Raised beds from pallets

[JohnathanB]

Hi All,
I hope you are doing well.
The garden is being cleaned and made level but we end up with a lot of top soil and I think rather than dispose of it we could use it for raised beds.
I have some pallets I could join together and made quite tall raise beds 2x1 pallet.
Has anyone done that and could share some tips?

I think this is not something I should just put bare on the ground.
I was thinking to put a thick weed membrane first and perhaps use some old bricks to raise it off the ground then put the pallets on top and fill with soil.
The other thing I think is to put a mesh all around on the inside and attach a membrane so the raised bed is more or less isolated from the sides.
Please advise.

 

[cpp gardener]

Since you don't have to worry about gophers, you can just build it right on the ground using the pallets as walls open on the bottom. How big are the pallets? That will influence how you build the beds.

 

[Tetters]

Jonathan I think that you need to weigh up the pros and cons here. Pallets may not really be the right way to go with raised beds for a couple of reasons i can think of. Firstly, you need to know what contaminants there may be on the wood, and if it's been sprayed by chemicals. Secondly, and more importantly in my opinion, this material will be outside and out in the elements all the time. It will mean that the rot will set in quite quickly in the damp cold weather we are having. The taller you build them, the more prone to collapse then.
I would be all for the weed membrane inside the beds, although I would choose heftier timber or blocks/bricks/ broken paving slabs or similar for the outside construction.
I hope that some of the others will give you more advice, and I do expect that many of them will have better experience and ideas than me. Whatever you decide, I hope it works !!

 

[Mr_Yan]

I'd skip using the pallets. If you want a raised bed either use proper lumber or other wall material. Sure it looks more costly at first but always ends up faster and easier. Even the cheapo tightwad in me has learned my spending 8 hours building a free raised bed isn't worth it vs spending $20 on two 2x8s. Yes, untreated 2x stud lumber rots faster than treated or redwood or cedar but it lasts almost as long and is less than 1/2 the cost.

As to the pallet idea there's several things going on here.

1. Pallets are rather difficult to pull apart as they're usually shot together with a spiral or shanked nail and the nails are generally rusted in.
2. Pallet flat boards are generally pretty thin. Some will be oak but cheaper pallets are often cheap pine.
3. I'm not too worried about contamination anymore than on "normal" lumber. International shipping pallets are kiln heat treated to kill off hitchhikers.
4. Never use "weed block" fabric. It's a disaster and never does well.
5. Why try to build a box full of dirt well above the ground? They may seem like a back saving idea, until you have to fill the box and realize how much dirt it takes and how much that will weigh. Plus they become a daily watering task.

 

[JohnathanB]

Since you don't have to worry about gophers, you can just build it right on the ground using the pallets as walls open on the bottom. How big are the pallets? That will influence how you build the beds.

I think the pallet I have chosen are 80cm x 120cm so 80cm in height.

 

[JohnathanB]

Jonathan I think that you need to weigh up the pros and cons here. Pallets may not really be the right way to go with raised beds for a couple of reasons i can think of. Firstly, you need to know what contaminants there may be on the wood, and if it's been sprayed by chemicals. Secondly, and more importantly in my opinion, this material will be outside and out in the elements all the time. It will mean that the rot will set in quite quickly in the damp cold weather we are having. The taller you build them, the more prone to collapse then.
I would be all for the weed membrane inside the beds, although I would choose heftier timber or blocks/bricks/ broken paving slabs or similar for the outside construction.
I hope that some of the others will give you more advice, and I do expect that many of them will have better experience and ideas than me. Whatever you decide, I hope it works !!

I know what you mean. I have heat treated pallets only.

I'd skip using the pallets. If you want a raised bed either use proper lumber or other wall material. Sure it looks more costly at first but always ends up faster and easier. Even the cheapo tightwad in me has learned my spending 8 hours building a free raised bed isn't worth it vs spending $20 on two 2x8s. Yes, untreated 2x stud lumber rots faster than treated or redwood or cedar but it lasts almost as long and is less than 1/2 the cost.

As to the pallet idea there's several things going on here.

1. Pallets are rather difficult to pull apart as they're usually shot together with a spiral or shanked nail and the nails are generally rusted in.
2. Pallet flat boards are generally pretty thin. Some will be oak but cheaper pallets are often cheap pine.
3. I'm not too worried about contamination anymore than on "normal" lumber. International shipping pallets are kiln heat treated to kill off hitchhikers.
4. Never use "weed block" fabric. It's a disaster and never does well.
5. Why try to build a box full of dirt well above the ground? They may seem like a back saving idea, until you have to fill the box and realize how much dirt it takes and how much that will weigh. Plus they become a daily watering task.

Right. I have a heavy duty membrane not the cheap, crap fabric that disintegrates mid season.
I agree with your point that the structure is weak. I was thinking about connecting it together with steel rods and brace it together half way. I was thinking about creating a "foundation" made of loose bricks so the pallets are not sitting on wet ground.
I have these heavy duty EUR pallets as well but I want to use them for something else.

