We have just finishing building a new house, and we need to look at retaining walls and drainage.
For the retaining wall, the plan is to use concrete sleepers with ag pipe behind it for drainage. However not sure where to start with the drainage that would be required to move the surface water away from the side of the house (currently it just pools there and stays for weeks as it has no where to go). I would appreciate any recommendations?
Digging down may be difficult, as we have a lot of rock underneath, soil is also clay based.
Welcome to the Bunnings Workshop community @Jess5. It's wonderful to have you join us, and many thanks for your question about removing surface water.
You'll need to install drains that capture the surface water, similar to Everhard EasyDrain. You might like to run them for the full length down the side of the house, around 40cm out from your wall. The clay could be graded to channel the water into the grates. Topsoil or pebbles can then be added over your clay. If the soil is difficult to dig into, I'd advise going with the Everhard 1m EasyDRAIN Compact Polymer Grate And Channel, as it's only 80mm high.
Another option instead of drainage channels would be installing drainage pits at regular intervals down the side area. The Everhard EasyDRAIN Polymer Grate And Floway Pit is the most slimline of these, but once you get the pipe connected underneath, it's likely going to require more digging than the channels. You could install a drainage pipe under the surface, but once again, by the time you add gravel over the top, you need to dig a decent trench to fit the pipe and gravel topping.
Have you considered concreting the side area? That would be an added expense, but it allows you to grade the area away from the house, have the rain hit the concrete, and run into any of these drainage options.