Raised Beds - Which Timber

richbohs · 18-01-2021 9:05pm #1

Hi Folks,

Looking to build some raised beds to plant some veg, can I use pressure treated decking for this, or would there be issues with the chemicals leaching into the soil?

Thanks

Mimon · 18-01-2021 9:07pm

richbohs wrote: »

Hi Folks,

Looking to build some raised beds to plant some veg, can I use pressure treated decking for this, or would there be issues with the chemicals leeching into the soil?

Thanks

Researched this before and no you can't as a lot of nasty chemicals will be leached into the soil. If my back improves over the next month or two will go with just untreated timber.

Apparently will only last a few years but better than ingesting chemicals.

cuculainn · 18-01-2021 9:12pm

Mimon wrote: »

Researched this before and no you can't as a lot of nasty chemicals will be leached into the soil. If my back improves over the next month or two will go with just untreated timber.

Apparently will only last a few years but better than ingesting chemicals.

i have used heat treated timber. beds are down about 3 years now and still fine.

i burned the cut ends with a weed burner where they seemed to be getting some signs of fungal growth and that seems to have stopped that.

Mimon · 18-01-2021 9:17pm

cuculainn wrote: »

i have used heat treated timber. beds are down about 3 years now and still fine.

i burned the cut ends with a weed burner where they seemed to be getting some signs of fungal growth and that seems to have stopped that.

Good call, must try and source some.

cuculainn · 18-01-2021 9:22pm

Mimon wrote: »

Good call, must try and source some.

i am planning on putting down a few more. i was looking into the options again, i think you can get non toxic treated timber too. so it might be worth asking around....

i will probably stick with the heat treated though......always like the look of Monty Dons raised beds that are half collapsed/rotten. so that is the look i am going for!!!!

Reckless Abandonment · 18-01-2021 10:11pm

You could try scaffolding boards (I don't think they are treated) newer ways of treating timber aren't anywhere near as toxic as it was years ago.

elperello · 18-01-2021 10:18pm

Reckless Abandonment wrote: »

You could try scaffolding boards (I don't think they are treated) newer ways of treating timber aren't anywhere near as toxic as it was years ago.

Scaffolding boards are not treated and you can buy second hand ones quite cheaply.

They are no longer safe for use on scaffolding but will last 5-8 years in raised beds.

https://www.donedeal.ie/gardenequipment-for-sale/scaffold-planter-bed-planks/26819411?campaign=14

Frogeye · 19-01-2021 8:58am

Larch is what i used. Have beds in place since 2016 and they look fine so far.

Frogeye

el_gaucho · 19-01-2021 9:04am

I got one of these last year https://www.thegardenshop.ie/timber-raised-bed/

19-01-2021 9:46am

Lining your raised beds with a damp proof course will make them last a lot longer.
It is cheap from the building suppliers .
Just staple it on the inside and over the top lip if possible.

cuculainn · 19-01-2021 11:13am

Frogeye wrote: »

Larch is what i used. Have beds in place since 2016 and they look fine so far.

Frogeye

you will get 20+ years out of larch!!

cuculainn · 19-01-2021 11:14am

BrownFinger wrote: »

Lining your raised beds with a damp proof course will make them last a lot longer.
It is cheap from the building suppliers .
Just staple it on the inside and over the top lip if possible.

any concerns with leaching from the DPC?

magicbastarder · 19-01-2021 11:21am

i have a vague intention of building raised beds using a wattle design; i think i saw monty don do this several years ago on gardener's world.
would just need to source the correct materials for this, i'm not sure who in ireland would supply them.

johnb25 · 19-01-2021 12:13pm

Frogeye wrote: »

Larch is what i used. Have beds in place since 2016 and they look fine so far.

Frogeye

cuculainn wrote: »

you will get 20+ years out of larch!!

Glad to hear it...I have one Larch raised bed in about 4 years. Looks good so far, no lining or treatment on it.

