Garden retaining wall

[Adamc]

Hi I'm wondering if someone can give me a bit of advice, I have recently started a project to build a 1.1metre high retaining wall at the top of my garden, the ground is chalk, the footing was 45-50cm wide, 35cm deep, this was filled with 25cm of concrete. The wall, having not built one before I'm fairly chuffed with. I plan to put weep holes in at intervals and also a drainage pipe at the back with the shingle etc , 1st question is how far from the base of the wall does this need to be placed to work as it should? The ground level on the front side is higher by 30cm at a finished level so i planned to have two outlets either end of the wall about 10cm above this level, this would mean the drainage pipe behind the wall would be around 45cm above the base footing taking into account the drop off needed for drainage. Would this be too high for the drainage to work as intended.
2nd question there is a lot of water currently sitting infront of the wall and behind on the footing, will this be an issue once I've done the above? Should I be directing the water away from the front of the wall also?
 

Thanks 

 

Adam the DIY(er)

[Mr Punter]

If it is perforated pipe you can lay it in flat.  Put the weepholes about 50mm above the paving level every 2 or 3 blocks.  You could core drill and waste pipe instead of weeps.

[cwr]

I'd guess that water sitting behind the wall is not great.

 

Some info on this page may be useful if you've not already seen it. Scroll down a good bit to get to retaining walls. 

 

https://www.pavingexpert.com/featur03

[Tosh]

A drain at that height behind the wall sat on pea gravel will do next to nothing. The water would have to be 450mm deep before it can make use of the land drain, you might catch a bit of surface water draining from the top but water will always take the esiest route which will be past your drain, through the gravel and continue sitting on your foundation. What about lifting the level up with concrete, then allow for pea gravel to bed your pipe on then membrane to stop all the mud blocking it up, reinstate gravel, wrap with membrance and fill with soil - plenty of pics on tinternet. Your puddle in front of the wall - is that just where you dig out for foundation? would not reinstating with concrete sort that out?

[Adamc]

@Tosh funnily enough the water was there after a night of rain but drained away during the day, in answer to your question re the front of the wall that is just where the ground slopes down to the footing that I dug for the wall, I intend to fill and level to around 2 bricks up from the base, with natural soil and free draining gravel. I did think the land drain would need to be on the as close to the bottom as I could get it, then again we have a very free draining soil around these parts so maybe weep holes in the wall would suffice. 

[Adamc]

This is the right side of the wall it's finishes going into the neighbours wall. As I'm taking the ground level up 2 blocks at the front  I could essentially get a diamond cutter, taking the drainage pipe exit  as close to the bottom of the wall as possible dig a trench directing pipe away into the garden, as it's chalk it should easily drain away, and you won't see the pipe as it'll be under the ground. Thoughts? And thanks for all your replies, really appreciate it. Sorry about the bad drawing 😅