Lowest point for a sump - what does that mean?

[Eliza Fletcher]

I want to install a sump pump and partial interior french drain to address water problems. My house sits on a hill. I keep reading that it's best to locate the sump at the "lowest point" of the foundation, but I don't know what that means. Does anyone know? Is it A) the point where the foundation slab is deepest down in the ground (which would be at the top of the hill) B) the corner of the slab that is at the bottom of the hill; or C) The low point on the basement floor itself (ie, the spot a ball would want to roll to)? Thanks

[Robert J. OConnor]

http://www.nachi.org/forum/f23/moist...sements-63259/

[ROBERT V. YOUNG]

The lowest corner of your slab.
Low part of the basement.
Why partial interior sub drainage? Did a drainage firm ( foundation drainage engineers-contractor evaluate hydrostatic pressure in certain area under your foundation slab that can not be addressed from exterior French or sub-drainage?
Sub drainage is the proper name.
French drain is Americanized name.
http://www.foundation-repair-guide.c...nch-drain.html

[Jeffrey R. Jonas]

Eliza,
I read your other thread the other day. I have one piece of advice now that I have read this thread... call in an expert. You are in over your head (excuse the pun). Before you start throwing money at a problem, you must first determine the actual cause of the problem. If not, you will literally throw money down the drain (!) hoping you will get lucky. Spend your time researching who to call, not what the fix may be. The local AHJ is fine for basic legal information, but is useless to diagnose a situation. It may very well be multiple fix'es to repair your problem. Leave it to the true professionals. Perhaps if we knew your location, we could help guide you in the right direction. Good luck.

[ROBERT V. YOUNG]

Great advice Jeffery.

[Eliza Fletcher]

Rest assured that I will have multiple experts look at it. I just like to be very informed so I can tell the "experts" from the experts. This is just one bit of my research. I still don't know what the "lowest" point means as it could mean any of three things per my first post. What does that actually mean to you? The slab itself is level like most, so I don't see how that could be what is meant by this.

[ROBERT V. YOUNG]

Originally Posted by Eliza Fletcher

Rest assured that I will have multiple experts look at it. I just like to be very informed so I can tell the "experts" from the experts. This is just one bit of my research. I still don't know what the "lowest" point means as it could mean any of three things per my first post. What does that actually mean to you? The slab itself is level like most, so I don't see how that could be what is meant by this.

The lowest point of the sub drain entry.
If it is level then its inches that will make the decision. Leave it up to the experts. Lazar level will detumin the exact point for placement.
Good luck.
Keep us posted please.

[Robert J. OConnor]

For an interior french drain system the pump should be located in a pit at the lowest point of the basement slab, with a perforated drain running around the entire perimeter.

But an interior french drain system should be one of the last resorts as it actually encourages water to enter your basement, and will not work if there is a power outage during a severe storm unless there is battery backup or a backup generator. For most situations it is a very poor band aid solution.

Read the thread noted above, and have an independent specialist look at the situation (not just a waterproofing company) before you possible waste a lot of money.

JMO & 2-Nickels ...

[Roy D. Cooke, Sr]

Originally Posted by roconnor

Read the thread noted above, and have an independent specialist look at the situation (not just a waterproofing company) before you possible waste a lot of money.

JMO & 2-Nickels ...

I have a sump pump runs in November and April .
Being on town water I put in a water powered pump, does a great job in a power failure ,Cost about $100;00 at Home Depot..... Roy

[Robert J. OConnor]

Originally Posted by rcooke

I have a sump pump runs in November and April .
Being on town water I put in a water powered pump, does a great job in a power failure ,Cost about $100.00 at Home Depot..... Roy

I haven't come across one of those yet, but it sounds like a good idea for a last resort ...

[Roy D. Cooke, Sr]

I also lowered the pit so pump comes on and keeps the water below the floor by at least 12 inches.
This has lowered the humidity in our basement big time and the dehumidifier seldom runs any more..Roy.

[ROBERT V. YOUNG]

New systems or should say materials.
The sub drainage piping inside and outside of the footing. Both connect to the sump.
Attachment 48415

[Roy D. Cooke, Sr]

Quote:
Originally Posted by rcooke
I have a sump pump runs in November and April .
Being on town water I put in a water powered pump, does a great job in a power failure ,Cost about $100.00 at Home Depot..... Roy

Originally Posted by roconnor

I haven't come across one of those yet, but it sounds like a good idea for a last resort ...

http://www.costco.ca/Browse/Product....153&lang=en-CA

[ROBERT V. YOUNG]

Excellent price Roy.
Great systems.
Introduced to water sub drainage system 7 years ago.
After the 1998 Quebec ice storm.
Owner said it was $2200 for pump + licensed installation and warranty.

[ROBERT V. YOUNG]

I also lowered the pit so pump comes on and keeps the water below the floor by at least 12 inches. This has lowered the humidity in our basement big time and the dehumidifier seldom runs any more..Roy.
Roy I could not agree more. Most foundation problems are man made installation error.