Water in my crawl space: how best to drain it?

[Highbeam]

"he suggested we throw a sump pump in a hole and pump the water out onto the lawn and see how that goes."

Good advice. Muck out a hole in the deepest ponded area. No need to trench at this point. Long term, trenching is a great idea. Go to home depot, it is not a big deal. Be sure you have a bucket to sacrifice with holes.

 

[RFB]

The inspector's opinion is meaningless unless he is willing to indemnify you against loss.

There is no such thing as "as is" when structural integrity is an issue. If you bought a used car "as is" with serious safety issues but unknown to you, it would not preclude redress of the issue. The issue here is not the equivalent of a squeaky floor or leaking faucet. This is an issue that could cause substantial loss (to you). Black mold has become such an expensive issue that many major insurers either will not indemnify for it, or severely limit the coverage. The issue with your house, unmitigated, could lead to a catastrophic loss.

You need to thoroughly document the issue (including photography), start mitigation (pump out the water), and consult with an attorney and an engineer ASAP. Further delay places more of the bill in your pocket.

As far as the mitigation step, your local fire service may be able to assist in dewatering your residence. It is also good documentation of the emergent nature of the issue.

 

[ByronBob]

I know I mentioned this before but really starting with a sump pump and drain is the easiest, cheapest idea and you would know if it was a solution you were comfortable with.

Where do the rain gutters drain to. In the pictures they seem to go underground. Is this correct and if so where do they drain?

 

[Investorguy]

@RFB - Well, we knew there was water down there, we just didn't know the extent of the problem. The inspector seemed to think it was a pretty easy fix.

Should I take more pictures than what I have?

The sump pum solution is more complicated. There are two rows of cement that run along the middle of the house (said "cripple" wall). I would need to either trench or use at least 3 sump pumps. Now all of a sudden that fix is getting more costly.

 

[Investorguy]

@ByronBob

I think that the gutters may very well be hooked into the footing drains. I don't know where they would go if that wasn't the case. I think the best solution may be to make the ditch beside our driveway into a real ditch and run stuff into there. The footings may be lower than that, but the downspouts should be there.

But honestly, 2 weeks of no rain during the wet season and the water in the crawl doesn't change even a little bit, so I think that's unlikely to be a solution.

 

[Highbeam]

So to be clear, you only have one drain draining into the ditch that runs all the time. Just one? It is not unheard of for some laborer to plumb them together without realizing the potential problems.

Don't be too scared, most of the houses in the city where I work have water in their crawls. We are in a valley between Mt. Rainier and the Puget sound. On occasion we get people calling in the fire department when there sump pump fails. Lots of 100 year old wet basements and crawls around here and these houses don't collapse or become uninhabitable. It's not a good thing but it isn't an emergency.

These sump pumps aren't very expensive. You can put three in or you can dig little trenches between the three areas. What should happen is that lowering the water level in one area of the crawlspace, the center is best, should cause the others to come down as well in a couple days. This is why digging a hole for the pump is so important, you are trying to lower the water table under the whole house and that can be done by sucking water out of a single sump.

 

[ByronBob]

Is there any pitch to the concrete. Some place where if you did put a sump pump it would drain to it?

 

[Paddy]

You need to reread the post. I did not say he needs to convert his cralw to a bacement. I said he could have a bacement IF he had a well drain site. Not fill it in as you sugest

I see you also did not even consider what filling would take. get real Three tri-axel loads on your hands and knees!

He has stated he is sitting 5' above grade that is 225' away, hardly a tidle marsh.

Purdue Engineering, class 1996

 

[inveresk]

Get real?

I could have said your boat analogy was hogwash. The hole covers the whole bottom of the boat. How on earth do you propose to plug that? I chose not to use such language because I like to keep my postings civil.

If you can't, you shouldn't be posting. This isn't a competition.

 

[RFB]

<font color="blue"> "we just didn't know the extent of the problem." </font>

Then it was not properly disclosed.

<font color="blue"> "The inspector seemed to think it was a pretty easy fix." </font>

Because he was not going to be saddled with the "fix".

<font color="blue">"Should I take more pictures than what I have?" </font>

Yes, you cannot have too much documentation. If you have not/are not promptly acting towards dewatering, you are weighting the situation against your interests. Remedy the immediate issue by pumps/dewatering by F.D. Then/concurrently, seek counsel from an attorney and an engineer.

Regardless of how "normal" or "not a big deal" anyone may consider this to be, their crystal ball does not work any better than anyone else's. If this goes sideways, you could be facing tens of thousands of dollars of repair.

 

[Investorguy]

Okay. I chatted about all this w/ my father in law.

He said the cement idea sounds the best to him. He is 100% convinced that it's the water table.

