Waterlogged raised beds Is it possible?

[Bal]

Hi Guys, we are building raised beds in the back garden on top of concrete the beds will be about 50 cms high with brick walls. OH has just put in the foundations and these are now full of water. Will I have a problem with drainage. Do I need to get him to break up the concrete under the beds. I was just going to lay the cut turfs in the bottom upside down and then fill with top soil
The beds are about 3meters by 4 meters





Are pictures menst to look like this?

[Samurailord]

If you are building beds on concrete with brick walls then you may have problems if you dont leave a gap somewhere to allow surplus water to drain away.

If you don't you will end up with a pond filled with soil

Andy

[WendyC]

Bricks and concrete are impermeable materials. Any water falling on the surface will have no way of getting out. How did you imagine it was going to drain?

[Knight of Albion]

It's not a bad idea in itself, but it will waterlog unless you have a good drainage system to allow excess water to drain off.

As you can see from your own photos, the water has nowhere to go to, so it's building up.

Are those blocks cemented in? Having them sitting on a gravel base would help the water dissipate.

Cutting out a small channel on one side (whichever side slopes the most) of the pit will drain the water away preventing waterlogging as you have at the moment.

[marchogaeth]

So is all that grass growing on concrete (I realise this is what your post implies)? If it's not have you just dug down to a very high water table? What happens now when it rains - where does the water go?

[Potstubsdustbins]

I have two 12 inch deep beds on concrete but they are made of wood and not sealed to the concrete so drainage is not a problem.

If you are going to cement the blocks in place I would get the OH to lay in some 3/4" plastic overflow pipe between the blocks as close to ground level as possible.

[Bal]

Thanks guys. OH is going to put drainage holes in and break up the concrete in places. That should do it I hope.

[Greenleaves]

I would advise insect screens if you end up using side drainage as you dont want to introduce a highway for pests. Just cutup a pair of tights, works wonders

[Ja9]

Think drainage holes a good idea Bal.Bog garden would work well otherwise!