Is it OK to concrete over agi pipe?

[harrygeria73]

In May 2023, I had a qualified plumber install agi pipe at almost foundation level against one wall of my house to stop storm water getting under my house. The agi pipe was covered with blue metal, but it was left uncovered.

The concrete surface adjacent to the wall slopes TOWARDS, the wall where a lot of

 

 

water drains into the blue metal. That concrete surface should ideally slope AWAY from the wall into a drainage Chanel I had installed previously for that purpose.

My question is: Is it safe to have have the blue metal covering the agi pipe covered over with concrete? What is the process of doing this?

Thank you.

[MitchellMc]

Welcome to the Bunnings Workshop community @harrygeria73. It's wonderful to have you join us, and many thanks for your question about concreting.

You can’t concrete over the blue metal, as it serves as a filter that allows water to drop down through to the agi pipe. Covering it would block this drainage function and could lead to further issues. One solution could be to add a raised edging along that side of the concrete slab to prevent water from running toward the wall. However, the most effective fix would be to re-grade the slab to slope away from the wall.

Since the agi pipe was installed and should be collecting the water running off that side of the house, I’m curious—are you still experiencing water getting under the house? If so, it would be helpful to know a bit more about the situation, so we can provide further guidance.

Please let me know if you have any questions.

Mitchell
 

[harrygeria73]

Thank you Mitchell for your comments. To answer your question whether I'm still getting water under the house. I did an inspection under the house yesterday and I did not see water there. But the areas where water previously collected or drained 

are damp to varying degrees, suggesting to me some amount of water may still be getting in somehow, especially during periods of heavy rain. Elsewhere under the house looks dry.

(I  have taken note of possible solutions you have suggested so far in your reply above).

I look forward to your response.

[JacobZ]

Hi @harrygeria73,

It sounds like the drain you installed is working as it should on this side of your property, but water can track along brick lines and find gaps that are not immediately obvious to appear from places you do not expect.

Is there any kind of waterproofing on the wall and foundation on this side of the house?

Are there any other areas that you think could be contributing to the water getting under the house?

It seems like you are well on the way to a solution, but there may be more you can do.

Let me know what you think.

Jacob