Mimon · 19-01-2021 12:29pm

Reckless Abandonment wrote: »

You could try scaffolding boards (I don't think they are treated) newer ways of treating timber aren't anywhere near as toxic as it was years ago.

I would want to be 100% sure they were untreated before using them.

Have you got a source for your point that treated timber isn't as toxic these days?Any level of toxicity is not good for growing food.

captainshamroc · 19-01-2021 1:14pm

Tough to get Larch at the moment. Have been trying to source some reasonably priced stuff for a while. Last response I got from a local sawmill that used to have a lot of it is 'can't get a stick'

magicbastarder · 19-01-2021 2:02pm

i can't remember the name of the product, but there is a treated wood you can get (treated with acid) which is supposedly environmentally 100% safe, and has an (i think) guaranteed 20 year lifespan submerged and 50 year above ground. it's not cheap, though.

Markcheese · 19-01-2021 2:07pm

If I was putting timber in contact with soil I'd want it to be treated with something , even if it was just fence life or something like that , it's kind of a waste of timber otherwise , pressure treated timber would be preferable as what ever treatment is forced into the wood , in saying that I'd be researching exactly how noxious the treatment would be ...
Charring the wood sounds promising for cut sides but could well take a while ,

eusap · 19-01-2021 3:03pm

I have been looking to build raised beds out of Timber but the price/availability of timber is bad.

I made raised beds from scaffold boards before, 3 x 8ft boards and cost €12, they are not holding up too well after 3 years. Can't find any cheap boards <€10 as they are being used for reclaimed furniture!

I am considering the steel beds from KSB greenhouses, we have them in the polytunnel and they are holding up well after 2 years.

magicbastarder · 19-01-2021 3:37pm

magicbastarder wrote: »

i can't remember the name of the product, but there is a treated wood you can get (treated with acid) which is supposedly environmentally 100% safe, and has an (i think) guaranteed 20 year lifespan submerged and 50 year above ground. it's not cheap, though.

this is the stuff; i suspect simply replacing scaffolding planks every few years would be cheaper:

https://www.accoya.com/uk/

Frogeye · 19-01-2021 5:31pm

captainshamroc wrote: »

Tough to get Larch at the moment. Have been trying to source some reasonably priced stuff for a while. Last response I got from a local sawmill that used to have a lot of it is 'can't get a stick'

interesting....I'm getting a polytunnel shortly and was going to go back to the local saw mill for more larch. I have some left from the outside beds but not enough...

If I'm stuck short term I'll use wooden pallet collars as beds and replace them when the larch comes back. Plenty of them going in the skip at work. I see them for sale in B&Q last year for approx 25 euro a pop 4 foot by 4 foot......

Living Off The Splash · 25-01-2021 11:47am

I purchased my raised beds from Aldi. I have them 6 years now and still doing fine bar a few minor repairs. Cost about €10 for each set. A few are beginning to break in places so I will just top up from Aldi again and reuse the good bits from the older ones as spares.

I try and spend as little as possible on my garden every year as I want to be getting free produce from the garden rather than expensive to produce food.

Reckless Abandonment · 25-01-2021 12:58pm

Mimon wrote: »

I would want to be 100% sure they were untreated before using them.

Have you got a source for your point that treated timber isn't as toxic these days?Any level of toxicity is not good for growing food.

Sorry only see this now.
https://www.finegardening.com/article/does-pressure-treated-wood-belong-in-your-garden

Worth a read.

RainInSummer · 17-04-2022 4:05pm

https://www.boards.ie/discussion/comment/115972314#Comment_115972314

How's the steel beds doing now? Thinking of getting a few in for a polytunnel myself.

I normally make raised beds from 2x9"s but they're after doubling in price in the local suppliers and the steel is working out very close to the price. Plus there's no real cutting or making in them.

21-04-2022 7:18am

Larch is the best by a distance but hard to source.

Raised Beds - Which Timber

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