creative end cut on 2x4 for lap joint

[david babcock]

Would you make a salad bowl out of pressure treated lumber?

On my raised beds I've always gone about 3 courses high with 4x4s. I use regular cedar 4x4s from the Borg. It's all about drainage, I think, as far as rot goes. It's like fence posts. The secret to long lasting fenceposts is not pressure treated wood. It's handling drainage properly by putting a good bit of gravel under the post so you don't make a "concrete cup" that holds the fencepost and the water.

Think the same way with the garden. You should dig down INSIDE the garden once it's built. Dig down about 12", and mix that in with lots of peat moss and lots of quality compost to fill the raised bed. Since you never walk IN the raised bed, it will have great drainage to 12" underground. As a result, right around the garden (under the frame), water will run off to the easy route inside the raised bed.

I'd suggest laying out the garden pathways with about 2" of pea gravel before you start building. Build the raised beds with 4x4s sitting on gravel. When it is all done and solid, dig down 12" inside. You'll lose a little pea gravel, but for the most part you'll be left with a layer under the 4x4s. Then line the inside walls of the raised bed with heavy plastic that goes from the bottom of the hole and comes up to 1" from the top.

I had 15 year old raised beds built this way at my old house. I made the first one without the plastic, and the ants consumed it in 4 years (and gardening was no joy for the two years before that when THEY were there in great numbers). The plastic ended the ant problem, saved water, and it doesn't rot because it's buried and hiding from Sol's UV rays.

good stuff joe! youre way ahead of me. I hadnt gotten that far yet, so I appreciate the good advice on the prep and layout. what is it about the plastic that stops the ants? seems like they would just go around.
David,
Ive always wanted one of those ryobas. before i decide to go out and buy one, is this going to be a real task to cut 50 2x4s with a hand saw?

Prashun, I was thinking qty 3 of 2x4 stacked vertically. I think with 4x4 posts in the corners this should be plenty tall and sturdy?

[Joe Angrisani]

Joe, if i line them all up and run a carriage bolt or dowell through them, can i avoid glue? I think it would be advantageous to allow the wood to creep and move over time a little with changes of temperature and such.

I would think an unglued dowel in a snug hole will work just fine. There's really no seasonal movement to speak of along the lengths. All you want to do is keep the sides from bowing out unevenly.

what is it about the plastic that stops the ants? seems like they would just go around.

The plastic keeps the interior of the wood frame from being constantly wet. Moisture plus wood equals ants in my experience. Take the moisture out of the equation and the ants move to your neighbor's garden.

[Prashun Patel]

David-
Personally, I've done my raised beds with 4x4's. I have no posts in the corners. I stagger the ends like I indicated below (not for looks; for stability) My courses are 3x high.

To fasten them together, I drilled vertical 3/4" holes thru the courses along the lengths and then hammered rebar stakes flush to the top into the ground. It stays together and stable fine. I don't line the inside with anything.

[Mike Schuch]

how to cut this corner lap joint on 2x4s ?
Its embarrassing to even ask this to a group that probably think this is Lincoln log childs play.

I guess the "proper" thing to do is get a nice Dado blade set- but lets say that I want to get a little more creative. How does one make this top cut without standing an 8ft pressure treated 2x4 on its end?

Im trying to think outside the box- is there some jig or adjustment this rookie can make to keep from having the blade cuts run/extend/drag past the cut out area on the 2x4 ?

The wife wants some raised bed box gardens. But Im trying to think of a creative joint that would be simple, strong and easy to replicate on a hundred boards.

LIke this:Attachment 187873
Attachment 187874

Don't forget to put some expanded steel sheets under the beds to keep the moles and gophers out.


Check Craigslist for some used Trex... or post a wanted... no rot... no chemicals.