# Sump Pump Inside or Out



## colevalleytim (Mar 1, 2008)

Repairing a French drain/foundation drain around a small house (1000 sqft), so i'll be putting in a new sump pump. Any opinions on the pump inside the basement or outside in a covered pit? 

Also, has anybody used a Venturi pump back-up system?

thanks
tim


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## jhark123 (Aug 26, 2008)

I prefer to put them outside in a finished basement and inside if it's unfinished.


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## Frank Castle (Dec 27, 2011)

jhark123 said:


> I prefer to put them outside....


X2

Mine is outside.


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## Fouthgeneration (Jan 7, 2014)

Outside, for the main system, usually in a window well or stoop.

Back up tile looped inside footers to second pit and pump. never connect the two....

running one or more 4" tile into a basement always struck me as SILLY.


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## NJGC (Apr 5, 2014)

Does the house currently get water inside the basement? If so your wasting your time outside. .....the water has already exploited deficiencies in the foundation and it will happen again. Pump and water control system of your choice need to be installed inside. A dual system would be best (inside and out) but the cost is often prohibitive. I spent 7 of my younger years working in waterproofing and foundation repair and I personally would not rely on an outside system to keep me 100% dry.


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## GettingBy (Aug 19, 2010)

NJGC said:


> I personally would not rely on an outside system to keep me 100% dry.


The water level outside and inside is the same unless the basement is watertight, no?


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## dayexco (Mar 4, 2006)

GettingBy said:


> The water level outside and inside is the same unless the basement is watertight, no?


that's soil type dependent. if you have a heavy cohesive soil, i.e., runoff or rainfall can saturate the soil on the top. that water will try and get in through the walls, make it's way down to footing, underneath and through the floor. fluids seek their own level.

if your soil is all granular from topsoil down, and you have a high static water table, yes the water table will be the same inside and out. fluids seek their own level. 

soil types will dictate just how fast that water gets to your pump.

around here now, everybody over digs basement floor elevation by 8", puts in 3/4" crushed rock back to floor slab grade, put tile and at least 3' of rock on outside of foundation and pipe everything to an outside sump which is typically a piece of 12" or 15" PVC pipe on an outside corner of the basement where all the tile goes to, pump is mounted. had VERY good success with these. with proper waterproofing of foundation, water hits the rock, goes into tile, to sump, and gone in a heart beat.


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## GettingBy (Aug 19, 2010)

dayexco said:


> that's soil type dependent. if you have a heavy cohesive soil, i.e., runoff or rainfall can saturate the soil on the top. that water will try and get in through the walls, *make it's way down* to footing, underneath and through the floor. fluids seek their own level.


That must be why a 4" rainfall in one afternoon took the next day to raise my indoor sump level by 2".
Maybe that's also why I have a refill rate of only 1 GPM.

At this rate with a 7' head and with a 100% efficient pump/motor combo [doesn't exist] I'd need a 1 x 7/3956 = 0.002 hp pump, 1.3 watts. With a 10% efficient pond pump it'd be 13w. 
I settled on a 1/6 hp utility pump but the sump remains dry. I may never have needed a pump at all.

But, the lady a few hundred feet up the hill had a flood that reshaped her house so that the doors didn't close anymore. Many kilobucks were necessary to reinforce her basement wall. I guess she could have rented a 100 hp pump if she knew in advance.


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## dayexco (Mar 4, 2006)

yeah, a 1/3/-1/2 h.p. $120 sump pump is a cheap ins. policy against a $1200 big screen and hardwood floors in the man cave.

problem is, most people won't spend the extra money on the things they can't see that are extremely important...to pay for the things they can.


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## Fouthgeneration (Jan 7, 2014)

Any rational housing development has the street storm sewer lines below 99 % of the basement floor levels.... Thus gravity drainage (with back flow preventers & back up interior drains/sumps)

Spending hundreds of dollars yearly to pump water over 7' high man made bump to the street sewers is silly, Gravity is so more reliable than the utility companies too.

Lots(houses) without gravity drainage are rightfully priced ten of thousands of dollars below(the punster strikes!) dryland.

Flood insurance is useless if the underwriter has declared bankruptcy after insuring to many swampland dwellers.

Venturi pumps are an interesting electricity free back up pump(if the city water mains are intact and refilled), and provide safer work areas when one must get in the soup. many are electrocuted when they near electric faults in the muddy waters of floods.

Sadly the more that are sold in a neighborhood, the poorer their performance during a crisis.

don't forget your own plumbing is just as likely to flood your house as the rainfall, washing machine hoses aging, showers leaking, tub overflows blocked, vandels, frost, rusty sewer pipes, plugged gutters, and the dredded ice damns....


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## colevalleytim (Mar 1, 2008)

Oh yeah there is water in the basement.

It's a half excavated basement (not a crawlspace really, more a thin concrete layer over a mound of dirt). The basement is about 76" in height, not legal for a man cave. Just the utilities.

The single downspout was emptying into the foundation drain, then water seeped into the basement. There is no local storm sewer. [although if water dumps into the street, it flows downhill for 2 1/2 blocks to a storm sewer system]

It's a mess really, the house has historic value, was built in 1924, its under 1,000 sqft, and is worth $885K. So it's worth fixing

Currently, there is an internal sump that doesn't seem to be attached to much. But it it is pumping into the sanitary system


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## superseal (Feb 4, 2009)

I run my pumps on the interior,...just seem easier dealing with the maintenance and allows me to monitor issues without dealing with harsh weather conditions and freezing pumps and pipes.


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