Question about PT landscaping timbers and re-bar

[wood_newbie]

I'm going to be building a raised garden bed out of pressure-treated landscaping timbers, and I wanted to know how long re-bar would last in this material.

First off, this is for a flower garden only, not a veggie garden, so anything leaching from the PT lumber will be of no health consequences.

Secondly, this will be in a relatively hidden part of the yard, so it don't need to look incredibly purdy. For this reason, staining from the metal vs. wood is also of no consequence.

I'm planning on predrilling holes through the timbers, then pounding re-bar through and into the ground about two additional feet. So my question is two-fold:

1. How long would this re-bar last before it rusted so badly from the PT chemicals that it lost it's holding abilities?
2. Is there a better material I could use similar (and as cheaply) to re-bar that wouldn't rust so badly?

The bed will be three timbers high, so roughly 6 - 9 inches in total height.

TIA.

[nailshooter41]

Not much will be cheaper than rebar. If you have a chance, make sure you interlock your corners. I have found this to be the best way to prevent movement.

If I build one of these, I put the frame or design (if it is just a wall) and tack it together with some small galvanized nails on the edges. Once assembled, I take my drill with a spade bit and a 12" extension (HD or Lowe's, $6) and chuck up the 5/8" bit. Drill every

16 inches if it is on unlevel ground, and only go about 16" into undisturbed soil.

If the ground is pretty level, then the stakes are only about 24" apart. In all cases though, you need to make sure your timbers have some 40d galvanized at the joints if you have them in the field. Also, no matter what the length, drill though your corner or turn joints and stake those. I never go more than 16" into the undisturbed soil, and never use less than a 1/2" bar.

If I were afraid of rust, I would simply spray the bars with car undercoating before installing. At any rate, I still see one that I put in many years ago (7-8?), and nothing has failed anywhere on it. It looks like it has a few years left, and nothing was done to prevent rust. I don't think rust will be a problem for you, regardless of the PT you are using. And if it is just plain old landscaping timbers which are mostly dipped/soaked, not PRESSURE treated, you won't have problems. When you cut one, you will see what I mean. I don't think I have ever seen one of those things that the treatment material went more than 3/4" to 1" into the wood.

I line mine completely with plastic like visqueen, rolling the plastic all the way up to the edge to be but off later for appearance sake. This will help keep unwanted plants from sneaking in as a root or runner.

Robert

[cdo]

I have about ten years in now on mine done the same way here in Houston. I used half-lap joints at the ends. 24 inches down was way overkill - both from the standpoint of pounding them in, and later getting them out if necessary. I recently had to pull a couple out, and gave up and pounded them all the way in (gumbo grips!) - too much work.

There was no significant rusting of the rebar, and minimal staining of the wood.

Cliff

[robo hippy]

The rebar will outlast the wood by years. You may be able to pick some up from a construction site scrap pile. robo hippy

[jd]

I've done this is in the past, and agree with the other posters. However, I recently had a job doing a large retaining wall with railroad ties. The owner didn't want rebar, so I broke down and tried Timberlock screws. They're great. You'll need a 1/2" drill to drive them in, but they're quick, easy, and solid as rock..... They are a bit pricey, but then it only takes about 15 seconds to drive one, aas oppoased to drilling, then driving in rebar....

YMMV

--JD

[TRS80]

[Pat Barber]

Rebar is overkill for a three level flower bed.

This is an excellent reason to go buy a new tool !!!

PALM NAILER

Go get a palm nailer and some 5" ring shanked spikes designed for this purpose. I can assure you that once these spikes are driven in pt, they will NEVER, EVER come out for any reason.

The flower bed will never move and in the event you outlive the PT wood, who will care.

If you can find the wider landscaping timbers, they can be mitered at the ends for a very nice look.

Most folks just half lap or just stack them up.

[e-mail] wrote:

[wood_newbie]

Thanks for all the useful suggestions guys...I thank you, and my hydrangeas thank you.