuff for outside trim I just disagree.

Wrapping badly warped/twisted posts is a little timei the trick is finding the right size that will work out overall,that is find the worst one and aline the rest with it using a string line. They all will be over size, using the two L shaped pre fab aline the first one with a tack after they are straight intall the second L shaped member to complete the wrap

There is a given with this, it will be a floating attachment that is the two L shaped members can be securly fastened and they can be secure to each other, fasting to the post will be tricky I use a nail gun and a predrill my senco tool is easy to line up with the pre drill, Anyway one guy holds the wrap in place as I nail through the pre drill being very cearfull to mind the string line top and bottom. With this done top and bottom fastening is a snap and really holds the wrap in place.

Material,,,,, all of this can be done with ipe,it can also be done with yellow pine but its the same deal as pt pine speed install, white pine moves a lot less and gives a person more time to work. I vote ipe even though it will take a few more coats of primer before the top coat. J.

I'm with John on this. I won't use MDF or MDO in exposed situations.

Box out the posts with oversized trim. We use redwood or cedar for this. Kiln dried and we pre prime it on all 4 sides before installation.

Mark

John & Mark,

Maybe you aren't familiar with MDO. It's a plywood product, using exterior glue, and the outer sheathing is resin impregnated paper. Waterproof, and paintable. It's used alot in signmaking. I have some pieces out back, buried in soil.

It's not like MDF...not even a distant relative. They just have 2 letters in common.

steve

Paper is the key word Steve thats what the bugs went after on the projects I worked on. They were a good money maker for me we replaced a lot of material completly eat up and of course after they were in the little darlings made a home.
I am as familar with the stuff as I want to be,it probley has its use but it is defently not waterproof or bugproof by any means. J.