How do I solve backyard drainage problem?

[Benk]

 

 

 

 

[MitchellMc]

Welcome to the Bunnings Workshop community @Benk. It's great to have you join us, and many thanks for your questions about solving drainage issues.

If you were to provide some information about the issue you are trying to solve, our helpful members would have an idea of how to assist. From your images, I can't identify any obvious drainage issues. Do you want to install a drainage line between your house and the concrete slab to prevent water ingress to the foundation?

We are looking forward to some details so we can assist.

Mitchell

[Benk]

@MitchellMc Hi and thanks for your message. I will update with more details. Cheers

[Benk]

Hi All sorry missed dsome crucial information on my post. 

I would like to install a drain betwwen the slab and the house to prevent water ingress under my house. Currently i have some water under the house which is concerning.

My initial thoughts was to cut the concrete so that i have a wider space then install some kind of drain to run the water into the storm drain. Then later put decking and pagola over the slab area to prevent more water getting tonthe slab in the first place. 

Tge question is what kind of syatem would be best to achieve this. Thanks

[MitchellMc · Accepted solution]

Cutting the concrete back and adding a strip drain will certainly help divert any surface water that is running towards the house wall away from it @Benk. Do you have any idea where the water is coming from? If the rain is saturating the soil surrounding the house, hitting a clay layer, and they traversing across it under your house, the strip drains won't solve that. You need to dig a trench that runs parallel to your walls down to the same level as under your house. An agline would then be installed at that depth and the trench backfilled with aggregate. That way, any water traversing under the soil will hit the aggregate and fall into the agline, which will transfer it to the stormwater lines.

Mitchell

[Benk]

Thank you @MitchellMc . The water i reckon is from surface runoff as well as seepage under the footinh. I am to install a retaining wall with an agi pipe trenched near it. As for the surface runoff, just wotking out how to go about it and get the right fall to be effective.

Again i want to thank you foe taking the time toprovide a response. Cheers

[MitchellMc]

Hi @Benk,

I'm not sure whether you'd need to create a retaining wall. Simply digging the trench, laying the agi pipe at the bottom connected to stormwater and backfilling the trench with aggregate would suffice. You'll barely be able to tell it's there.

You'll need to slope the concrete away from the dwelling at a 2% fall. So, 2mm for every meter of width.

Keep us updated, and shout out if you need further assistance.

Mitchell

[Benk]

Thanks @MitchellMc . I am planning on adding a retaining wall to one side of the building where the backyard slopes onto the house and a strip drainage onto the concrete side. in addition erect a patio on the concrete to create an entertaining deck which should limit the amount of water in that area.

I want to thank you for your advise and thoughts and I have more clarity on what i should do to solve the problem. Again thank you so much.

[MitchellMc]

Keep us updated @Benk, and reach out if you need further assistance. We're here to help.

Mitchell

[MaxBan]

@Benk 

Dig your trench using the courses on the brick work of your house which are level, as a guide to the slope of the trench.

 Make a simple water level using your hose and a clear piece of plastic tube.  

 Alternatively use a very tight string line with a bubble level positioned in the middle.