How to landscape a sandy slope with rocks to reduce house moisture readings?

[bob11]

Hi Everyone,

need help with a solution for a steep site down the other side of our house, causing high moisture readings in the walls.

Very sandy and has a layer of limestone rocks that are not cemented in.

I've partly removed the rocks  planning to remove the rest.

Top two level sections - installing drainage solution with existing and new plastic and covering with existing stones. Water will be piped down the slope. (refer images)

But what to do with the slope.

My concern is anything I do will be a temporary fix and then break down, eg plastic liner ripping.

The source of the water is all surface and want to stop it going into the ground and move it all to the front of the property.
Planning to take out all the stones, remove some sand from the left side, to create a slope away from the house.

Relay the stones and cement all the stones to create a seal/hopefully keep the sand dry.

Against the side of the house: I don't want to put stones right up to to the side of the house/damage the wall,  plan to have a gap of a few inch's and fill with cement with water proof additive,  then a bead of sika.

What I've suggested sounds okay or anything else you would consider?

Would you cover the whole site with plastic before laying the rocks?   

What plastic is not going to rip apart and if I did put a plastic down, it would help the rocks slide down in time/crack the cement?

Would be nice to seal the house wall but its too deep, 3 meters or more at the top and at the bottom 1.5m to the pad. ( no existing seal from what I can see - build in 1975 approx)

(The other side of the house is similar - but has already had the rocks cemented, with multiple crack repaired over the years and I will be repairing as recommended in the forum with sika along the edge)

Thankyou for any suggests that can help me fix this challenge.

[bob11]

Thanks Dave, this is a good idea and will consider/see how  the new drainage grill/pipe work to keep  the water on the surface, it could be the second stage of the project.

There was no existing outlet or drain in each wall until the recent work, just a wall with nowhere for the water to go since 1974. Water banked up behind each retainer wall/into the corner near the house wall on the top two levels, with a gap between the retainer wall and house wall for the water to pour down against the house/soil. Plan being that the retainer walls should have little water behind them/ keeping it on the surface with the new easydrain grates. But I need to allow for the agri pipe and I'll use 90m pipe down the bottom slope or two 40mm to allow for any extra work I need to do in the future, cheers.

Bob

[bob11]

Hi Jacob,

sharing my progress where some details have change, can you help with how to make a cement slope where you can see the plastic? 

all the way from top to the brottom, like to avoid cracking etc

like the idea of exposed aggregate/small stones.

The site is now stable and decided to use the rocks for a steps to the top but decided I don’t want these rocks all the way across like the original plan, I agri pipe installed.

Just keen to know what would be ideal to cover the plastic eg am I on the right track like the steps but with smaller rocks? Anything else that anyone has seen as a solution, thanks.

Bob 

[MitchellMc]

Any chance of some images of the area for a bit of context @bob11? You can typically mix up sand and cement into a consistency that will hold position on a reasonable slope. You might need to add some rebar to ensure it doesn't crack. Adding aggregate or small stones before it sets is an option.

Mitchell