I am in a bit of shock after getting estimates from 3 companies to deal with a moisture (and secondary radon) problem in my basement/crawlspace. I found this site while researching for some answers and hope to get more informed.

My house is a ranch that sits on a moderately steep grade. The front of the house is at ground level, and there is a slight overall grade towards the house. The grade increases sharply down the side of the house, and the rear basement is fully exposed to a slight grade away from the house.

The foundation of the house is a combination of two fully separate crawlspaces (with dirt) underneath the front 1/3 of the house and fully finished basement on top of a slab in the rear 2/3 of the house. The side view of the house looks like this (not to scale):

        |  main floor  |
        |______________|
_ground_|crawl|        |  
        |_____|        |
        |dirt |basement|
        |_____|________|_ground_

Top view looks like this (not to scale):
          __________________
          |   |   |        |
  pavement| A | D |        |
          |___|___|        |
              |   |        |
            O |C  |        |
    front ____|___|finished|  back
          |   y|E          |
         x|   y|__         |
     z   x| B     |h       |
          |_______|________|

Crawlspace (A) and unfinished basement areas (D) and (C) are completely dry with no evidence of moisture penetration.

Most of the front of the house is paved except for exposed ground in area (O) and along (x). Drain (z) is for water from the pavement that stops 3-6' (varying) from (x).

I have a personally verified water infiltration problem coming in to crawlspace (B) via the vents (x) that sit below ground level. This occurs in extreme heavy rain when sufficient water collects around drain (z) to overflow into area (x). Area (O) may or may not contribute to this problem.

I plan to install a pond/natural water area in (O), so I will be excavating 1' of dirt in (O) and 1' deep by 2' wide along the wall (x) to add a wooden walkway with a hidden DIY french drain underneath using standard outdoor waterproof liners and gravel/stone. I am hoping this will redirect any overflow water from (z) and eliminate all other potential sources of water on the front of the house.

My first set of questions is, can I DIY this as I intend to, or should I hire professionals? The three companies I consulted indicated that these external measures would help but that the true solution was to install an internal drainage system, so they did not even bother to offer an external waterproofing/draining system.

My second problem is that I have an unknown source of water in (E) that is causing severe efflorecense (y) in the lower 2' of the wall between crawlspace (B) and basement area (E) and leaking localized water into the carpet in (E) (but not extending to area (h) or elsewhere). (B) has 4' of dirt. My thought is that water is entering (B) through (x) and flowing along the wall adjacent to (O) and collecting around (y). All 3 companies suggested that the water source is underground due to the efflorencense along the bottom 2' of the wall instead of 4'. Nobody has actually bothered to crawl into (B), though they did look into (B) from location (h).

All three companies are suggesting that I install an internal french drain system in (B) with a sump pump, approximately 100' around the perimeter, at costs ranging from $4000-7000 depending on options (higher end includes air extraction to dehumidify and remove radon gas). One company is suggesting a full-house internal french drain, moisture barrier panels, and air extraction covering all below-grade walls (430' spanning 3 sides of the house along the basement and crawlspaces) at a cost close to $19,000 to address both my water and radon problems.

My second set of questions is, are these costs reasonable, and will these methods actually solve my problems? If not, what alternatives do I have? All three companies came highly recommended, and one is a nationally recognized franchise.

Your drawing is not very clear, but your issues are.
No internal system is worth the money. Unless you simply want to allow the water to enter the house, then pump it back out again. With that you will need to dehumidify the crawls and basement as the humidity levels will raise as you allow the water to enter.
The signs of efflorescence are an indication that water has reached this area, even if you have not seen it its there.
The radon system will need to be installed by a professional licensed radon mitigation contractor. While venting may help lower the readings, only licensed contractors may install these vent systems.
Because you have what is called a Bank house. Ranch in front two story in back. The water proofing system will end up being U shaped to wrap around the house.
Of course anything you do on the outside may help slow the progress of water entry, but it will not cure it.
You must dig the outside of the house and properly repair any cracks in the exposed foundation walls. Seal with asphalt, cover with heavy plastic. Place a drain pipe around the house going to the daylight on each side and back fill with pea gravel. With top foot or so with fresh clean soil.
AS far as costs. Everything is going up because of the price of oil going up. I have seen a 23% increase in asphalt coatings just in the past month. So the estimates your getting are pretty much in line. the $19,000 job. tell the person to have a nice day and lock the door when he leaves. Even it the company is nationally known. Your paying for the franchise fees, and all the ads placed in papers, yellow pages, radio etc.

I agree that the best way address any moisture problem is to prevent it from entering the house in the first place.

It is clear that water is entering through the below-grade ventilation ducts (I have seen it), but it is not clear that there are any external foundation cracks. Of course, the only way to know for sure is to dig and inspect. Or perhaps I can attempt to saturate the ground with a garden house without causing overflow into the vents, then see if there is any moisture in the crawlspace.

