On May 25, 5:51 pm, Geo wrote:
As those of you who read my initial post know, I'm in the process of
digging out a hole for a paver patio that is outside the walkout
basement - which happens to be the low spot of the property. To
recap, I just removed an old
slab of cement outside the walkout door and as I was digging about 10"
down a water puddle formed along the foundation and I ran in to (what
I thought was) a drainage pipe. This pipe runs parallel to the
foundation about 10" below the level of the basement floor. I
presumed the water drained from this pipe to the sump.

As it turns out the previously mentioned pipe turns out to be an old 5
foot piece of 2.5" pvc that was half under the old concrete slab at
the doorway with the other half just covered by dirt and gravel. The
pipe was sitting on gravel and was atop plastic and parallel to the
house against the foundation. It looks like it was intentionally laid
this way. The thing is the pipe does not connect to anything. It's
just 5 feet of pipe lating there. I can remove it.

Which brings me to the next problem. Why is there water pooling
against the foundation. Granted, it's below the level of the basement
floor, but I'm not sure that I can lay a patio atop it. Does this
water pooling suggest that the drain tile is not working correctly or
is this a natural type of occurence? next, can I safely put a paver
on top of it? The water doesn't seem to get any higher than a certain
level. Even if I try to fill the hole it seems to seep in the
ground. It doesn't rise. For patio purposes I suppose I could back
fill the hole with gravel, pack it - that would get me about 10", then
the subbase of the patio wouldbe another 5" with a 1" sand base and
2.5" paver stone.

I'm at a loss here.

If you have that much cover, and you use graded, compacted, fill,
there's no problem with the patio pavers. That's the least of your
worries.

The pipe makes no sense, I could come up with theories, but who
knows? The water level is an issue. I'd imagine you've been looking
at this for a relatively short time and haven't experienced heavy
flooding, torrential rains, snow melt - whatever is the worst case
scenario is in your area - so I wouldn't be in a hurry to lay those
pavers until you're very confident you understand the water/drainage
situation.

I'd definitely want to have some drainage in front of that door,
either running to daylight or to a drywell. Concrete slabs will wick
up water, so even if there isn't standing water in the basement, the
high water table could wet the slab, damage stored items and promote
mold growth.

R