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dwt
Dec 7, 2004, 04:54 AM
I have two drainage systems in the basement. The first set of drain tile was inatalled around the inside of the footings and leads to a sump pump. The second is around the outside perimeter of the footings and leads to a "french drain." The problem is after several days of soaking rains, the french drain evidently fills up and water backs up at the bottom of the basement stairwell and then seeps in the door! What options do I have?? Thanks in advance!

labman
Dec 7, 2004, 05:54 AM
You may have to replace the French drain with a sump pump. You might look at your overall lot and do some regrading to eliminate anywhere water stands on the surface. Also make sure the sump pump dumps the water where it can't flow back or to the French drain area. This could lead to less pressure on the French drain.

One quick fix might be to rent a heavy hammer drill and drill maybe a couple of slanting 3/4'' holes from the stair well floor through the foundation to allow local relief to protect the door. The water that now comes through the door, would have a shorter route to the sump pump. If it makes things worse, you could cement them back up.

speedball1
Dec 7, 2004, 06:09 AM
Have you considered digging down to the french drain near the basement stairwell and tieing it into the drain tile that picks up the sump pump?
That way when the french drain loads up the over flow that would normally flood into your basement would be picked up by the sump pump and carried away. In the meantime, under normal conditions the french drain could leach water back into the soil and the pump would just be a backup. Sound like a plan?

dwt
Dec 7, 2004, 07:33 AM
The French drain is approx. 25 yards from the house and is deep enough that water flows "downhill" to it... so I'm thinking the top of it would be about 10- 12 feet under some very heavy clay! Was hoping to avoid any heavy rental equipment, but... Had considered the check valve type of device that fits into the drain itself. Any experience w/ these? Thought one of these might stop the backflow and allow the water to seep into the sump pump drain? Had considered drilling holes as suggested but think that if the french drain is full, the gravel under the poured floor would be also as they are at the same depth. I have (temporarily) placed a portable sump pump at the bottom of stairwell but have needed to play w/ the float in order to have it cut on before the water reaches the door sill and off before it is running without prime. Appreciate the assists and speedy replies!

speedball1
Dec 7, 2004, 03:29 PM
Has this been a ongoing problem over the years or something that just started up? What drain are you referring to when you mention "checkvalve"? Is your french drain drain a bed of gravel or a PVC pipe with drainage holes? Where woulld you place this check valve? Is the french drain already tied into the house sump or does the water back up for 75 feet to get in your house?
I'm missing something here. What is it? Regards, Tom

dwt
Dec 7, 2004, 03:57 PM
It has happened about 5 times in the 4 years we have been here. Had assumed at 1st that it was due to having no cover over a 6 foot wide stairway into basement. We never had significant amounts of water- never more than a puddle at the threshold, but then again- we caught it quickly. It wasn't until I covered this area this spring and a month back found the stairwell filling up with water did I realize that the water was actually backing up the drain in the bottom of the staiwell. I have "fixed" it w/ the additional sump sitting in the stairwell but do not see this as a permanent fix and we are starting to finish the basement. The french drain is a deep pit of gravel that the drain tile (perfoprated pipe)feeds into. When building 4 years ago, I intalled drain tile around the inside of the footings and lead them into a sump pump pit. Due to the heaviness of the soil and amount of rain we get and fear of frequent rural power outages, I had an afterthought before foundation was backfilled, and installed drain tile around the outside of the foundation and ran it (including drain at bottom of stairs) into the french drain. The french drain pit is lower than the footings so water would flow there. Evidently when this is full, it is pretty much a straight shot back into the stair drain. The top of this drain is where I was considering putting a check valve with a floating seal that works opposite a toilet flapper. Hope this fills in the blanks. Thanks and sorry for the aggravation. DWT

speedball1
Dec 8, 2004, 07:48 AM
The problem I see with a check valve is where would it be installed and what type would you use? If the check valve looks up then a "swing check's",(and that's what you're going to need,) is out of the question. If you install a "spring check" then you would have to calculate the weight of the water before it floods through your door sill and locate a spring check valve that has the tension setting that you need. The only way a swing check works is in a horizontal position. To install a working swing check you would have to remove the drain and build a grated sump down to where the drain pipe's horzontal and install a swing check on the open end. Great solution but it's going to take some effort on your part. Keep me in the loop and let me know how you make out, Regards, Tom

labman
Dec 8, 2004, 08:10 AM
I am still mulling this over. A float type check valve like in a wet/dry shop vac might work. Of course once you stop up the drain, the water may find another path.

I still like the idea of tying the inside and outside drains together. That way the sump pump clears all the water out when it is wet like now. In the summer, the water from a hard storm can flow to the french drain even when the power is off. You could rent a core drill and punch a 3-4'' hole through the poured foundation. It is easy to drill horizontal holes if you anchor bolt the base to a vertical wall. Trouble is, you need about 4' for the drill.

If you have a good down hill lie, give up on the French drain and let the water run out on the ground.