Need advice on raised bed construction

[charlz]

As soon as it rains, the treatment chemicals in the wood can leach out and easily come into contact with the soil. What posts are you talking about? You would drive posts into the ground to support a raised bed? Sheesh. Just toss some untreated lumber onto the ground, screw the corners together, fill with dirt, and you're done.

Since the wood is on the outside of the roofing I see little potential for it to get past the roofing and into the bed soil. Water tends to run straight down. Yes, if it leaches it will get in the soil below the bed but with a 24" high bed that is not much of a concern.

Use of posts depends on how long of a bed you are making. Long beds will bow if you do not put something in to support them. The taller the bed the more likely it is to bow out and eventually lead to collapse. I like to do things right the first time so I don't have to do them over.

I was referring specifically to the corrugated galvanized roofing (as was suggested). Does that look like simple, unpainted galvanized metal to you? No, it's covered in layers of paint and other unspecified coatings. Go to a roofing manufacturers website and check it out. Are those chemicals you want in your food? Who knows, but not worth the gamble (IMO). Galvanized pipe, on the other hand, is plain metal and uncoated.

Uhhh, maybe you need to do a bit of reading. Galvanized pipe is plain metal COATED with zinc, same as hot-dipped galvanized steel roofing which is what I took Jinman's recommendation of "corrugated galvanized 26 ga sheetmetal" to be. He never said anything about painted metal roofing.

 

[charlz]

I've had back surgery and still have herniated discs so height is an issue for me. I'm also a cancer survivor who eats organic so chemicals leaching out of treated lumber is also a concern. I like the idea of corrugated, galvanized metal raised beds. I ran across a couple of designs and wondered what you guys thought of them.

Raised beds | Garden Gidget's Blog

Easy, Affordable Raised Bed - Southern Living

This design is more what I was thinking.

How-to instructions for constructing galvanized metal raised garden beds

Posts and PT wood on the outside versus the inside keeps it out of soil contact and addresses that concern. In my beds the posts are on the inside and now that my beds are mounded and the post tops covered I forget they are there and hang up on them with rakes, digging fork, hoes etc.

 

[Larry Caldwell]

I built mine out of rock built up as high as two feet laid as dry wall. Lasts forever, reasonably cheap. Even if you don't live in a rocky area, you could use landscape blocks from Lowe's instead. Easily removed (I used "1/2 man" rock). Looks nice forever (with the occasional rock adjustment). Holds heat during the night to keep those spring seedlings warm.
Mf

Bingo. I am getting ready to build raised beds, and will use landscape blocks, from the block company, not Lowes. I can buy them the same place Lowes does and miss their markup. They will be attractive and permanent. Thanks for the tip.

 

[kubota4me]

This design is more what I was thinking.

How-to instructions for constructing galvanized metal raised garden beds

Posts and PT wood on the outside versus the inside keeps it out of soil contact and addresses that concern. In my beds the posts are on the inside and now that my beds are mounded and the post tops covered I forget they are there and hang up on them with rakes, digging fork, hoes etc.

Great example!

 

[jeff9366]

I made my raised beds out of 1" thick concrete plank, often called Hardeeboard, although mine was a different brand. Corners secured with Simpson Strong-Ties. They bowed out a bit when I filled them so I have a reinforcing stake at 6' on the long sides.

My beds are 6' X 12' X 12".

Concrete plank has worked well for three years. You have to moderately careful not to put a lot of weight/force on the exposed top edge.

 

[ustmd]

I built ours--4 x 8 and 3 x 5 out of 2x cedar. Has worked great.

 

[RalphVa]

I put in 6 raised beds that are 2 2x4s high and 4x8 for $300 worth of treated lumber. The new treated lumber doesn't leach dangerous compounds like the old stuff did. I put a short 2x4 in each corner and cut the bottom at an angle to make a point. I then just drove these stakes into the ground to anchor the bed with my bucket loader.

 

[Finnster]

This design is more what I was thinking.

How-to instructions for constructing galvanized metal raised garden beds

Posts and PT wood on the outside versus the inside keeps it out of soil contact and addresses that concern. In my beds the posts are on the inside and now that my beds are mounded and the post tops covered I forget they are there and hang up on them with rakes, digging fork, hoes etc.

Wow, nice looking beds.

Is this a certain type of PT lumber? Stained? All I see around here is Yellawood which is always the green PT color.

I was thinking of doing the 24" high beds to avoid so much bending over too. I'm not doing a massive garden, so the cost is ok.

 

[charlz]

Is this a certain type of PT lumber? Stained? All I see around here is Yellawood which is always the green PT color.

What they show on that webpage is the same PT lumber you generally find at Lowes, Home Depot etc around here. Sometimes you see the green colored stuff but the reddish/brown is more common.