Backyard planter and seating

Step 2:

I'll just give generic materials, since my particular measurements aren't necessarily relevant to the reader. The large bench in this case was 12 feet long with an 11 foot seat, and the short bench was 5 feet long with a 4 foot seat. For that, we got:

Materials

• Wooden boards for the outside - cedar, cypress, or black locust are most advised for outdoor use as they are all very rot-resistant. I asked a cabinetmaking friend of mine what he thought of black locust, since it's all the rage in "green" circles, and he said it's good, but very hard to mill. In the end, our local place only had cypress or cedar anyway, and the cypress was very cheap (as it turned out, mainly because they were crappy boards), but seemed like a good bet.
• Plywood for the inside- We went with pressure treated plywood, since it will stand up best to the elements.
• Pressure-treated 2x2 - for the corners
• 1 1/2 inch, 14 gauge steel square tubing- for the structure. Oh by the way, you're going to have to know how to weld...
• Inch by 1/2 in steel channel - For holding up the seat boards.
• Decking screws - specially coated stainless steel screws to hold up to the elements.
• Plastic lining
• Rocks, dirt - to fill. I got my topsoil amended with leaf compost (50/50 mix) in bulk from a local place in Alexandria. $15 for half a cubic yard, which didn't quite fill up the whole planter.

Tools

• 115V flux core wire feed welder
• Abrasive cut off saw
• Chop Saw
• Grinder
• Cordless drill
• Sander
• Vacuum - this wasn't technically used in the creation of the planters, but you're sure going to need it afterwards...

Comments

[chuckyd]

You have pretty much made the plastic useless by punching holes in it. The entire bottom panel will be wet, and will eventually fail. The plastic, itself, will fail if it's biodegradable, or if it's too thin.

There are many alternative solutions for liners, although not as cheap as plastic, unless you can scrounge up used material. Fiberglass and resin is a good alternate, and you can include a pipe at the drain holes to allow the water to drip away from the wood. If you just have the hole there, the water will spread out across the bottom of the plywood.

Other alternatives are metal sheets, such as copper or aluminum flashing. They may not be wide enough for the planter, but you can solder the copper and you can connect the aluminum with foled seams and sealant.

Another altertnate is membrane waterproofing typically used for basement walls.

In all cases the drain holes should have a pipe connected to drain water away from the wood bottom.

[solmstea]

The pressure treated wood should hold up pretty well, even touching soil. The only reason I used the plastic is to keep the soil away from the pressure-treated wood because I'm paranoid about the chemicals leeching into the soil/plants (at the bottom it's less likely to get into the soil), not to make it waterproof.

But if I was trying to make it waterproof, I like the drain pipe idea.