Building a raised bed

sancho

Am planning to build a raised bed at the weekend, over the site of an old pond. The pond has been drained and pretty much filled with rubble, hardcore, stones etc.

My plan is to cement 4 posts in the corners, then nail/screw/coach bolt some planks of wood into the posts, building them up a layer at a time. It's about 6ft x 4ft. Not really sure of what sizes post/planks to go for. Obviously it will be filled with soil so there will be plenty of weight in there, am planning on going up to about 60/70cm high and don't want the wood coming apart/breaking under the weight.

Any tips?

ormus

standard size fence post will be ok. 3x3 or 4x4 even better.

Wookey

If you can source some scaffolding planks then there should be no trouble with them taking the weight, if your side timbers are going to be a bit thinner then perhaps along the two longer sides you can add a couple of posts in the middle to take the weight.

sancho

ormus wrote: »

standard size fence post will be ok. 3x3 or 4x4 even better.

Thanks, how far underground would be best to cement them?

Wookey wrote: »

If you can source some scaffolding planks then there should be no trouble with them taking the weight, if your side timbers are going to be a bit thinner then perhaps along the two longer sides you can add a couple of posts in the middle to take the weight.

Am leaning towards scaffold boards, sleepers are nice but a bit pricey, scaffold boards seem a happy medium, where do you buy them though?

PeteW

sancho wrote: »

Am leaning towards scaffold boards, sleepers are nice but a bit pricey, scaffold boards seem a happy medium, where do you buy them though?

Phone your local scaffolders and ask if they want to get rid of their more knackered ones. I got a dozen 13ft boards for a quid each.

Wookey

PeteW wrote: »

Phone your local scaffolders and ask if they want to get rid of their more knackered ones. I got a dozen 13ft boards for a quid each.

Wot he said ^
One other option though usually more expensive is reclamation yards.

ormus

i wouldnt even bother cementing them in. that sort of weight aint going anywhere soon.
just cut the post ends to a point and drive them in to the ground.

treat the ends first with some creosote type product.

sancho

PeteW wrote: »

Phone your local scaffolders and ask if they want to get rid of their more knackered ones. I got a dozen 13ft boards for a quid each.

Cheers, rang a few yesterday and the only one who answered was selling them for £4.50 each, thought it was a deal but perhaps not!! I might ring some others tomorrow.

What did you do to them? I have a daughter who will be running around soon so don't want to creosote them i presume, will any old coating be ok? obviously they will be used to grow things so don't want to affect that

ormus

there are more modern preservatives now. water based and non toxic. ie colored fence paint.
thatll be ok for the structure generally. although you may have to redo it every few yrs.

for the leg ends in the ground, id use a more stronger product.

sancho

ormus wrote: »

there are more modern preservatives now. water based and non toxic. ie colored fence paint.
thatll be ok for the structure generally. although you may have to redo it every few yrs.

for the leg ends in the ground, id use a more stronger product.

What would you do if you'd, hypothetically, already cemented them in...........

ormus

nothing.
id just hope to to get 5/10 yrs out of em before replacing them.