Composite boards - Garden boxes

[andrew whicker]

Hi,

Every once in a while I get a job to build some ADA garden boxes for a local company. It's a fun way to make some money on the side for me and a relatively simple project.

I've used cedar the past two times. This time they are asking me to consider composite boards (like Trex). I don't know anything about composite boards, but I'm thought they expand with temp way more than cedar? True? The majority of these garden boxes are walls that hold the dirt in. I'm not sure if composite is strong enough.

Anyway, I'll do some looking on my own. I'm assuming composite companies are constantly innovating and there is probably a composite solution that is lower maintenance and lasts longer than cedar. I'm open minded.

cheers,

[Bill Dufour]

Hardie planks do not survive flat on the ground. they get too wet and turn to mush. I used some as grass boards on a fence and they have done well over 5 years or so.
I bought a rubbermaid 100 gallon ABS? stock trough yesterday at tractor supply for a raised garden bed. It was about $90.00. I use the big 350 gallon one as a fish pond. Half buried in the ground with cast concrete retaining wall blocks all around it.
Bill D.

[Mel Fulks]

They used to make plastic or metal liners for flower boxes. But I haven't seen any for a long time.

[marlin adams]

Composites has come along way in a few years but the good products cost. Here is a link to a couple and maybe do a little homework and talk to the company and maybe ask what their expectations in going composite. These 2 links I find are the leaders in composite but both Home Depot and Lowes carries and maybe your local lumber yard does to. Now be careful like mention before some composites are not worth the fiber they are made of, so do a little research.

https://www.trex.com/products/deckin...xoCLMMQAvD_BwE

https://www.timbertech.com/?gclid=Cj...xoCBuEQAvD_BwE

[andrew whicker]

Thanks for the responses. All I'm really seeing so far is 1" x's which don't give me a lot of confidence. Here's a photo of the style we build for them:

IMG_20180306_101247_086.jpg

[Bill Dufour]

At Tractor supply they had welded pipe frames with a plastic feed or water trough at the top. In my climate the plants would die in the sun in thoe planters since the roots would reach outdoor temperature and more. plants do not like it when it is over 100 degrees or so.
Bill D
They call it a "bunk feeder"
https://www.tractorsupply.com/tsc/pr...l?cm_vc=-10005

[Bill Dufour]

https://www.google.com/search?biw=12...0e8ff-vi1XGwM:

[Alex Zeller]

I made the wife a box 42"x12"x8" out of PVC boards for a couple tomato plants. She had been using sheet rock buckets. Home Depot sells them in 3/4" 4x8 sheets. I don't have any pictures on my computer but I should have one on my phone if your interested. I used PVC because I could glue the boards together with PVC glue and I made them to match part of the house. They are 1x6 boards with a raised panel like a cabinet door. They might be a little small for what you are looking to do but it looks like you have a steel frame inside. If so I think with a little planning it should work just fine. Since the glue makes them water tight I had to put some weep holes so they can't fill up. What I can't answer is how they will handle dirt freezing/ expanding in winter as I don't plan on leaving it out.

[Lisa Starr]

Cellular PVC is non-structural. If a frame of steel or wood can be used then the PVC may work. Cellular PVC is very flexible so I would be concerned about them bowing outwards from the pressure of the dirt. Both Azak and Certainteed have fairly complete "instructions" available if you do some digging online. I've had quality issues with Royal in the past.

[andrew whicker]

Cellular PVC is non-structural. If a frame of steel or wood can be used then the PVC may work. Cellular PVC is very flexible so I would be concerned about them bowing outwards from the pressure of the dirt. Both Azak and Certainteed have fairly complete "instructions" available if you do some digging online. I've had quality issues with Royal in the past.

Are all plastic boards PVC based then?

Thanks for your response!

[Steve Rozmiarek]

You'll find that the manufactured products (Trex or Azek) will be a lot more floppy than a real board and heavier. They also don't do as well as you'd think in ground contact. You'll want to change the design a bit to account for that. I've never tried it, but wonder if cement board, like 1/2" hardibacker would hold up, maybe as a liner? It works will enough on exterior masonry, it might. Personally I'm thinking the cedar you use already would be a better product though, and I can't imagine that anything is going to last forever doing that.

[Erik Loza]

Are all plastic boards PVC based then?

Most of the "decking-type" boards out there use a plastic called HDPE as their base (I was in the plastics industry for a while). Solid sheet PVC is available from specialty plastic distributors and is strong but expensive and only really used for chemical handling tanks. HDPE is inexpensive but soft and expands and contracts a lot with temperature, etc. I suppose if someone was building planter beds that were no more than maybe 6" or 8" high, then HDPE would be OK but no way I can see it being used for framing or vertical walls needing to hold several hundred lbs. of soil. Just my experience and good luck with your search.

Erik

[andrew whicker]

Thanks to everyone that responded.

I'll no quote the plastic board idea. I'll stick to the tried and true.

Thanks again.

[Jon Endres]

Possible to find a lumber supplier in your area that sells black locust? It will last for decades in that application.

[Frank Pratt]

Ipe will last just about forever for this & is cheaper than most quality composite decking.