Do basement french drain systems need any sort of regular maintenance? Such as cleaning them out? If so, how often and what needs to be done? What happens if you don’t do this maintenance?
A properly installed french drain system shouldn’t require any cleaning. The pipes are commonly covered by concrete, making them inaccessible except at the sump pit. The perforated pipe should be laid in a bed of washed gravel (large enough to not fit through the perforations) and covered by several inches (or feet, depending on how deeply the drain is installed) of gravel. Only water should get into the pipes in a properly installed system.
The sump pump should be tested regularly to make sure that it is working but submersible electric pumps require no maintenance.
But over time, the gravel may have sand and silt washed down into it by the rain coming from the ground above, and that can fill in the gaps in the gravel and therefore stop the water flowing out of the perforated pipe.
It all depends on the type of soil above the gravel… if it was sandy loam , used to provide excellent drainage, then the sand can get down into the gravel pit and clog it.
If it takes less than a couple of decades for the system to silt up then it wasn’t installed properly or your house sank into the mud. However, one day the sump pump will break in the middle of the night on a holiday weekend while you are out of town.
I don’t think I’m describing what I have correctly. I was told it was a french drain, but it has about a inch gap between the cement floor and the wall. This gap runs the entire perimeter of the basement. In some areas in this gap, I can see debris in there. I fear that this debris has accumulated over time and is causing some of the water from there to over flow and get on the floor in a specific spot. So as you can see, this isn’t completely covered by the concrete floor, there is a gap.
The basement has two sump pumps and they are working fine discharging the water. The levels in the sump pump pits are kept down at a safe level.
I was thinking of getting a shopvac and vacuuming the gap of the french drains out. I get the impression the previous owner might have swept the floors into this gap. Or maybe over time stuff is just collecting in there.
There should have been grates over that gap, or a physical barrier to keep debris from washing in. Cleaning it with a shop vac is a good idea.
I should mention, some parts of the basement the gap is kinda of protected(?) by a sheet of metal. It looks to be fasten(?) to the floor and behind it I can see the gap. But these metal sheets look worn, so I don’t know how effective they are. But now that I think about it, the problem where water is flowing a little out is where these metal sheets aren’t installed and I can see the gap has debris on it.
Does it make sense that the debris in the gap in there is preventing the water from draining out to the sump pump properly in these specific sections, which is why under a very heavy rain we had recently some water is on the floor?
Not easy to say. The debris could be impeding water flow so that the pump can’t keep up. It may have blocked some section so it doesn’t drain directly and instead the water has to rise above floor level to flow to an unobstructed section. I have the same issue around the sump hole in my basement, I made a dam of dry laid bricks to keep debris from floating in and clogging up the pump. Try a good cleaning and see if things get better. If not you may have to scrape out the channel. Is the channel filled with gravel?
Yes, the bottom of the channel looks like it has gravel in it. At least it does in those sections where it isn’t filled with debris. So I’m assuming after I vacuum out the debris with the shopvac, I will see the gravel underneath it.
I’m concerned that while vacuuming out just the debris it doesn’t include the gravel. But I guess worse case, I could buy more gravel and replace what is there if it doesn’t separate while vacuuming it out.
I guess to determine how much gravel might need to be added back after cleaning, I should examine those areas which have no problem and no debris to see what level of gravel is there to use it as a role model.