# Crawlspace low point drain details Pacific NW



## Golden view (Feb 16, 2012)

Here they put a piece of 3" abs with a backwater valve through the footing, but this is new to me since I learned foundations on another region. Does it go at the bottom, under, or middle? Dumb question I know but I'm new to the practice.


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## greg24k (May 19, 2007)

Golden view said:


> Here they put a piece of 3" abs with a backwater valve through the footing, but this is new to me since I learned foundations on another region. Does it go at the bottom, under, or middle? Dumb question I know but I'm new to the practice.


It usually under it with a sleeve. If you going through the footing you have to make the footing is thick enough to have a min 6" of concrete above the sleeve.


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## Golden view (Feb 16, 2012)

greg24k said:


> It usually under it with a sleeve. If you going through the footing you have to make the footing is thick enough to have a min 6" of concrete above the sleeve.


I'm 80% sure they don't do it your way, even though your way makes sense.


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## greg24k (May 19, 2007)

Golden view said:


> I'm 80% sure they don't do it your way, even though your way makes sense.


I don't know how they do it, stop by and see what they say. This was always a typical way of doing it, the sleeve would be wedged between the form, you would dig a bit deeper under it to make sure entire sleeve is embedded in concrete and after the forms off, you slip perforated pipe and tie into the pit something like this. There is also a code section about that.


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## Golden view (Feb 16, 2012)

Typical crawlspace here has footing bottom at the same elevation as crawl floor. No gravel or drain tile inside or out. I'm pretty sure most of them have this low point drain just sticking through and shoved into the dirt. If nothing else it gives you an easy connection point down the road to add a drywell.


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## Seven-Delta-FortyOne (Mar 5, 2011)

Why do they have the interior crawlspace at the same level as the footing?

Why would someone _intentionally_ bring water into the crawlspace, and then pump it out? :blink:

And I've always thought that sleeves had to be in the stemwall, or below the footing? I'll have to look it up sometime, but I'm pretty sure there is a code prohibition about penetrations through a footing.


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## Bull Trout (Dec 6, 2016)

One way valve to allow water out without having to be pumped, as the water table rises the pit will fill higher triggering the pump


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## greg24k (May 19, 2007)

Seven-Delta-FortyOne said:


> Why do they have the interior crawlspace at the same level as the footing?
> 
> Why would someone _intentionally_ bring water into the crawlspace, and then pump it out? :blink:
> 
> And I've always thought that sleeves had to be in the stemwall, or below the footing? I'll have to look it up sometime, but I'm pretty sure there is a code prohibition about penetrations through a footing.


Plumbing pipes for a sewer connection or water lines cannot go through footing it must be under or through a stem wall.
Like the house I was building in the picture 1you can see sleeve is going through the stem wall, after the backfill, when they bring water and sewer, all they have to do is slip the sewer and water lines through the sleeves.
The second picture is incorrect, they have a perforated pipe running right through the footer, there should be a sleeve installed.
The 3d picture is how it's done, you put a sleeve and when doing the drain pipe you slip right through.


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## Mordekyle (May 20, 2014)

Golden view said:


> Typical crawlspace here has footing bottom at the same elevation as crawl floor. No gravel or drain tile inside or out. I'm pretty sure most of them have this low point drain just sticking through and shoved into the dirt. If nothing else it gives you an easy connection point down the road to add a drywell.




That is how it seems almost all of them are here in Salem.

Not always at the low point. Generally at the dirt or an inch low or high. 

They don’t always have the check valve.

They generally run to the curb. Sometimes to a greenway if there is one at the back of the house.

Just about always through the footing.

It does make for a handy place to add discharge for a sump pump.






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## fjn (Aug 17, 2011)

It has NEVER made sense to me to "invite" exterior ground water into the structure only to then have to figure out a way to get it back out ! Having an exterior and interior footing drain system tied together also makes no sense. If one wants to have two systems,great,let the interior on be thought of as the back up system.

The answer to all this is an exterior sump basin. JLC ran an article on that a few months back. FHB showcased it in their book called best practices. I will see if I can pull one up.


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## fjn (Aug 17, 2011)

https://www.jlconline.com/how-to/foundations/q-a-sump-for-foundation-drain_o


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## Mordekyle (May 20, 2014)

fjn said:


> It has NEVER made sense to me to "invite" exterior ground water into the structure only to then have to figure out a way to get it back out ! Having an exterior and interior footing drain system tied together also makes no sense. If one wants to have two systems,great,let the interior on be thought of as the back up system.
> 
> 
> 
> The answer to all this is an exterior sump basin. JLC ran an article on that a few months back. FHB showcased it in their book called best practices. I will see if I can pull one up.




The check valve stops water from backing in as well as rodents from getting in.

