Composite deck material

[Jim Dunn]

I'm planning on building a couple of window boxes and thought about using this type of material. Does anyone know, for sure, if it can take constant contact with dirt and moisture?

Secondly has anyone PVC glued this material. I think I need to use screws even if it can be glued but it would be nice to not to clamp it for screwing.

I started this project and then got to thinking about the above questions. The one thing I noticed is when planing, it filled up my separator almost immediately. Apparently the fluffyness of the plastic material prevents it from compacting:eek:

[Paul Ryan]

Jim,

I have one deck made out of the composite material and one out of cedar. There are a couple of things I don't like about the composite material for deck but neither have anything to do with your question. My composite deck is actually a covered porch. In the winter it has snow on it, and in the summer the water hangs around a little longer. None of this has caused any problems. I would not expect this material to be any problem with how you plan on using it. It does seem to expand and contract a little more than wood does so that it another thing to think about. I have never glued it though so I have no idea how that would work. All I know is that PVC glue can glue just about anything. Lot of folks don't like gorrila glue, but I have had good experiences with it. As long as you understand what it is. I glued an aluminum strip that guides a screen door for a sliding deck door down to the wooded bottom of the door frame 7 years ago and it is still there. It has not broken free, and had to be glued, and that door gets used alot. So if it can glue aluminum to wood, I think is could glue plastic to plastic.

[Ed Labadie]

I've used Gorrilla glue on Trex before, it's what the mfg recommends.

Ed

[Dan Bowman]

From what I've ready, bonding the composites is difficult. Some suggest epoxy can work if the board surfaces are prepped first: http://www.westsystem.com/ss/gluing-plastic-dimensional-lumber/
Good luck, and let us know how it turns out

[Jim Dunn]

Thank you gents. I appreciate the reply.

[Rich Enders]

Exposure of composite decking to dirt and water is no problem. Just think underground piping.

The currently available composite decking comes in a number of species. Primarily these are PVC, and Polyolefins such as Polyethylene, and Polypropylene. This information will be given with the technical data on the decking, or can be obtained off the MSDS which will be available on line.

The PVC is bondable with standard pipe adhesive, and a number of other adhesives. The Polyolefins are very difficult to bond, and most bonds will come apart in a season.

The movement of plastics is primarily from the ambient air temperature, and not from moisture. You need to plan on about 4 inches of growth per 100 feet in going from the cold of winter, to the heat of summer.

[Don Morris]

I'm not so sure about exposing the composite to dirt. My composite deck doesnt' touch the dirt. It comes down to the ground but stops there. That's where the PTP starts. And it's suported by PTP which goes into the ground: that's designed to handle that type of use. I was going to store some left over pieces under the deck for "just in case", and the top (older) construction hand who put the deck up said it wasn't a good idea to leave the composite material sit in the dirt. Dirt/constant moisture has a definite effect on wood (composite has plenty of wood in it) that's why we treat it for that application > PTP. I suspect that's what the construction hand was getting at.