He said if you pour cement UP TO the water table, then the weight of the cement will displace the water without danger fo floating or breaking up. Obviously my little pad of cement isn't going to raise the entire area's water table. even if the water were to rise up though the cold cracks where the new cement meets the old cement, as long as the top of the cement was above the current water table, we should be okay.

This would be somewhere between 6-8 inches of seven sack concrete. Good thing there is that it could be pumped in via a vent and w/ a hose we could put it exactly where we need it. Wouldn't likely take more than a day.

Obviously we'd have to wait until it dried. He says that we could then throw the concrete right on over the vapor barrier.

I have to admit that I gravitate toward these more simple solutions. It would probably be ideal cost wise to spread a couple inches of crushed rock down there as well below the concrete.

So, given that analysis of the water table situation, does that sound reasonable?

How many yards is 6-8 inches by about 1600 sq feet?

I'd run this by an engineer before I did it, of course.

This would also solve the problem of having to rebuild the cripple wall. And posibly create a nice little (or rather large, I guess) storage area. If I go to sell I could advirtise an "unfinished basement". Well, maybe not. /forums/images/graemlins/smile.gif

 

[Investorguy]

</font><font color="blue" class="small">( Is there any pitch to the concrete. Some place where if you did put a sump pump it would drain to it? )</font>

No, it's all pretty flat down there. There's two large lakes and one long skinny one between the two cripple walls.

 

[inveresk]

6" of concrete over 1600 feet is 29.6 cubic yards. 8" is 39.5 cube. Concrete pumping would certainly reduce labour and get the stuff to where you want it and a vibrating poker would help you move it around some.

I think your solution will work as long as you finish the concrete above the highest level of the water in the basement.

Having my point of view ridiculed makes me mad but it also makes me stubborn. So I undertook a little desk exercise using your photographs. I imported one of the house and road into a CAD programme and adjusted the size so it was to scale. I then marked the approximate positions of the existing floor zone assuming a depth of 12", your crawl space, assuming a depth of 4' (base of crawl space is the red line) and an assumed position for the curtain drain on the basis that the top of it would have to be lower than the solum level if it were to reduce the water table to below it. Here I've assumed 18" lower.

I've projected the line of the curtain drain to the road and the yellow line gives a guide of where the road surface is, contiguous with the outside wall of the house on this side which is where the curtain drain would be. I've assumed that the leg of the circuit drain conducting water away from the building falls a modest 1o, the rest of the curtain drain around the foundation being level.

Given these assumptions, and the relative inaccuracies of the method I've used here, I calculate that the curtain drain would discharge at a point slightly more than 4' below the level of the road. Maybe I'm missing something but if this were the case, or even if I were out 12" or more, I can't see how it would work. This would surely be below the level of the bottom of the road ditch which must have standing water in it during at least part of the year and so, in turn, be below the water table.

Unless there's another ditch or channel you can discharge into elsewhere, the solution you propose - or a sump pump - are surely the only options?

I invite my logic to be shot down in flames but please let's keep it mannerly.

 

[CurlyDave]

1. You need a different Engineer.

2. I think this is a potentially very expensive problem. RFB has it right, you need to take easy, inexpensive steps to mitigate the problem and then force the builder to fix it.

Possibly we have the order reversed here -- go see a good Real Estate Attorney, and let him recommend an engineer. Someone who has dealt with construction defects previously will know the right engineers. Any attorney should give you a free hour.

As it has been noted an "as is" purchase does not absolve the builder from liability for hidden defects. This could very well be a hidden defect which only manifests itself in wet years. If you had the building inspected in a dry time and the inspector said "no big deal", all that means is that either he made a mistake, or it is only a big deal in wet years.

The bottom line is that there is a very good possibility that that he really does not "own" this problem, but that it belongs to the contractor. If I were the owner, I would be speaking with an engineer AND an attorney.

Another reason to talk to an attorney is the inspector InvestorGuy says looked at it, saw the water and said "it is no big deal". It seems to me that if the inspector was paid and if it turns out that what he said was "no big deal" is a big deal, then the inspector has liability for this. Maybe he has errors and omissions insurance, most professionals do. Anyway, another set of pockets to look into. And no issue of a warranty expiring.

I would advise against pumping concrete into the crawl space. A 7-sack mix is going to be lot stronger than the usual 4-sack mix and until you are 200% certain this is what is going to fix it, you should consider this as an irreversible step. Getting that out is going to be a long, backbreaking job if it is not the right way to go. Suppose an engineer ultimately says: "sump pump", but the place to put one is covered in 7-sack concrete...

Also, just because concrete can be pumped, it is not a self-leveling fluid when it comes out of the hose. It has a density just about twice that of water and a consistency like an underripe banana (without the peel).

You need to move the hose to distribute it, shovel it to repair the issues from not moving the hose perfectly, settle it with a vibrator, and level it with a scree board -- minimum. It would be better to float it afterwards.

