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raised beds
November Member
Posts: 139
in Talkback
Have just had some boards delivered today to replace existing worn out ones.
The original beds are very high , and to replicate will mean boards will have to be two high instead of normal single height.(need height because of disability problems ).
Being so high weight of soil has caused bowing of boards etc. The original beds made of wood but not scaffolding boards.
Has anyone gone this high with boards?
If so how to fix one on top without complications ?
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I've used very stout railway sleepers which, whilst lower than scaffolding boards, enables me to build higher levels on top if I want to.
I think your best bet is to dig soil away from the bowing sides (heap it in the middle or away from the bed) and then drive a number of very strong stakes deep in around the outer edges to buttress the sides to restore their alignment and prevent future bowing, before returning the soil to the beds.
Unfortunately, you can't beat the physics of the situation: earth is heavy stuff and I would have thought even scaffold boards are not really up to the job once you start increasing the weight behind them like that, not unless supported from the other side.
I hope you can resolve the problem - I'm sure a lot of us know how difficult it is to bend over a bed that is just too low for comfort.
An important factor is the compaction of the soil. If your soil is loose and crumbly, then no amount of posts driven into the ground is going to support the required depth of soil.
I built some raised beds a few years ago. Our soil is light and sandy (no good for gripping posts) and full of stones that constantly send the posts out of true. So I concreted them in place (1 in each corner and 1 in the centre of each of the long sides for the largest beds).
Because it's a sloping site facing north, I wanted to bring the north-facing side of each bed up to the horizontal to get more sun. As a result, the north-facing sides are between 350mm and 400mm high, while the south-facing sides are 200mm
For 2 smaller beds (1.8m x 1.2m), I used 4 posts, 1 in each corner, while 2 larger beds (3.6m x 1.2m) have 1 in each corner, plus 1 in the centre of each of the long sides.
The timber I used was all 50mm thick, width either 150mm or 200mm. Screws were Timber-Tite, size 6.5 x 80mm and 6.5 x 145mm. Like most timber, some of the boards have 'dished' across their width, but the screws have held everything together very securely. Scaffolding boards are thinner (usually 38mm), so would need more supports to prevent bowing.
Thanks for the sensible an helpful comments.
Will try to achieve my aims somehow , good old trial and error , hopefully with the least error possible !!!