Corrugated metal raised beds

[Mr_Yan]

Someone asked about wooden raised beds. These are raised beds I made out of corrugated galvanized roofing panels. I have 6 total built and placed right now with parts to build two more taller beds.

These are about 95.5" x 32" on the outside of the rims.

The upper rim is made of 2x3 material with a ripped in half 2x3 attached below it. The roofing panels fit inside the L shape that the two pieces make.

The lower edge of the panels is set a few inches into the ground to hold them in place.

And, yes, the OCD is strong here so I placed the beds and leveled them out and squared them so they're in nice neat rows.

 

[Meadowlark]

I don't use raised beds...have no need for them...but if I was in a situation where I needed them, this would be the approach. Excellent!

I had to laugh out loud about the linseed oil painted boards...they wouldn't last more than a year in our climate but your approach is solid and long lasting. Well done.

 

[DirtMechanic]

I need them! Were those utility panels? What gauge?

 

[Mr_Yan]

@DirtMechanic

I used these panels:

https://www.lowes.com/pd/Union-Corrugating-2-16-ft-x-8-ft-Corrugated-Metal-Roof-Panel/3317582

I mostly / nearly followed this vid:

For the tall wall beds I tacked the bottom corners of the panels together with a 3 mm pop rivet and stapled a small firing strip inside at the bottom to hold it nice and straight while placing it. Once in the ground I am sure it will hold just fine.

 

[Mr_Yan]

thanks @Meadowlark

 

[Marck]

Another fun metal for raised beds is cor-ten steel. Enjoy the rust without the rot.

...and yes, corrugated cor-ten is also available.

 

[DirtMechanic]

Another fun metal for raised beds is cor-ten steel. Enjoy the rust without the rot.

...and yes, corrugated cor-ten is also available.

Pretty but that steel price checked me. I would use thin remesh concrete or stone mixes probably at that level.

 

[wkevinc]

Someone asked about wooden raised beds. These are raised beds I made out of corrugated galvanized roofing panels. I have 6 total built and placed right now with parts to build two more taller beds.

These are about 95.5" x 32" on the outside of the rims.

The upper rim is made of 2x3 material with a ripped in half 2x3 attached below it. The roofing panels fit inside the L shape that the two pieces make.

The lower edge of the panels is set a few inches into the ground to hold them in place.

And, yes, the OCD is strong here so I placed the beds and leveled them out and squared them so they're in nice neat rows.

That's excellent craftsmanship. I'm truly jealous of your setup. I wish I had an outdoor space like that.

 

[Mr_Yan]

That Cor-Ten steel above looks like the sea walls around the area. Those are all panels with a ball and socket type coupling between the two panels. Grandpa's sea wall is like that.

Another one that would be cool is take a section of round corrugated galvanized culvert, set it on edge and top it with a lumber rim and use that as a planter. I haven't spent time looking for a section of culvert and I don't like the price Tractor Supply or Farm and Fleet have them listed at.

@DirtMechanic I'd like to learn how to do the concrete style planters but haven't worked too hard at learning it. The problem is I want BIG so if using concrete it would be heavy.

I tried one for the spinning skreet type over a sand mold but failed with my concrete mix. And I think I bit off more than I could chew on a first pass by going too large. And I think I mis calculated and it would have been in the 160 to 200 pounds of concrete range once finished.

 

[DirtMechanic]

@Mr_Yan I have enough interest in those pots to have learned it is not concrete but mortar mix which is used. Portland to start, mortar lime for thickness and portland to finish. I suspect that as the portland does its thing and shrinks a bit the effect must be very much like a tempered glass or metal, where the skin is under tension allowing a thinner but stronger pot. I looked into air entrained concrete, but hypertufa seems lighter. Maybe one day I will get there.

For a decorative effect I believe I would use white portland so the stone or sand or pigment color has a better white balance. Or just add hydrated lime which will make a mortar and not crack. In fact I found out that the longer lime sits the more it literally becomes limestone again. THAT tidbit has made me curious.

Vermiculite and sand and lime, portland and some wire. I think I can, I think I can!

 

[Mr_Yan]

Well this is where making fun of the Civil Engineers at school for years is coming back to bite me. But man, those guys had much easier classes.