I have pumped concrete, many times, and with 5 or six guys and good access to the job, 1600 sq ft would work out OK. With this kind of access it is going to be a nightmare.

 

[inveresk]

Investorguy, can you sling a tape in the crawl space and confirm the clear height?

 

[Investorguy]

@inverseek

Surely your construction kung fu is greater than mine. However, and do correct me if I'm misinterpreting, but you'r saying that is it unlikely that, due to the depths shown in the picture, draining the crawl via methods mentioned in previous posts would work due to the fact that my crawl extends too low?

I might be able to help w/ a few things. First, the footing drain (likely the downspouts too) empties into a ditch 225 feet away from the property. That would be approximately another 200 feet in back of the perspective of that picture. It empties into a ditch that does not ALWAYS have standing water. It only has standing water when it rains. However, my drain, 3-4 in corrugated pipe sticks out about a foot below the ground, emptying into that ditch. It is always running. Even when it hasn't rained for a week (which isn't often up here). That pipe stops flowing in May, which, I'm assuming, is when the water table receeds.

So, about how much per yard is 7 sack concrete?

 

[Investorguy]

</font><font color="blue" class="small">( Investorguy, can you sling a tape in the crawl space and confirm the clear height? )</font>

I'll try to get some more accurate measurements, including square feet, tomorrow. But it may not be until Sunday as I think my wife has my time pretty well committed tomorrow.

 

[Investorguy]

@CurlyDave

I have an injury lawyer who is a good client. I'll see if he can point me in the right direction as to whom a good RE lawyer may be.

I fear that I may be stuck w/ the problem though. We had it inspected, the inspector noted the water. We asked, as part of our offer, for a few grand to fix the problem. They said no, as they had 2 offers waiting in the wing, both of which were for more than ours. Given that this was the ONLY rural acreage available in our price range at the time, we felt compelled to worry about it later.

Later is now. Given the above circumstances, if i were a judge, I would probably say that I should have walked away from the house. But my father in law said that it wouldn't be too bad and it was fixable via the "fill in and raise the cripple wall" method.

As far as the concrete is concerned, I would hire that out if that ultimately becomes the solution. Not worth messing that up.

But I will talk to a lawyer next week.




I appreciate everyones paitence and willingness to offer advice, even conflicting advice.

We got my tractor out. I'm confident this problem can be fixed too.

 

[Egon]

Been following the thread for the last several days.

Overall situation indicates you are basically sitting on a flat area with a very high water table and a crawl space that is finished below the water table.

Yes you could use several different types of perifial pumping methods to keep the house area dry. These would require continual operation and really do not appeal to me. They are usually a sort term construction type solution.

Filling in the crawl space and capping with concrete is another method. Highly labour intensive and still leaves room for failure but seemingly the best option offered. Also requires redesign of the center wall.

Another option:
Get proper soil analyasis and then design from there using people with qualifications.

Another option may be to raise the house [ not as dificult as it may seem] Pour new walls that are much higher than the present. Backfill inside and outside the walls to well above the water table. Insulate the concrete walls and have dehumidifiers with some heat in the crawl space.

Another is to raise house, install pillings, build up an aggregate pad well above water level, poor concrete grade beams and full concrete slab to set the house on.

Then again maybe a "For Sale" sign may be the best way out.

Whatever the method used find people certified in your area for design and alteration methods.

Egon

 

[inveresk]

Investorguy, the only way to be sure about levels is to do a level survey which will tell you the relationship of the solum to your discharge ditch. Bear in mind that the further away the discharge point is from the house, the deeper the drain is going to be at the outfall because it will need to have some sort of modest fall. At 225 feet, a 1 : 60 fall will mean a slope of 3.75 feet. If the circuit drain starts off, say, 1 feet below your solum and has to drop a further 3 feet plus, where is the discharge ditch in relation to this level? If your land is pretty flat, this may be well below the sole of the ditch.

Curlydave is right about the mix. You just need a lean mix here, not high strength. You could also order a wetter slump than normal which will help it self level some and you could ask for a retarder to be included so you have more time to work it. Last thing you want here is to have a load of concrete go off on you in the crawl space before you've levelled it. I think to do this job in a day is pushing it.

Point of information - my crawl space has a concrete slab and about 3'6" clearance. If I remove the slab and dig down a bit, I'd end up with your situation. Slabs in the crawl space are mandatory here because of earthquate risk. They're mandatory in the UK where they're normally finished with a couple coats of cold bituminous solution to help waterproof them. There's no risk of the slab having to come out if you were to add it. However, the one thing you don't want to do is to pour a slab then find the top is still below the water table and you haven't solved the problem so you need to be sure just how much concrete to add. This is not a job you want to do twice.