Retaining Garden Wall

[simonturner]

All,

Just after a bit of advice on building a retaining wall in my garden. I back onto a field and have a ditch between my garden and the field. When it rains this ditch fills with water and runs round the back of the estate. Currently we have a concrete pillar and gravel board retaining wall which over the last 5 years has moved backwards and causing the soil to drop.

I have done a little research including getting quotes for someone else to do the work. But £3k is a bit steep for me. I have done brickwork in the past but nothing like this. Mainly filling in gaps and doors and such.

The plan is to remove the old wall and build a new one out of concrete block. The length of this wall is 10 meters and just under 1 meter high. Currently the concrete boards are separated with a gap of about 1/2 inch to allow water to drain. Also at the base of the wall is gravel allowing for drainage. Also at each end of the wall I need to come back about a meter to join the existing wall. I have extended the garden a bit. So a bit like a U shape.

I plan to dig a foundation 30cm below the ditch level and lay a foundation 15cm thick and 40cm wide. With pillars at each end for added strength. I only plan to use 1 row of hollow 9" concrete block and fill in with concrete as well. I will put seep holes in for drainage to allow for the water. Behind the wall I plan to use the gravel for extra draining. Does this seem right? if so how often? Do I need plastic piping for additional drainage? also do I require a membrane between the gravel and soil? ? Will I require additional pillars along the wall?

The top of the wall will just be level off or maybe some very low capping stone's I thought about trying to but my wooden post's for the fence into the concrete hollows. Will just be a simple fence with post's and a few horizontal lengths of wood to stop the kids falling over. Don't want to ruin the view.

Any advice is greatly appreciated. I have also been looking for book's but not seen one yet.
vice on building a retaining wall in my garden.

 

[TicklyT]

Can't help with building a wall, but

Also at each end of the wall I need to come back about a meter to join the existing wall. I have extended the garden a bit.

reminded me of what happened many years ago when some local householders 'extended their gardens a bit' towards a watercourse.

Following some localised flooding, the ditch had to be cleaned. The machine operator asked one householder if they would like to keep the rockery at the end of their garden. When they answered 'yes, please', the Hymac operator dug it out and dumped it in the middle of their lawn.

Their 'extended gardens' encroached on, and seriously reduced the capacity of the drain.

The capacity of the drain was considered to include the complete 'V' shape of the ditch as originally dug, but the homeowners has wrongly assumed the width of the drain only included the narrow section at the bottom of the 'V' cut that was normally waterlogged. Extending their gardens up to that point had effectively halved the capacity of the drain, so the extra bits of garden the homeowners thought they had won had to go.