What are the advantages/disadvantages of placing drain tile on top of
the footer vs. next to the footing?

I ask as I am getting a lot of water under my basement the past couple
of years and my sump pump runs much more frequently than it used to.
Water is seeping into my sump pit via a rift which has been created
just below point where the interior drain (from under my basement) is
located. The point where the water is entering my sump pit is 8"
below the floor of my basement. My perimeter drain is not connected
to the sump pit, but rather to a drain pipe which daylights down a
hill behind my house.

Of interest is the fact my perimeter drain does not appear to be
capturing any appreciable water as there is not any flow out the end
of the connected drain pipe. This drain pipe has adequate slope from
the point it ties into the perimeter drain and I recently dug down to
ensure the "tee" (perimeter drain to drain pipe) had not been
compromised. It was in working order and when I ran a hose onto the
exposed drain tile, the water did flow nicely out the drain pipe.

Is it possible that surface water is working its way under my footers
and bypassing the drain tile (perhaps due to its location on top of
the footers and not next to them)?

As noted earlier, the point where water is entering my sump pit is 8"
below the floor. The drain tile (from the interior drain) is above
this point. If I unplugged my sump pump, presumably allowing the
water level to rise, would (should, actually) the interior drain below
the basement floor and the exterior perimeter drain begin to capture
the water (I understand the interior drain would feed water into the
sump pit)? I believe the perimeter drain is above that 8" water entry
point-- in its position on top of the footers.

The water table in my area is very high-- reportedly 19" higher than
normal due to excessive precip over the past several months. My sump
pump cycles more frequently after a heavy rain (once every ten minutes
or so), peaking about 12-18 hours after the rain has ended and taking
five or so days to return to a level where it might run once every 2-3
hours, assuming dry weather during this period. I wonder if I am
partially a victim of excessively wet conditions at the moment or is
there something else contributing?

My sump discharge is well away from the house and my gutter downspout
extensions are buried and daylight 20'+ away. The grading around a
couple of portions of the house is not the greatest, but I would have
thought the perimeter drain would capture some/all of the surface
water in these areas (back to my original question).

On a related note, I have considered the idea of having a pipe
microtunneled from behind my property (large hill) under my foundation
and connecting to the bottom of my sump pit. Assuming the technology
is such that the tunneling accuracy would result in the pipe arriving
at the bottom of my sump pit and not somewhere else, I can not think
of any negatives associated with this strategy. It would daylight
down a hill and the sump pump would then essentially serve as a safety
valve in case a critter or something temporarily created a blockage in
the hard pipe.

I appreciate any input related to the number of different things going
on with my particular situation.

Thanks,



--Howie

Howie wrote:
What are the advantages/disadvantages of placing drain tile on top of
the footer vs. next to the footing?


TOP BAD!! been there done that water can and does come from below
footer and work its way thru your basement floor.

the underground drain to daylight is ideal, i would add a perforated
line or two around your basement under the concrete floor for best
drainage if your sump s a single point entry. this also allows drilling
or snaking line ud=nder home to be not perfect location wise.

also price backhoe digging outdoors and run line under floor tearing up
some concrete. you dont necessarily have to get the line to the sump
pit, water finds its own level anyway. just so long as it spills out
from under your home.

daylight drain is the way to go!

Been there went thru this......

It sounds as though you have a near ideal setup. I wouldn't mess with
the basement floor til later if necessary. Your perimeter tile should
be in clean rock at the bottom of the footer. It is best to run clean
rock a foot thick all the way up the wall. This promotes drainage a
greatly reduces any possibilities of problems associated with hydraulic
pressure exerted on basement walls. I have a chart someplace. The
difference in tons of pressure or pressure per square foot exerted on
the basement walls between clean rock & dirt sand or clay fill amazed
me.
The best way is to put landscape cloth down the dirt side of the
excavation so in the future dirt doesn't leach into your clean rock.
Very few homes are built in this manner anymore because most work is
not specced and contractors eliminate this step to cheapen their bid
price.
Also many youngsters learning construction are working for companies
working on bid jobs and never learn that this is the proper method for
back filling.
You've probably seen basement walls that were pushed in? Had they been
properly back filled with clean rock, in all probability they would not
have had that expensive to repair problem.
Tract houses are never built correctly because the contractor usually
only proffers a 1 year warranty and their dirt back fill is not even
fully settled in that amount of time.
I think in your situation that you would be in fine shape if your
perimeter tile was lowered & your house was back filled correctly.
Be sure to check your tile to daylight elevation. You will probably
have to lower that tile in order to drain the lowered perimeter tile.
If your drainage tile has a lot of fall you can slope at a rate of 1/8"
per foot away from your perimeter tile til you hit your drainage tile
elevation.
On my house I installed an emergency sump outside the house. The
perimeter tiles run to the sump & the drainage tile runs away from it.
Thus if my drainage til plugs or becomes overwhelmed the sump pump
helps pick up the slack.

I am wondering what the your gutter situation. Are they properly run
away from the house? I run mine to below grade gutter boxes. These are
open on top with a removable grate for cleaning and overflow water. I
set them about 6' from the basement wall. I then run a tile away from
them to my drainage tile. Actually I have 2 ea. 6" drainage tiles to
accommodate the gutters & the perimeter tile.

Many times water problems can be directly related to poor gutter
drainage.

Another hidden concern is abandoned field drainage tiles. I worked on
one job where upon excavating the perimeter we found a very heavy
source of water. Upon further excavation we found an 8" field tile that
ran towards the house for a 1/4 of a mile. We were able to find an old
tile map that showed the field tile. With some cajoling of the
neighbors we were able to reroute the tile around the home.

Another often skipped step in construction these days is clean rock
below the basement floor. I always put 12" of clean rock & a layer of
insulation under the floor.







wrote:
Howie wrote:
What are the advantages/disadvantages of placing drain tile on top of
the footer vs. next to the footing?


TOP BAD!! been there done that water can and does come from below
footer and work its way thru your basement floor.

the underground drain to daylight is ideal, i would add a perforated
line or two around your basement under the concrete floor for best
drainage if your sump s a single point entry. this also allows drilling
or snaking line ud=nder home to be not perfect location wise.

also price backhoe digging outdoors and run line under floor tearing up
some concrete. you dont necessarily have to get the line to the sump
pit, water finds its own level anyway. just so long as it spills out
from under your home.

daylight drain is the way to go!

Been there went thru this......

Are your gutter downspouts run in PVC unslotted tile or perforated
field tile? If run in slotted tile they could be leaching water around
your house.


wrote:
Howie wrote:
What are the advantages/disadvantages of placing drain tile on top of
the footer vs. next to the footing?


TOP BAD!! been there done that water can and does come from below
footer and work its way thru your basement floor.

the underground drain to daylight is ideal, i would add a perforated
line or two around your basement under the concrete floor for best
drainage if your sump s a single point entry. this also allows drilling
or snaking line ud=nder home to be not perfect location wise.

also price backhoe digging outdoors and run line under floor tearing up
some concrete. you dont necessarily have to get the line to the sump
pit, water finds its own level anyway. just so long as it spills out
from under your home.

daylight drain is the way to go!

Been there went thru this......