They seem to work fairly well. They are not tied to rain drains, but separate

A lot of the soil around here has a lot of clay in it. It would take a long time for it to migrate to an exterior sump pump.


.



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## fjn (Aug 17, 2011)

Mordekyle said:


> The check valve stops water from backing in as well as rodents from getting in.
> 
> They seem to work fairly well. They are not tied to rain drains, but separate
> 
> ...






That is totally besides the point. Why invite it in only to pump it back out ? A pump malfunction,power outage and wham O water filling up inside. Makes absolutely no sense. Keep it outside at all times ....where it belongs !


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## greg24k (May 19, 2007)

What you basically doing is releasing hydrostatic pressure from the foundation or having the water build up alongside of the wall, this is a system which allows the water enters the sump pump and it pumps the water out to the daylight.
It was designed that way and it works.


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## fjn (Aug 17, 2011)

greg24k said:


> What you basically doing is releasing hydrostatic pressure from the foundation or having the water build up alongside of the wall, this is a system which allows the water enters the sump pump and it pumps the water out to the daylight.
> It was designed that way and it works.





Yeah,it works alright...........until it doesn't as in failed pump,power outage.

An exterior sump pump or better yet,pipes run to daylight (gravity never fails us ) will do all your system will do with none of the risk.


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## greg24k (May 19, 2007)

fjn said:


> Yeah,it works alright...........until it doesn't as in failed pump,power outage.
> 
> An exterior sump pump or better yet,pipes run to daylight (gravity never fails us ) will do all your system will do with none of the risk.


Today most people I know have battery back-up pumps, after Sandy and Katrina, people been hooking up generators. battery pumps, etc.

This is a pretty common practice in Jersey for every new built... if you have or believe in a better system or you have a different requirement in your area, you can put exterior pumps, etc whatever works my friend.:thumbsup:


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## 91782 (Sep 6, 2012)

Sump pumps are a necessary evil. I don't know what folks with basements did before sump pumps came along. Bailed after every rain storm I guess.


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## Seven-Delta-FortyOne (Mar 5, 2011)

SmallTownGuy said:


> Sump pumps are a necessary evil. I don't know what folks with basements did before sump pumps came along. Bailed after every rain storm I guess.


Depends on the area.

Here our water table is deep, and terrain in mostly hilly. 2 wells at the ranch are both 125'. 

Lots of walkouts. Easy to keep dry with proper damp-proofing, and backfill with good quality drain rock, and filter fabric.

I don't envy you guys building where the water table is a couple feet. :no: :laughing:


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## greg24k (May 19, 2007)

Seven-Delta-FortyOne said:


> Depends on the area.
> 
> Here our water table is deep, and terrain in mostly hilly. 2 wells at the ranch are both 125'.
> 
> ...


Have to keep the basement floor above the water table min 1'. As you can see in the first picture I posted, I could only go 40" +10" footing because of the high water table.


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## 91782 (Sep 6, 2012)

Seven-Delta-FortyOne said:


> Depends on the area.
> 
> Here our water table is deep, and terrain in mostly hilly. 2 wells at the ranch are both 125'.
> 
> ...


yup
If sump pumps were disallowed in the Detroit metro area - well, there would be no basements.


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## Big Johnson (Jun 2, 2017)

Every site is different, when you dig the hole you have to determine if that basement will need a sump and pump and footing drains or not. It’s been about 50/50 for me.


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## 91782 (Sep 6, 2012)

Here: Gravity or sump pump assisted - We must have one or the other.

I have zero builds with gravity systems.


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## fjn (Aug 17, 2011)

SmallTownGuy said:


> Sump pumps are a necessary evil. I don't know what folks with basements did before sump pumps came along. Bailed after every rain storm I guess.




Well John,this is what they did in the rural areas. They built on the high ground and let gravity do it's thing. Around here N.W. Indiana,you can drive past any old farmstead and see where the house was built,it was the highest portion of the farm. I don't care if that high place was 10 ' from the road or if it was 700 ' ,that is where the house went.

Determining how to address the water management concerns during the basement and excavation portion of the job is the incorrect way to attack the situation in my not so humble opinion. That should be looked into before the yellow iron ever pulls up to the site. There have been several article that warn / implore builders to do soil testing on every lot in the subdivision. It is prudent and rather inexpensive to do them all while the equipment makes one trip rather than piecemeal. A good developer will spend that money up front to assure that each lot is truly shovel ready.


I have seen developers literally go bankrupt trying to save a few bucks. A long standing developer by me developed and area with questionable soil. Several years later,much settling was taking place;it was determined the homes were build over a bog several feet below the clay soil beneath the footings. The cost to install helical piers was over 75 K for each of the homes,and that was over 20 years ago.


We now have available testing methods that can ALMOST take the risk out of the unknowns,it is prudent to avail ourselves of this technology.

If the lots show a high water table,the idea of a full basement probably should not be in the cards. 


