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:
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?
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.