Raised bed

[RickH]

There are 2 sections of the garden that are bounded by round-top concrete edging - these items:

grass lawn on one side and flower bed on the other. aprox 50mm sticks up above ground.
SWMBO now wants me to convert the flower beds to a 'raised bed'
So be nice to find a way to increase height of these by around 200mm

Don't want to put anything too thick .. as it then loses garden space.
I also don't really want to dig them out of the concreate they are set in.

Be nice to have something that would sit on these downward loading is fine .... but sideways loading is issue ... if garden side is filled with soil ... need a way to prevent then pushing over.

I assume 200x 50 decorative sleepers could be used ... but to avoid losing 'height, would have to look at adding a piece to it to create the rebate, not sure how well that would work ... and then fixing to concrete ....
Don't want to 'overlap into lawn area.

Welcome suggestions / ideas

 

[Why Not Indeed]

Your picture looks OK, actually, but like you say, how to rebate the sleepers. Could probably do it with a circular saw and a guide fence [it's easier to rebate a larger piece of timber this way than smaller]. You would want to make sure you can firmly fix the sleepers together at the corners to resist lateral loading. And do whatever you can to stop the sleepers coming in to contact with soil.

I would suggest gravel boards, but you don't want to dig out the existing edging. I can't think of a way of attaching gravel boards on top of the edging that wouldn't look fugly or be weak.

 

[jj4091]

I would suggest gravel boards, but you don't want to dig out the existing edging. I can't think of a way of attaching gravel boards on top of the edging that wouldn't look fugly or be weak.

Couldn't he just put them behind the edgings. Seems like the easiest and best solution to me.

 

[RickH]

Doing the rebate would be OK, I could use a saw table ... it's just that assuming I did a 75mm rebate .. that is wasting a lot of wood.
Alternate would be to 'affix' a 50 x 75 or similar piece to bottom of sleeper to maintain full sleeper depth on top of edgings - not sure how effective I could 'join them' using a good glue and pins may work.
The 'garden area is effectively an E shape so I could fix sleeper to each other at the 90 degree corners.
As the intent is to increase soil depth I could add some galvanised angle iron stakes pushing garden edge of timbers against the concrete edging, as these stakes wouldn't be seen

 

[RickH]

Couldn't he just put them behind the edgings. Seems like the easiest and best solution to me.

At 4" thick (typically) ... so both sides would reduce width of garden bed by 8" .... too much garden would be lost. Unless someone has a suggestion of some edging which is less than 4" thick, which can still hold soil in place.

 

[Why Not Indeed]

I think jj4091 is referring to gravel boards when he says "them" - definitely not 4" thick.

If you're open to using angle iron to support the sleepers then have them flush with the inside of bed, no need to faff about rebating or affixing strips of timber on to them. They would then appear to be levitating from the outside, that may or may not be the effect you're after!