It is difficult to dig the full U perimeter of the house. There is a concrete walkway against the wall down one side of the house that is dry, and most of the front of the house is paved up to the foundation except for area (O) and the strip along (x), so it is not surprising that the rest of the basement and second crawlspace are dry.

But my main problem is that no waterproofing company I found in central NC is offering to do an external solution. Should I seek out foundation repair companies and ask to dig, repair and seal instead?

Regarding estimates, are you saying that the $4,000-7,000 is in line or that $19,000 is in line?

Finally, the combined $19,000 water/radon system was quoted by a licensed radon mitigation company to address a 6.5 basement reading observed after a rainy day with HVAC off. I am talking to other radon companies, but I fear that each proposed solution will be different and have to wonder what will actually fix my problem at a reasonable cost.

concrete walkway,drive-patio`s,decks are not a problem, least not from where i sit. Have done many over 30 yrs, if existing concrete is in good condition then we`ll saw-cut approx 18-20" wide by whatever linear footage and knock out in order to hand dig,waterproof-backfill correctly.Just so you-others know.

many inside co`s use this(concrete etc)as a way to BS people into an inside system, among other misrepresentations/false claims.

not all cracks on EXTERIOR of block walls are visible from inside basement/crawls.Many HO`s have NO visible cracks inside the basement yet have vertical/step/horizontal cracks on exterior. Won`t see possible cracked/loose parging either.Won`t see gaps-spaces around service lines and most often won`t see gaps-openings under bsmt window sills or just underground along brick ledge.

Just because some don`t know, can`t see these cracks/openings doesn`t mean they don`t exist. Have posted many pic`s of various exterior entryways.

Find-locate any-all exterior openings and repair em correctly. Some HO`s who have crawls w/dirt floor simply need a concrete floor.Bottom line, find where water/moisture/insects are first-entering. Sometimes it takes a lil patience.

Here some pics http://www2.snapfish.com/thumbnailshare/AlbumID=2282761...1847456/t_=122238283

1-13 vertical crack,old gas line that wasn`t repaired completely(hydraulic cement etc), open mortar joints. Can ya see how termites,centipedes,carpeneter ants can enter? The crack and hole are not visible from inside basement, its how many HO`s get fooled,talked into blllcrap inside systems.

How about here.. http://www2.snapfish.com/thumbnailshare/AlbumID=2165326...1847456/t_=122238283

Most cracks on exterior are NOT visible inside basement. Neither are any of those open joints.

Expanding-contracting soil and roots against exterior wall. Only way to get this crap OFF wall is on outside. Only way to stop-prevent further water/insects from entering these openings is outside.

An inside system was installed here, walls were recently painted. Water-moisture STILL entering because the REAL problems were/are outside...cracks and other exterior openings. So,mold or mildew,efflorescence,paint peeling still occurring. Insects still have their pathways into home/basement. http://www2.snapfish.com/thumbnailshare/AlbumID=2198255...1847456/t_=122238283

Again, cracks on outside are not visible inside basement.See cracks, then see pics 10,11 inside. http://www2.snapfish.com/thumbnailshare/AlbumID=2165904...1847456/t_=122238283

This HO in Eastpointe MI had a back porch,footing, steps at back door, no problem.
Had estimates from $20,000-24,000 ish.
Job was done for around $7,700...or something very close to that number, been awhile.HO also had central air on back wall, no problem. Not much room on one side of house, no problem. Last couple pic`s...see lost of ruined landscaping? Hardly. Expensive? An inside co. wanted the most, $24,000 and would have dug a shallow...1-2' exterior trench,put drain tile in it,put 1-2' dirt back and put in inside system...$24,000. What cost more, Inside or honest-outside contractor? http://www2.snapfish.com/thumbnailshare/AlbumID=2165857...1847456/t_=122238283

This message has been edited. Last edited by: LicensedWaterproofR,

To add to the excellent responses you have already received, I won't ask if the contractors you've spoken to have done a simple hose test to find where the water is entering, because I know the answer. You can find good instructions on how to do this in previous posts by LicensedWaterproofer or LicensedWaterproofR (same dude different nicks). Have some patience when you do the test...take a couple or three days, but when you're done, you'll have your answer. Did anyone suggest placing areaways around those vents to keep the water away from them?

I appreciate everyone's helpful responses. I am less surprised about the lack of a hose test and more alarmed that these contractors never bothered to crawl into the crawl space to inspect the walls with the moisture problem. I suppose that the clean suits and ties worn by the inspectors should have been an obvious hint.

After some more phone calls, I did manage to find a waterproofing company who actually explained both methods and suggested that external waterproofing was the preferred method, so I will see what they have to say about my particular problem.

As for the area ways around the vent, I am hoping that my plans to capture and redirect water before it reaches the external walls through a drain system will help.

I wonder if the recess in Area O is catching ground water flowing down the hill and allowing it to collect there, causing elevated hydrostatic pressure on the wall of the recess.