I have excess of soil and I think I would easily fill 3x these 120cm x 240cm raised beds.
You're saying that raised beds save the back but they lose moisture faster than the ground level soil.
You lobby for:
1. a thicker but untreated timber
2. brick or concrete block walls
3. dispose of the dirt/soil

 

[Oliver Buckle]

Rather than a membrane how about cardboard ? Some has plastic in it, but if you are a bit selective it will stop weeds, and when it disintegrates you should be past the problem stage. The top soil you want to use may well have weed seeds in it though. Personally I would keep it low so you can use long handled tools easily if you want to, but still don't break your back bending. My experience is creating a wooden wall loses a lot of moisture, I used the split trunks from an overgrown leylandii, so about 4" thick, but they still dried out quickly, I guess if they were square it might be less so, mine were a bit long and narrow.

 

[JohnathanB]

ok, in that case it makes more sense to use bricks or concrete blocks to build the raised beds or don't bother and just dispose of the material.

 

[Tetters]

Hey Jonathan, it seems like you really wish you hadn't asked ! The thing is, as so often in MY case, if it is a project started that goes miserably wrong - as again in MY case, it would be a pity.
It would be a shame to dispose of good material, so maybe a re-purposed plan would work.
If you carry on with your original plans, which you clearly gave a lot of thought to, I think you should end up with a very usable space to grow stuff in comfortably for at least three years, and maybe more. Whatever you decide, I for one wish you good luck and every success. Nothing ventured, nothing gained aye... I would love to see the finished results- go for it.

As a PS...I have been reading about the Japanese method of charring wood by torching the outer surface. I believe this makes it deter mould and decay as well as boring insects. Maybe you could look it up online to find out more, unless you already know about it?

 

[Mr_Yan]

Part of my answer is I have no clue what your plans are for how to build a raised bed out of pallets. There's as many ways to build it as times ones have been built. But deconstructing pallets for lumber is usually harder than it is worth.

I would NOT dispose of any soil you have removed and have as "extra". Soil is very valuable. Life on this planet is only possible because of a few inches of top soil and the fact that it rains.

I have heard of charring fence posts as a method of preventing rotting out.

I built a few raised beds with untreated lumber that I then oiled and it lasted several years.

I agree cardboard is great but weed block is not. I've used a bunch of cardboard in my gardens. I've even built compost bins out of wire mesh and cardboard.

There is no RIGHT or WRONG way of building it and what may be right for me could be totally wrong for you or Tetters. It is all based on what you have, where it is going, what it will be doing, and how you want it to look (or how your wife doesn't want it to look). There are things I have done one year only to yell "what was I thinking" a few years later when tearing it apart. (e.g. styrofoam packing peanuts are bad for bulk fill, don't use glass for the bottom of a container, plastics usually fall apart in the sun and make a brittle mess). If you want I have some pics of my raised beds in [url = https://www.gardening-forums.com/threads/sheet-metal-raised-beds.25031/post-241998] this thread[/url].

Heck I've had a small garden where I covered the ends of a pallet (where the fort truck tines would go in to lift it), put the pallet on the ground, filled it with dirt, and called it a garden. It worked OK but I won't do it again.

 

[JohnathanB]

what if I use a damp proof membrane (DPM) instead? I would cover all the walls including the floor so the moisture does not escape to the ground? This would be a deep raised bed, I reckon about 70cm of soil.

 

[Oliver Buckle]

In my experience DPMs disintegrate over time into lots of fine pieces of plastic, I would stick to using it round the walls where you can remove and replace easily as soon as it shows signs of going. There is nothing wrong with water coming up from the ground when it's dry, and you don't want a muddy pond if it's wet.

 

[JohnathanB]

In my experience DPMs disintegrate over time into lots of fine pieces of plastic, I would stick to using it round the walls where you can remove and replace easily as soon as it shows signs of going. There is nothing wrong with water coming up from the ground when it's dry, and you don't want a muddy pond if it's wet.

I have thick DPM that normally goes under the concrete.

 

[Mr_Yan]

My opinion. Build the raised bed. Use the wood. Skip any plastics, membranes, or landscape cloth. If you're really worried about things growing up form below smother it with a few layers of cardboard.

700 mm tall will use a lot of volume. You must have a lot of extra soil.

 

[JohnathanB]

My opinion. Build the raised bed. Use the wood. Skip any plastics, membranes, or landscape cloth. If you're really worried about things growing up form below smother it with a few layers of cardboard.

700 mm tall will use a lot of volume. You must have a lot of extra soil.

I mean I don't mind the weeds because I know the soil is free of their seeds but the thing is the moisture. Considering tall raised beds without a proper barrier will dry out very quickly.