Interesting idea.... I use regular pine boards for my raised beds and do not have any floor at all. But when it is time to take them out it is always just half of a board is rotten from inside, but screws already do not hold well. If it would be double, I could just change inner layer. What I don't know if double will bend more then single. You may need to screw them in multiple places as they can wobble different directions. That may increase the cost a lot - metal is always more expensive.

Floors/bottoms in raised beds is seldom advised as it always creates drainage problems. The exception is using hardware cloth if one has a bad vole or gopher problem. But in this case what you are really building is a container rather than the typical raised bed that sits on the ground. Very different situation and you will have to use something. I'd suggest that you look at plans for what are called garden trugs - waist high wood containers that use V shaped bottoms (open at the point of the V to insure drainage)..

EX: Garden Trug

How to build a veg-trug

They - any bed - also need to be more than 6" deep. 10-12" deep minimum. Can you edge stack 1x6 boards to make the 12" deep? Sure. Will they bow? That all depends on the length you use. 4' lengths don't bow, longer will over time. So with 6' or 8' length the solution is to edge stack 2 boards and then overlay 1 additional board over the joint on the outside to reinforce and attach to the base 2 using galvanized wood screws. Follow me? The reinforcing board also gives it a decorative look.

Hope this helps.

Dave

I use 5/4 deckboards for my on ground raised beds. with 2 x4 s on the corners. yes they are treated and no I am not overly concerned about it. they are cost effective and last. the OP is looking for something different than the title indicates. I have seen plans on net for handicap type raised beds could Google that.

Here a link for raised beds built atop milk crates. Might work for you.

I used galvanized corrugated metal sheets as the sides with pressure-treated 4x4 corner posts and 2x4 frame across the top and bottom. You're looking at about $25/sheet (3 needed) and then the cost of the the lumber and hardware. Assuming you don't cut the sheets (other than the end pieces) you get a 2.5' deep, 12' long (instead of 8') by whatever width you want bed for around $100, and it should last a lot longer than a wood bed.

Mine don't have bottoms, but I did attach hardware cloth to the bottom as we have severe gopher issues. I wouldn't have bothered had we lived somewhere it wasn't a problem.

Agree the title is a bit mis-leading (unintentional I'm sure) as what
is described in the post isn't a raised bed in the usual sense
(framework that sits on the ground) we talk about. He describes a big
container on legs. So different construction will be required. There
are more discussions about this type of waist-high container over on the
Container Gardening forum here.
Dave

Ah, yes, misread it, was thinking 36" HIGH not 36" off the ground. Nevermind, scratch that, mine would be entirely too big for that.

Hi all and thanks for the feedback. Sorry if the title was misleading- I ran out of room to put what I want.

So yes, this is a "raised" garden planter on legs. I found this and I think Im going to do a very similar design: http://www.instructables.com/id/DIY-Raised-Bed-Planter/ and use the hardware cloth or slats along the bottom. I will use two boards on top of each other to give a depth of 12".

I really like the idea of using the "overlay" method mentioned by Dave to basically band them together in the middle. With this method, I think I am going to do a single layer then band the middle on the outside.

The raised-bed-planter image looks very much like the planters I had for blueberry propagation. I used all oak boards wit treated 2x4" legs and screws to assemble. For a first few years I could lift them and move around with a forked loader but lately the boards rotted enough at the ends and the screws started deteriorating as well. But i "slapped" these together with scrap materials which I had available and didn't expect a long life.

My suggestion for you is to use stainless steel bolts through the corners if the 4x4" legs are treated. It would not be a bad idea to have galvanized angle iron under floor boards on each end floor added floor support. You could cut through the angle to allow the outer 3" of angle iron to be bent, drilled and bolted to your legs. That would give added support to the weakest part of the setup.

I found a lumber yard that is about half the cost of big box stores in the area. I can build a 2" thick 8'x4' raised box for under $100. Im going to go that route and just get the 2" thick. Im going to use just a few floorboards spaced about 5" apart and use hardware cloth over top of it.

I think you'll want heavy duty landscape fabric on top of the hardware cloth too Jason. Too much soil will fall through hardware cloth alone.

Dave

I was thinking about that. Okay I will get some of that too.

Vinyl window screen can also be used to keep the soil in the bed but it needs to be stapled on between the wood and the hardware cloth. I used this method for a salad table I built a few years ago.

This weekend I bought all the lumber and hardware needed to make the beds. This project is starting to add up! Hah. I have one bed halfway done. This is a 12" deep bed. I will be starting on the 20" deep one soon.

Just a quick follow up to show the finished product for those who might be interested. Finished these up yesterday and will planet today as long as the rain holds out. One of them ix 8'4'x20" and the other is 8'x4'x12". Im pretty darn happy with how they turned out. Attached is a picture before the wheel and landscape cloth went in and 2 finished shots.

Those look great! I'd love to see pictures later of how your garden progresses in them.

We have very similar ones that we bought from a neighbor who moved to Maui. Ours have the bottom slats very close together (maybe 1/4" between planks.

The main problem we have had was that the neighbors put in too rich of a mix and the soil was too hot for a container. Now, a couple of years later things are growing fine.

You might want to head over to the container gardening forum to get some hints! Nancy

Well we started to fill the smaller 12" deep one first and with it less than half full, the middle started sagging. So I had to do a quick modification to add support in the middle. Added 3 legs with 3 wheels in the middle with a 2x6 cross member. This is much more solid! I really really hope to get planted this weekend.

Last weekend after working my butt off all day finishing the second vegetable bed, buying a bunch of cement blocks for the back third planter and transporting them down the hill to the back yard, and hauling 15 loads of dirt down to the backyard. I tried to move the large bed and one leg slipped onto the grass. As I pushed, all the weight tore the wheels and recently added middle legs off. To say I was devastated was an understatement. I had spent a lot of money and the past 3 weekends trying to build something that would last a long time. Today I stopped pouting and fixed it using a car jack and car wheel dollies to push it off the grass to its final place. It no longer has wheels but now it is in the correct position and has plants in it.

Thank you! Im glad it is over and I wont need to build anymore for a lloonnggg time!

They are not raised beds. They are elevated beds. After placing earth and after watering they will be quite heavy. That is quite an investment. That expense would most certainly make me have second thought.

Len

True, but its done, done well, and I wont have to do anything for awhile.