Crawlspace Drainage ??'s

DUSE

I dident no where to post this ,,, so here it is.
I have a 6' crawl space (my house) with a slab floor
That always has a couple inches of water in it.
It comes up from the ground (not gutters or bad grading)
It has a pump in the corner but the slab is not pitched so the water stays.
I'm going to cut out the perimeter and put in the perforated pipe to the pump.
My question is ...I think I know the answer, I just want to make sure.

The slab butts up to the footing, then there's 6-8" of footing before the block wall.
I DON'T cut into the footing, Right?

My plan is(tell me if it's wrong),cut out 6-8" along walls,
Remove concreat and dirt.
Put in the rock,Put in the filter,put in the perforated pipe(pitched of course) cover the top of pipe with the filter more rock ,then finish with concreat
Is that right?

concretemasonry

Standing water in a crawl space is definitely a problem.

Your idea of getting rid of the water instead of trying to fight the sealing problem is good. You will also remove a lot of moisture from under the slab.

1. Definitely do not cut the footing.

2. You will probably have to cut out more than a 6-8" strip because it will be easier if it is wider and just as much cutting (more contrete though).

3. The cut does not have to be right at the wall. Make it about 6" from the wall so you can go deeper with the pipe if you want - the footing will not be in the way.

4. Use a filter cloth and the rock should not be too coarse (3/8" is better than 1").

5. The pipe does not have to slope since it is open and perforated.-Holes on the bottom half. Even if it flat it will work kust as well since thrench is just the collecter.

This is just a general description and your situation may pose some minor differences, but water does not run uphill.

__________________
Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

woodmagman

If you are just trying to remove the water from on the slab, another solution that is going to require less digging is find the area on the slab where the water pools first and dig a new sump pit there. With only one row of drain down the center could be hit and miss...water takes the path of least resistance. The center of the house may not be the path it wants to take.

denick

Duse,

From what I read the top of your slab is even with or lower than the top of the footing?

If this is true you only need to add 2" of stone ( bring the top of the stone 2" higher than the top of the footing) cover the stone with a vapor barrier ( We use one of the coated kraft paper materials and have had great success) and pour your slab. This will address water coming up under the existing slab and any water that might be coming out of the bottom of your cement block wall.

__________________
Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

DUSE

Thanks guy's.
I'm gonna go with cutting out along the walls and maybe a length down the middle.
If I go with your suggestion, denick ,I'll lose 4-5" (if I'm understanding you correctly?) and I dont want to lose that.
My only other thing I'm not sure on is ...
How much rock(3/8) do I put around the pipe(it does go all the way around ,right?)?

Michaeljp86

woodmagamn is right a simple sump pump pit will work fine. If under the floor in pea gravle it will work great. I would suck all the water out and watch where it comes in at and put the pit there.