Three companies have proposed the same solution, more or less, to address pretty bad flooding in our crawlspace: Dig a trench around the interior perimeter and install a perforated pipe that leads to a sump pump. All good, I'm convinced. But the more information I get from the various vendors, the less certain I am of which one to pick. A few questions:

  1. One company told me that with the “old” method of using a round perforated plastic pipe surrounded by a bed of gravel, the pipe will silt up and eventually either get blocked or jam up the sump pump, even with the filtering action of the gravel layer. Their solution is to use the Waterguard system that sits closer to the wall and is wrapped with a sock or sleeve, as is the stone bed. Is he right about the silting problem?

  2. How important is it to install more than one sump pump? One vendor says one (with a battery backup that operates the same pump) is enough because they're very reliable. Another says I should have at least two.

If anyone can share some of their knowledge on this topic, I’d be grateful.




1 Answer 1


In my area conventional drain tile loops are used extensively. They often use "sleeved" pipe, which has the silt sock you mentioned. They generally work well, assuming that they're not crushed by concrete work or careless backfilling.

If you have extremely smooth clay-like soil, silt may be a concern. The microscopic grains in clay can make their way through the sock over time. Otherwise, you won't see much silt at all after the first season or two. My sump water runs completely clear after heavy rains, as do most others I've witnessed. This is anecdotal information, of course, and your results may vary.

In short, I wouldn't be concerned about using a sleeved "conventional" drain tile loop, assuming that you haven't heard horror stories from a bunch of folks in your immediate area.

I don't know of anyone who has needed more than one sump pump. If you find that yours is running more than say 10% of the time, it might be wise, but that's something you can evaluate later. It's really a matter of risk tolerance.

  • I agree that a sock may not be needed unless a very sandy loam soil (and then you wouldn't need the drain in most cases). depending on the drain design I have found very few homes that needed more than 1 pump. some homes had enough drainage with the new drain installed the pump only runs with the hardest rains.
    – Ed Beal
    Commented Mar 23, 2017 at 19:01
  • Oh, I'd use the sock in any new install. Cheap insurance.
    – isherwood
    Commented Mar 23, 2017 at 19:06

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