In article ,
said...
A member of my family is having a new home built. The basement has been
poured (it has poured walls) and they are waiting for the walls to fully
"set." Well, yesterday it rained, and what we observed was that the entire
basement floor appeared to be covered with a significant amount of water (a
piece of electric wire laying on the floor was completely submerged),
EXCEPT for the corner where the sump hole is. I then recalled that the
side of the basement where the sump is was the part that the concrete
finisher did last (it is the side by the egress window) and therefore, if
there was a small bit of extra concrete, that was likely where it wound up.

In any case, it appears we have a situation where as much as an inch of
water at the far end (give or take a little) would have to run UPHILL to
reach the sump. Now I should also mention that this basement is built on
pure sand (literally - there is a sand mine just a mile or so down the
road) and drainage is very good, so I don't really expect that there would
be too many situations where the basement might flood - but on the other
hand, if the unforeseen ever did happen, it would be much easier to deal
with the problem if the water naturally ran toward the sump. I should
probably also mention that this basement was constructed with extra
headroom, so pouring more concrete over the existing floor would be doable
(in terms of not losing space). And, the general contractor seems like an
honest person, but I'm not sure that he's aware of this problem yet.

If the floor got wet because you have no basement windows and the rain
came in that way I would not worry. If there are perforated pipes
correctly installed under the floor and/or a perimeter drain leading to
the pit then the pit will work (once you put a pump in it).

I used to always assume that they pitch the basement floor to the pit for
drainage, but I see them poured flat most of the time now.