Bottom line,I'm not against sump pumps,all I'm saying is place them outside,in the event of a problem,you have bought yourself a tad more time.


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## Golden view (Feb 16, 2012)

Pumps are rare here. Generally they tie to the storm sewer or go to daylight.


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## fjn (Aug 17, 2011)

Golden view said:


> Pumps are rare here. Generally they tie to the storm sewer or go to daylight.





That is very interesting and makes sense.

Just some trivia,I have an long term friend in the area whose family were some of the very first settlers in the area. My fiend who is 83 yrs old has been an excavating contractor his entire life. One of the very best machine operators I ever knew. He is a guy with so much knowledge of soils in the surrounding area,he can tell you with assurance what you will hit when yo did at what season of the year. Several years ago,he said 60 % of the remaining undeveloped lots in the county were not fit to be built upon. At that time,I thought his assessment was rather harsh . Now,I look back and realize if he was wrong,it was because he was on the low side.

When less than prime locations are developed,that is when issues pop up that impact the buildings for the duration.


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## 91782 (Sep 6, 2012)

fjn said:


> Well John,this is what they did in the rural areas. They built on the high ground and let gravity do it's thing. Around here N.W. Indiana,you can drive past any old farmstead and see where the house was built,it was the highest portion of the farm. I don't care if that high place was 10 ' from the road or if it was 700 ' ,that is where the house went...............
> 
> .


Yup. How my parents old farmstead was built. Those days are long gone. Like 150 years long gone.

I spent nearly 20 years building on the largest ex-gravel pit operation in the state. Some places you can drill 250 ft and still get gravel on the core bit.

Doesn't matter. Every basement got a perimeter tile and sump. We're gonna spend the dime. If HO wants to do something after - so be it.


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## fjn (Aug 17, 2011)

Just thought I'd share this first hand experience why soil borings are extremely beneficial PRIOR to laying out the strategy for a new building and before the yellow iron is on site. 

I'm located about 3/4 of a mile due south of the south shore of lake Michigan. From the shoreline inwards for the first 1 / 2 mile pure sand about as far down as you would want to dig. That sand is very fine grained but well drained. after that first 1/2 mile and about 4 miles south,the top soil is hard pan clay for the first 6 -8 ' then extremely coarse well drained sand.

So,the newbies that are not aware of that,do the typical footing drain pipes ,sumps the whole nine yards. The option is if you know the soil you are up against,you still do the drain pipe etc. however,in strategic locations in the SDR 35 drain pipe,you install a 4 way T over holes and pipe you have bored down 2 feet or so to the well drained sand. One part of the T is ran straight up to grade and capped off. From that point forward,little if any water ever makes it to the sump basin. The reason for the pipe and T to grade,all it will take is a minuscule 1/4 " of clay silt to migrate down to the sand and seal it off. When one discovers their sump pump has been running,just pull the cap and poke down a tad with a sharp stick and you will be in great shape for several more years.


For those who never had soil borings and are unaware,they wrestle with what comes with pumps,electric outages etc. for the life of the building.


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## Fouthgeneration (Jan 7, 2014)

The sleeve in the footing to allow the basement to FILL with water in flood so the walls of the basement aren't blown in by the liquidfied soil,

A wet basement, much better then a destroyed foundation.

Don't keep pumping when the yard is Under river water....:sad:

Agree with FJN, install primary sump pump in a window well or Fruit cellar/vault room with a raised threshold/kneeknocker. Secondary one on interior loop of tile, cross connected with a plunger style valve for Noah floods.


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## Big Johnson (Jun 2, 2017)

fjn said:


> Just some trivia,I have an long term friend in the area whose family were some of the very first settlers in the area. My fiend who is 83 yrs old has been an excavating contractor his entire life. One of the very best machine operators I ever knew. He is a guy with so much knowledge of soils in the surrounding area,he can tell you with assurance what you will hit when yo did at what season of the year. Several years ago,he said 60 % of the remaining undeveloped lots in the county were not fit to be built upon. At that time,I thought his assessment was rather harsh . Now,I look back and realize if he was wrong,it was because he was on the low side.
> 
> When less than prime locations are developed,that is when issues pop up that impact the buildings for the duration.



I guess if you, your friend and the democrats have your way this is America’s future:


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## ncizjp (7 mo ago)

I'm not an expert in this matter. I came to this forum to ask similar stupid questions. I liked the answer of the first commenter. I didn't even know that I should create a sleeve there. I thought that simply pouring the pipe with concrete would work in any situation. I should probably hold off on that and turn off the water in my old house. I have to go there this weekend to fix the drainage problem. My friend said that I don't have to puzzle over it and that I should contact a professional from https://draintoronto.ca/drain_camera_inspection. I thought about hiring a contractor, but that's not a suitable specialist.


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