I remember one of the vids specifying Type M mortar. He was also signifcantly south of where I live and don't think he had winter to worry about.

Type M​

The last of the four most common mortar types is type M. This type is considered the strongest on its own, with a compressive strength of approximately 2,500 psi for most mixes.

This allows it to be used in a variety of below-grade applications, including driveways, retaining walls, and in-ground foundations. However, type M is also known for its poor adhesion and sealing properties. As such, it should never be used in an application that exposes it to the elements.

Should you need to make your own type M mortar, you can do so with the following mix ratio: 4 parts cement, 1 part lime, and 12 to 15 parts sand.

The last line of the second paragraph - "should never be used in applications exposed to the elements"

I am not worried about bonding ability. The top and bottom will be open so not concerned about sealing in, or out, moisture. But I am worried about freeze thaw cycles breaking it apart.

What about wall thickness. What is a reasonable trade off between strength and weight (I will have to move it in place without using a tractor). I was thinking about 22" OD and a 1" thick side wall.

 

[Marck]

Another one that would be cool is take a section of round corrugated galvanized culvert, set it on edge and top it with a lumber rim and use that as a planter. I haven't spent time looking for a section of culvert and I don't like the price Tractor Supply or Farm and Fleet have them listed at.

Circular slices of the pre-cast concrete culverts used for sewers and storm drains is another material I've always imagined for raised beds, but again the cost of the culvert sections plus the shipping and installation would be prohibitive. It would be less expensive to pour the concrete in place, and then it could also be customized with a variety of artistic shapes and textures.

 

[DirtMechanic]

Well this is where making fun of the Civil Engineers at school for years is coming back to bite me. But man, those guys had much easier classes.

I remember one of the vids specifying Type M mortar. He was also signifcantly south of where I live and don't think he had winter to worry about.



The last line of the second paragraph - "should never be used in applications exposed to the elements"

I am not worried about bonding ability. The top and bottom will be open so not concerned about sealing in, or out, moisture. But I am worried about freeze thaw cycles breaking it apart.

What about wall thickness. What is a reasonable trade off between strength and weight (I will have to move it in place without using a tractor). I was thinking about 22" OD and a 1" thick side wall.

While the lime holds water it also provides flexibility. Becky made some tile-chip landings for the deck. I poured the little pads and she hand glued the broke tiles to a fiberglass mosquito screen which I embedded into thin set mortar and then grouted, which are both a fine sand mortar. I used a latex admix instead of water. Some of the tiles were permeable and lost some glaze due to freeze but the mortars were/are fine. That expansion tensile strength is also what the metal wire and remesh is all about. I do not think compressive strength is an issue, but the more portland the more crystals are locking up interior water and filling voids. Real serious strength could be useful in a thin work. High portland ration will ring like crystal glass when tapped with a hammer.

Just knocking around you see the mortar chart ratios of portland to other materials approaching a 1:4 as they enter concrete strength numbers. Of course the sand improves compression. You could make a mortar easy buying a sand mix and adding some lime to help make it flexible and less prone to cracking in a thicker wall. The real soft mortars are used for soft stone or antique brick. @zigs has a deep understanding of masonry maybe he has a suggestion too.

 

[cntrlwagdnr]

I was an engineer by profession but for our wooden raised beds I finally quit being a perfectionist for the sake of it and got more practical. I used 2x10 regular untreated pine boards with 2x6 tops. That was 8 years ago and they are still going strong. I figure that by the time they need replacing it will still be a lot less expensive than treated wood (and incidentally better for the environment). We don't get much rain here, especially over the summer, but they are irrigated twice daily, so they are constantly damp. Frankly they have even surprised me.

We also have some half wine barrels, but next year we are ditching them and getting some galvanized water troughs from the feed store (Home Depot also sells them). One of our neighbors has a couple and they work great. Drill a few drainage holes and you are ready to go. You can get them in various sizes and heights and they look great.

 

[Mr_Yan]

@DirtMechanic - I need to stop reading your posts as I'm getting too many ideas. I now plan on putting tile mosaics under some gate arbors in the middle of paver brick walkway...

I almost wrote off the concrete planter idea in favor of smaller galvanized feed trough for the area I planned on.