I don't know when the house was built, but it may not have been dampproofed correctly, or the dampproofing may have been compromised by incorrect backfill (rocks, construction debris) ot tree or shrub roots, causing a leak in the wall. However, dampproofing isn't waterproofing, and it's not intended to hold back high hydrostatic pressures. Only a membrane of some sort will do that.

It seems like you're on the right track now, with a contractor who may know what he's doing. Good luck!

quote:

Originally posted by LicensedWaterproofR:
concrete walkway,drive-patio`s,decks are not a problem, least not from where i sit. Have done many over 30 yrs, if existing concrete is in good condition then we`ll saw-cut approx 18-20" wide by whatever linear footage and knock out in order to hand dig,

18"-20"? Gotta tell you LWP, you gotta bigger ones than me to crawl in a hole that wide. Ever have one callapse on you?

What needs to be done on the vent area is a small window well system out of brick needs to be constructed. On the bottom of this a pipe leading to the gravel that is placed against the house wall when the outside system is installed will do the trick. This will prevent any water from filling up and overflowing into the vent.

Jay,

yeah well, it all depends on depth to footing and type-of-soil that we`re digging in and the amount of water in the soil(if its rained a ton recently etc)

since most jobs we do are between 5 1/2-6 1/2' deep and 3 outta 4 are clay then yep, anout 18-20" wide(have posted quite afew pic`s,should be able to see the width). sand-silt would be a lil wider and wider than that if its 8-12'deep.

yes,sure,absolutely have had some cave ins over the years. when builders backfill w/lots of crap like bricks,blocks,wood etc, this alone can cause cave-in, especially when its right along the bank side,next to where we are digging.gotta be aware of all these(and other) factors when digging underground.

usually its 1-2 cave ins a year. some years we may have none and others might have 4...just depends.when we are digging in chtt soil, we know within the first 2-3' if there is possible trouble and if so, we`ll dig it wider and/or step the trench down.

Or say we`re digging one 30' wall in one day and see its a possible cave in, what we`ll do is is dig it wider then divide the 30' into 6' to 10' sections and dig one section down, waterproof it, backfill about 2' or so, then dig another section down and do the same thing,waterproof and backfill. At this point we have 1/2-2/3 waterproofed next to each other and can backfill more to hold up the bank, then dig the other lone 6-10' and finish.This has saved quite a few cave ins.

Again, we all need to be very aware of the soil,the amount of water in soil,if builder backfilled w/tons of crap,service lines etc etc etc.It all dictates how trench will be dug.

Have seen quite a few contractors and some DIY`ers have many cave ins, they either don`t know or care about what i just said. Have seen quite a few contractors use shores....it didn`t prevent cave ins. When i stared in this business long time ago, we shored the banks on some jobs too, did not prevent cave ins.Not at all saying shores can`t help or give someone a few extra seconds to get outta hole. Just saying we all need to be very aware,every day,every job and be ready to make changes if necessary. Even when taking precautions and knowing the soil,shoring etc a trench could cave in. We are always on the 'look-out', constantly, throughout the excavation and waterproofing.

A follow-up with questions...

Thank you for the informative answers. With the aid of an environmental consultant (water, mold, etc), I spent half a day examining the crawl space, roof, gutter and drainage system with the "water hose" test, and the conclusions to a reasonable certainty are: 1) main cause is stoppage in drain (z) causing overflow through vents (x) into the crawlspace (B) and saturation in area (x) causing secondary seepage through the foundation wall; 2) tertiary cause is likely the ancient terracotta drain pipes for the gutter system contributing to the water saturation along (x).

The proposed solution, to be carried out by a general contractor, is as follows:

1) Excavate (O) and (x) and around the side of the house down to foundation, ~4' deep
2) Patch any foundation cracks and seal with asphalt.
3) Install sealed roofing rubber membrane spanning (O) and up the foundation walls around (O), like a swimming pool, and along (x), with the bottom sloped away from the foundation.
4) Install perforated pipes around the perimeter of (O) and along (x) to drain down the side of house
5) Backfill to 2.5' depth with washed pea gravel
6) Install new drain pipes for gutter system around (O) and along (x) to drain down the side of the house
7) Backfill to 2' depth with washed pea gravel
8) Install pond membrane in center of (O) with 1' gap to foundation
9) Backfill the gap around (O) and along (x) to grade with pea gravel

Any water in (O) (including pond leak), overflow from (z) and along (x) would go down the gravel, be collected by the rubber membrane and be drained by the perforated pipes. Any water from membrane failure would have to seep past the new asphalt waterproofing in the foundation.

My questions are:

1) Are there any obvious problems to this approach?
2) 20 tons of gravel will sit in (O) and (x). Do I need to be concerned about structural integrity?
3) I would like to add external foundation insulation in the form of foam panels between the wall and membrane but am concerned about termite access. Any insight?

Thank you.