Last week we had a reader email us with a patio drain question. Namely, how could he replace the worn plastic channels of his patio drain, which was separating from the concrete floor?
Curiosity about the drain itself aside, I am more concerned with the installation’s integrity. As you see in the photo, he pulled up some of the drain. No trench drain – not even a plastic patio drain – should pull up so easily.
A patio drain installed in concrete should be “gripping” the concrete. As plastic drains age they tend to separate, letting water between the edges. Ultimately, this deteriorates the concrete and creates troublesome moisture within the patio floor. For more information on sealing damp concrete, this helpful article by The Concrete Network has more detail.
This is why most new models of plastic channel drains feature some sort of rib or ledge. Extra surface area gives more “grip” and lends the drain more longevity it wouldn’t otherwise have. The NDS Pro Series channel drain product line prides itself on this feature.
I see two solutions to the underlying problem here:
- Using a concrete saw, cut a minimum 4” on either side of the drain. Remove the old channels and concrete. Pour concrete around a new patio drain of the same size – but one that has more “grip.”
- Without widening the trench, remove the current patio drain. Secure and install a smaller channel drain in concrete. Since the channel is smaller, you may need an outlet adapter to meet the old piping hook-up (e.g., a 2” outlet to 4” pipe adapter).
I hope this gives you a couple ideas about how to fix separating patio drains.