Basement Perimeter Drain


  #1  
Old 06-18-03, 07:01 AM
bunti72
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Basement Perimeter Drain

Hi, Iam a newbie here. I just bought a 3 year old house in North NJ. I have noticed lots of effervesence on the cinder blocks about 7 ft. high from basement floor (unfinished basement). I have also noticed couple of horizontal, veritical & step cracks on the blocks. Sometimes the lowermost block looks wet but till now no actual water seepage or anything. There is no soil grading around the house & I can't do it on my own. The quote I got for soil grading is $600

Just to be on safer side, I called couple of basement professionals & they gave me quotes ranging from 5000$ to $15000 for 150 linear feet of complete perimeter drain inside basement, sumppump & lifetime transferrable warranty. All these companies have similar products & the company that gave 5000$ quote wants to beat his competors & that was why he lowered from 7000$ to 5000$

SO, my questions now is,
(1) Has anyone already done such perimeter drain
(2) Is it worth it
(3) Is the quote that I have got now a good deal
(4) Do I still need soil grading
(5) Any other points that I need to look out for.

Thanks in advance for your responses.
bunti
 
  #2  
Old 06-18-03, 10:02 AM
Doug Aleshire's Avatar
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bunti72,

What you are considering is an large investment but one I recommend. See the jobs they have done, talk to customers and then choose wisely. Along with this installation,all other areas are just as important, landscaping, gutters/downspouts, caulking.

The best way of keeping liquid water away from a foundation is to divert downspouts away from the house, and slope the ground away from the house. In that way any rain, snow melt, etc. will not drain down into the soil near the foundation. For any water that does drain down into the soil near the foundation, and also for any excessive ground water already in the soil from a high water table, a perimeter drain tile and stone or gravel backfill has been the standard approach. This is a waterproofing system. The same application is done to the "interior" of the lower level and this works extremely well especially in older homers when exterior applications cannot be done.
When liquid water gets into such a gravel backfill, it quickly runs down into the drain tile and is diverted away through a pipe either by gravity or a sump pump. When a drain tile is used, but soil is used for backfill, the water can't drain away as quickly, so it tries to drain through the foundation wall. If enough liquid water is present, hydrostatic pressure will force it through any opening it can find in the foundation wall, no matter how small.
The purpose of the stone or gravel backfill is to relieve the hydrostatic pressure. With the correct backfill material, the liquid water will travel the path of least resistance: through the backfill into the drain tile, rather than through the foundation wall. I will point out that drain tile comes in two styles - rigid and flexible. The rigid has a slot on one side and this is installed with slot down. The flexible has slots on 4 or 6 sides, if you will but this should be installed with a silt sock over it. Costs more but prevents silt from getting into the pipe. Most homes, for interior applications use the flexible but either is acceptable.
When the soil is merely damp, as it often is, liquid water isn't the problem. When damp soil is next to a foundation, it will cause the foundation to get damp. The dampness will work its way through the foundation wall and eventually enter the basement or crawl space. Concrete and masonry are actually very porous, so dampness can move through such materials fairly easily. (This is done through a process called capillary action.) Once the dampness reaches the interior surface, it can evaporate into the basement or crawl space, increasing the moisture in the air.
To stop the dampness is relatively easy because, by not being in liquid form, there is no hydrostatic pressure. A simple foundation coating will do the job. This coating is called dampproofing. It isn't a substitute for waterproofing.

PROCESS: Remove about 16" space out from wall. Ensure that you are about 8 inches out from footing. Dig a trench along the footing that slopes gradually towards a sump basin. Trench approaches the sump basin from two sides. Drill ¾" holes into each of the block cavities (2 per block) in the course of blocks that sits directly on top of the footing. Water now comes out of these holes when it rains. Place 4" corrugated drain pipe in the trench and run this all along the trench to the sump basket. You may use a silt cover or a silt sock which covers this pipe of which then you would place 3/4" pea gravel over this to a level that leaves about 4" of space for your new concrete. Place the concrete all the way to wall - NO SPACE IS REQUIRED. Install a good sump pump and PVC piping - 1 1/2" out to the exterior and away from the homw for proper drainage. This could be buried and run into a drywell at least 20 plus feet away from the home on down grade.

http://www.dspinspections.com/basementwater.htm

http://www.binkleyandober.com/residential.php3

http://www.usinspect.com/Crawlspace/PerforatedPipe.asp


Just a note on sump pumps and backup systems...

I would not even consider a "Battery Back Up Sump Pump". Reason you may be asking is that it is not a guarantee that they will work when needed. As with most homeowners, we don't always check on things when we are supposed to. If it is out of sight, it definitely is out of mind!

I would recommend a good water powered sump pump backup like the Guardian, normally available through a plumber since they don't sell these over the counter through a plumbing distributor. They are not cheap, runs about $450 - $500 but this must be plumbed into a 3/4" line, and installed before going to any fixtures or tees. Labor on these can be $350 plus. The water pressure from the city powers this and does quite well - for every gallon of water used, 2 gallons is pumped out. It requires a 1 1/2 PVC pipe for discharge.It does come with a Backflow Preventer for the water inlet pipe but you will need to get a check valve for the 1 1/2" PVC line. It can lift the water up to 15 feet at 407 GPH. At 10' it is 580 GPH. It does have an adjustable float that is placed adjusted just above your existing sump pump. So when the power does come back on, your's would kick on and the back up automatically shuts down. Simple and very effective.

I am an advocate of this and have installed many, especially after a client calls and says their battery back up failed. What usually happens is the batteries fail or if wired in on its own circuit, the power goes out, breaker trips and it doesn't recharge. Other cases, the batteries have just failed. If you don't check on it, you will have problems. At least the water pressure is more of a guarantee than the battery backups. I stress this is just used as an Emergency Back Up.

Some links to look at...

http://drylock.com/H2Dry.html

http://www.ugl.com/faq.html

http://www.hhinst.com/Artfoundations.html

http://www.moncton.org/search/englis...e/flooding.pdf

http://www.dspinspections.com/basementwater.htm

http://www.oldhouseweb.net/stories/Detailed/10199.shtml

Hope this helps!
 
  #3  
Old 06-18-03, 10:51 AM
bunti72
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Thanks for your informative response, Doug.

bunti72
 
  #4  
Old 06-18-03, 10:56 AM
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bunti72,

I know it was lengthy but I'm glad it helps!

Good Luck!
 
 

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