Odd, thought I had mad a lengthy post here, but must have been a different forum, about a week ago. So here goes...Bought a ranch brick on a crawl, Indiana clay soil. Issue is because of code, rather lack of, no perimeter tile was put around footer. Being that the elevation is darn near flat of back and sides (front does have a nice slope to street) when it rains the water settles around perimeter and seeps into crawl. Also, because of "lack of" code, the sump pit, located in one corner, is just a pit with some weep holes. No piping run into the pit, to rid of any water. There is water under the crappy plastic in some areas over the pea gravel. This is an unhealthy environment for the TGI trusts, obviously. I don't like the idea of water submerging my concrete footers. So the house has been this way for its 10 yrs age. To remedy this, I can either #1, reposition the sump pit more mid of of crawl, dig in some drains, which because the support structure footers also, run the entire length of crawlspace, a company would have to undermine the foots for a 4" pipe in at least 3 different places to get the water to the pit, then have to have the sump most likely running frequently, and always the chance of it failing, and so-forth. #2, have a perimeter pvc pipe layed level on gravel, just below the footer of exterior, and having it drain to daylight at front of house near street. "Most" of the foundation for crawl footer would be able to be accessed. They would also powerwash and seal the 8" blocks to prevent any more seeping. The downspouts would also be connected in pvc and ran separately to front. I have all but ruled out, there is hydraulic pressure pushing water into the crawl as a basement was just dug directly next door. It sat for a week and stayed dry. So to me, dealing with putting the fix in the crawl, is just masking the issue, which is water is coming in from outside. It'd be roughly, another $2k for the exterior tile. Either are salty as is mostly labor intensive. This will be hired out (that point isnt for discussion) I then will encapsulate, sometime next year to keep this high humdity pit, from eventually rotting the wood. Any opinions here, on my 2 remedies, and which you would do? I have given this much thought and have a few crawlspace doctors have a look. They all wanted to fix from the inside. (how they make their $) My 1st gut instinct (and one other contractor/builder) came immediately to the conclusion...repair from the outside and drain to daylight.

 

Outside sounds like the right approach to me, especially with no evidence of high water table. Just keep in mind that when you say "just below the footer of exterior" that you cannot undermine the footer at all when digging, and should not even dig straight down at edge of footer. At most you can dig at a 45 degree angle from the bottom of the footer. That should not be a problem for your plan, but you want to avoid an overzealous equipment operator digging too deep, too close to footer.

 

Perimeter drain pipes/tiles just outside the foundation footings are slightly better than the same just inside the footings although for most homes with basements the inside pipes/tiles are easier to retrofit.

Sealing the foundation walls is better done on the outside although it may be much easier to do the insides instead. Sealing the walls is desirable so water won't find it easier to seep through the walls or any cracks therein compared with seeping down to the drain pipes/tiles.

When putting in perimeter drain pipes/tiles it is not necessary to move the sump pump pit to the middle of a wall. Moving the pit to the middle of a wall and not installing drain pipes will accomplish almost nothing; you will protect the area around the new pit location from seepage to the surface but will lose the protection in the pit's former location. Do not move the pit to the middle of the crawl space or basement, away from all walls.

If the land is so darn near flat then you need to regrade around the foundation so water runs away, even if there is a gradual dip bottoming out fifteen or so feet away from the house and a rise back to former level (called a swale).

There is almost never a need to dig below the level of the bottoms of foundation footings.

You can get away with little or no slope of the perimeter drain pipes to the sump pump pit provided that when the sump pump empties out the pit, there is no point back in the drain pipes where enough water stays behind to completely fill the pipe. This goal will be met if there are no dips (bellies) and no reverse slope anywhere in the drain pipes along the way to the pit and the sump pump (or gravity drain) never lets the drain pipe ends as seen in the pit become completely submerged.

 

Carbide...yes I did not mean to sound like undermine. Either person I have spoke with have done several outside perimeter. One of my concerns of one guy wants to lay the black corrugated on pea gravel, with no fab. The other guy, I stated in quote itd be the pvc with the holes near bottom, with washed stone, and fabric. He would seal the block, as well as put up a drip board to block. Also would have a couple different areas for future cleans out. Both quotes about the same price. I like the drip board gut quote better.

 

Allanj, unfort., can not regrade. You'd have to see it. This is not an option. I understand what you state about the pump pit. Will say, it's about a 70' run from pit current location, to opposite side, where there is a bit more water located. One guy (I think all about the money...and I had been warned of this specific statement, by another interior drainage guy) stated...."you will need about 1/8" fall every 10' to the pit. The end of the pipe would be below the pit bottom if you had to run 70'. I responded...the pipe does not need to have fall and that the water would find it's way to the pit. At that point I knew he was FOS.

 

I will also add, my only concern with exterior, is that there is about a 10' section in front of house which will not get exterior drain, due to front porch area and a sidewalk, as well as garage. I don't really see this as a huge issue, because I feel that any water gather there, would eventually, (hopefully) get into that exterior pipe, and drain away...or, jump simply seep into the earth.

Also, before I would encapsulate (after exterior pipe) I will keep an eye on what is going on down there and "possibly" add a couple lengths of tile to get any extra water out of there, which theoretically, there should not be any...

 

It is possible you may want to dig a second pit at a corner if the footings are lower there compared with at the present pit location. (The first pit could be kept for an auxiliary sump pump if you have had problems in the past with the pump unable to keep up.)

Ideally the pit should have at least 3 cubic feet (about 20 gallons) worth of space below the drain pipe ends and not filled with gravel or rocks. Most pit liners (basins) are too small for this but it is possible to build a pit using bricks. With the 3 cf pit you do not need a check valve in the sump pump outlet pipe and also there is time for more water queued up in the drain pipes to pour into the pit and be expelled before the pump shuts off.

Ideally the pump, once it starts, should keep going until the pit is nearly empty. In a few cases a fraction of an inch of water has to be left behind to prevent sucking up dirt and shortening the life of the pump. Some sump pumps don't have a float with enough range to do this and installing a separate float switch system (sold separately) might be desirable to go with that model of pump.

 

Is that fabric necessary on that 4" rigid pipe, on #4 stone....or just a waste of $$$?

 

I put the fabric in the trench first, then stone, then pipe, then more stone, then wrap the fabric back over the stone before backfilling. The fabric keeps dirt from washing into the stone and blocking the drainage paths between stones. I also put a lot more stone in than most....up to about 1 foot below grade. It can be a lot of stone, but you want any water that makes its way into the area to quickly flow down into the drain.

 

Carbide, thx for the tip. I will have it accomplished the way you described. I have read it done this way as well. The dig will be approx 4' deep and around 200'.

 

Fabric or "socks" can cause problems on smooth rigid drain tile or pipes. The fabric can cling to the pipe and just the half inch or so circles worth of fabric directly over the perforations will pass water and will clog much more quickly compared with large expanses of fabric hanging loosely.

The clinging problem can be alleviated by putting down just a thin layer of stone or gravel, then putting down the fabric, then putting down another layer of stone, then putting down the drain pipe and wrapping it, stone and all, with the fabric.