Basment fill and drainage questions

[MikeT]

At the bottom of this email, I have included a picture of my basement pour  for my Victoria's Cottage on the Oregon coast.  Here are my questions:

1.  Looking at the picture you can see a "trench" where we excavated deeper to reach bearing soil.  Now when I fill the trench, should I fill it with whatever fill dirt I can get to or should I use structural fill that will permit water drainage through it?  I should note that at the mid point of that trench is a hole that I dug that goes under the foundation so that water can drain through--I had to do that when the rains here in November and December created a mini-swimming pool.  

2.  Below the slab that I will pour, I was debating the need/value of putting in some perf pipe under the fill rock that leads to the hole I referred to above.  The soil drains pretty well as it is, but.  What do all y'all think?

3. When I pour my slab, should I plan for a slight slope that leads to the same hole/drain area referenced above and then have a drain pipe that leads down to the hole and out to daylight and then down the slope?  I noticed that Glenn referenced planning some slope (1%) in a recent post.

Thanks,
Mike

PS: Yes that is me in lookin not like a real builder, but exactly what I am--a weekend warrior in ski pants  trying to fulfill a dream.

[MikeT]

I should clarify my comment about filling with whatever I have nearby: the excavated material is just out of the picture and is a mix of fractured basalt and deeply dug soil (no organic material).  If I get structural fill, I will get rock (likely 3/4-, road base) from a quarry a few miles up the road.  So the question is, should I go with the stuff that was there or replace with the road base/structural fill?  Note this is for the trench--
I will use the good draining stuff 8" deep all around for the area underneath the slab

mt

[glenn-k]

I would think that if the excavation is done, you have already made it drain and you are going to be using some more drain rock already, it would be good to go ahead and make a functional drain out of it if there is even any possibility that uphill water could somehow find its way there - mole holes etc.- and get trapped on the upper side eventually working its way down to the soil under the floor.

The engineer put a 1% slope -1" per 100" - throughout the basement on the house I'm doing  - adding a drain there would be easy at this point.  You may have no problem as is later, but what if you did and decided it would be good to have one then?  While the engineer in the project I'm doing didn't specify any French drains, we are of the opinion that they are superior to his specified plastic envelope in the rocks and are putting them inside and out of the footings.  We just think it is good insurance at a very low price.