Treated landscape timbers: how to drill for the rebar spikes?

I’ve used landscape brick to border flowerbeds in the past. This time I want to use treated landscape timbers.

My local hardware store has precut rebar spikes to pin it into the ground.

Should I drill a hole just a little smaller and drive the spike in like a nail?

Or drill for a snug fit and tap it through the wood?

I wasn’t sure if the landscape timber would split if I *drove *rebar through it.

I’ve seen it drilled. I doubt driving it in would be an easy task even if doesn’t split the wood right away. On top of the that the wood may shrink over time and will certainly change dimensions with the weather and the wood may split later without a hole slightly larger than the spike. You might look into the very long screws used to construct log cabins among other purposes. That might reduce your labor. Even if you have to drill with those it’s a smaller hole and the work will go faster.

I drilled a very close fit so the rebar was snug but no real resistance to driving it through.

If I’m remembering correctly, a 1/2" rebar will provide a little resistance going in to a 1/2" hole. I can’t imagine what advantage would be had drilling a smaller hole and having to whack it through.

Attaching timbers on top of those, I’d use spikes and pre-drill them.

I was debating between using a 1/2 spade bit or a 7/16.

If the 1/2 rebar is snug in a 1/2 hole then thats all I need. I didn’t want the timber raising up when bumped with a lawn mower.

At least get yourself an auger bit.

Are you using the little timbers with the rounded edges, or 6x6?

Concur.

These from home depot.

:confused: you don’t like spade/paddle bits in wood?

Are you talking about a twist bit? those will over heat very easily. I’ll have to drill very slowly.

No, not a twist bit. An auger bit.

Like this

ETA: or like the examples KneadToKnow provided before me.

ok. I’d forgotten all about that style. I see Lowes has one.

I see what you mean. A big spade bit sometimes wallows out a bigger hole if you don’t keep the drill rock study. They also have a nasty habit of binding and the drill will twist in your hands.

I will never see your project, so it shouldn’t matter a whit to you, but I’ve never seen anything made out of those that looked good after a couple years. That may have something to do with DIY under-engineering, though. Hard to pass up at the price.

I would insist on an auger bit for a big treated 6x6, but surely a decent spade bit would do the trick for this application.

Of course, it’s a great excuse to buy a new bit, sooooooo…

Unrelated anecdote…I needed to get a new 1 1/2" spade bit to make a hole through a 4x4, and got one with a screw tip. I was almost scared how it chewed a hole right through, drawing itself the whole time. Awesome.

FYI, if you’re planning on growing edibles you may want to be careful with treated timbers.

if you use a spade bit then you likely might need to remove the shavings as you drill by removing the bit and inverting the wood or vac them.

an auger bit periodically raised will throw the shavings out as you drill.

a spade bit is good when you need nice holes and have the time.

an auger bit is when you need a hole and want to get it quickly.

Thats why my other flowerbeds are edged with brick. That is some hard, hard work. Done that too many times.

HD does have 7 in. x 9 in. x 8 ft. Used Creosote-Treated Railroad Tie

I shudder to think how much they weigh.

Would the standard 6x6 pressure treated last longer than the landscape timbers? Deck posts are tighter grained. Might resist rotting a lot better.

Thats an option worth considering. Glad I started this thread. I got some very good suggestions on drill bits and material.

I used a 6x6 PT 12’ long as a replacement corner post on a second-story deck 6 years ago. It looks pretty much like new now, no splitting, etc. Of course, it’s not lying flat on the ground.

A friend who works for the railroad offered to get me railroad ties many years ago for a home project. They weighed a ton, and were a bitch to work with. But I drove by that house recently, and they look like they did when I put them in twenty something years ago!