Any Patio/Landscape Gardeners Around - Help Please!

[noTAGlove]

We are having an extension built at the moment, and builder is also constructing a 5m x 5m raised patio. The patio is compacted hardcore at the moment waiting final preparation and laying of the stones

We asked the builder if he could build a 0.5m high raised bed all around the patio. The bed is brick built and will have a couple of coats of flexible render both sides.

The builder laid a 150mm concrete foundation over the hard core and has built the brick beds from this concrete base. I presumed we would polythene line it, and then add the soil and grow some nice plants.

But, just had an oh sh1t moment. We have no drainage for the beds and they will continually waterlog!! So, lining the beds with polythene seems out of the window.

Our best option now seems to be to drill holes through the concrete into the hardcore below, but I’m worried over time that might cause localised settlement of the patio if the beds drain into the hardcore?

Also, if we just add soil directly into the brick beds with no liner, will the brick stay continually wet, transferring this to the outside render and spoiling it?

We’ve asked the builder to stop work on the raised beds while we find the best solution. Any recommendation from those in the know on this forum? I will post pics later.

We’ve probably spent £500 of the £1500 it’ll cost to do the job, as the builder has only built one side of the beds, and the bricks where reclaimed from the extension work. We are wondering whether to cut losses and lose the beds if the challenges are too great, but wife will be gutted.

Any advice most welcome.

Thanks in advance

[Kingstepper]

Will settlement be worse than if area was just lawn etc rather than raised bed?

Edit:- Make it into a pond.

[Mr Pointy]

Usually there would be weep holes in the brick or blockwork to let the water drain but there's a good chance it would eventually mark the rendering & possibly lead to frost damage. I'd look at drilling some large holes down through the base & maybe even improve the drainage down through the hardcore if feasible. If not that then you might need to look at embedding some small 15mm pipes to act as weepholes. Fill the bottom of the beds with rubble & put membrane over this to try & stop soil migration.

Maybe post on here as well as there are a few questions already:

https://forum.gardenersworld.com/
https://forum.gardenersworld.com/dis...elevated-patio

Don't use polythene to line the beds - you'll need something like pond liner which is much more durable.

[hogthrob]

Could you use weep vents through the raised bed walls? https://www.travisperkins.co.uk/Mant...-65mm/p/917287

[Mr Nuttington]

How about planting the raised beds up as a bog garden using marginal water plants that prefer wet feet.

[dulux]

What are the soil conditions in your garden? i.e. is it clay or is it a gravelly material, in other words how quickly does water drain away through your garden. Either way you will need to puncture holes through the concrete base inside the planter walls. The porosity of your soils will give you an idea of number of holes.
As someone above suggests then place a gravel (20mm size) in the base of the planter and cover with a permeable geotextile, then your topsoil infill above that.

[ernestrome]

Maybe containers are a better idea.

[draftsmann]

Do you want the render walls of the raised beds to weather and grow moss and or lichen or would you like them to remain pristine and new. If the former you’ll be in for an easier life. If the latter, good luck.

[stuie-t]

Do you want the render walls of the raised beds to weather and grow moss and or lichen or would you like them to remain pristine and new. If the former you’ll be in for an easier life. If the latter, good luck.

We had some raised bed built recently and was thinking to have them rendered and painted but thought they probably wouldn’t stay looking smart for long. We got them clad in these stone tiles and I think they look quite good:



Sent from my iPhone using TZ-UK mobile app

[noTAGlove]

Thanks all for the comments. We’ve now decided to knock the rendered raised planters on the head.

I’ll be asking the builders to take a sledgehammer to the part built brick walls.