How to install poly irrigation pipe close to a slab?

Question

Hi,

I have some land abutting my new granny flat bed rooom wall. Can I lay 25mm dia underground poly pipe within that land, close to slab edge beam to water the garden. I was told risk involved being too close to wall slab/edge beam. What are the safe horizontal offset from the slab edge and underground vertical clearnence of the pipe considering all risks. i.e leaking etc. Looking forward to your response.

Thanks

LM

MitchellMc · Answer

Welcome to the Bunnings Workshop community @ak_178. It's amazing to have you join us and many thanks for your question on irrigation.

Please note that plumbing work needs to be completed by a licensed professional for safety and compliance.

It's not unusual to run irrigation poly pipe quite close to a building or concrete slab, and as far as I'm aware, there isn't an official minimum horizontal offset requirement for irrigation pipe.

The main concern would be regularly irrigating right alongside the slab, as introducing excess moisture into the soil adjacent to the footing could potentially cause issues over time, depending on your soil type and foundation design.

The likelihood of the poly pipe itself leaking is quite low, though it's never impossible. Leaks are far more likely to occur at a fitting or if the pipe is accidentally damaged in the future, such as by a garden fork or shovel.

Burying the pipe around 100–150mm below the surface is generally sufficient to protect it from incidental damage while still allowing access if repairs are ever needed.

Here's a helpful guide: How to install irrigation.

Please let me know if you have any questions.

Mitchell