Groundwater
Groundwater
(OP)
I'm looking for some guidance. I live in a condo community with 56 units (small). Water leaking into basements has been an issue since it was built 17 years ago. The grading is horrible. Our Association spends thousands each year repairing leaks in basements, changing the grading outside, etc., but nothing seems to help. There are several areas between the units that appear to be small "bogs". I use that term loosely because I'm not really sure what a bog really is. We would like to hire an expert to come out and tell us what really needs to be done. Waterproofing people and landscapers really don't know. I'm guessing we need a Civil Engineer. Where does one go to find one? I live in Michigan (a suburb of Detroit). Any help/direction you can provide would be appreciated. I also might add that we live not far from a flood plane.





RE: Groundwater
you might be able to find some information on these sites
http://region3.asce.org/
http://www.ilspe.com/
RE: Groundwater
Source of the water could be ground water or surface water or both. I will try to summarize treatments. Assumed here is that downspouts are routed well away from the structure and the ground surface is sloped away.
I suspect that there may be failed perimeter drains at the building. If so, it is likely some well meaning builder (and unfortunately too many engineers and architects)call for surrounding the drain pipe with gravel. Gravel is not a filter of soil and the voids easily plug and the system fails, sometimes the first year of use.
If there is a perimeter drain system, dig down to typical places and check for the condition.
You msy or may not have to replace it. If the source of water is actually ground water, yes replace it. however, this time use a good filter around the pipe (slotted plastic). You may find some folks in this group that say surround the pipe with a filter fabric, or they ay say surround the gravel with a filter fabric. that may work, but I have seen the sock covered over with mud and seals it shut. Surrounding the whole system with fabric is very labor intensive.
A good way to do this is place the pipe and then simply dump in a good filter to cover the pipe and go maybe a foot or two above it. A good filter is ASTM C-33 FINE AGGREGATE (CONCRETE SAND). Very easy and concrete sand does a great k=job of filtering all types of soil.
On my jobs, the specs say "No gravel allowed on site" or some well meaning workman will use gravel instead of the sand.
It may be possible to correct the problem by waterproofing the ground surface.
Do this in this manner, after you remove all landscaping plastic, decorative stones,bark chips and the like.
Fill in depressions, as between sidewalk and building.
The strip sod in all areas where there is backfill to the building. It may go 15 feet out from structure.
Apply 2 pounds of powdered bentonite to this earth surface and mix in thoroughly in the top 2 to 3 inches.
Do not use granulated bentonite, since it does not work as well. Do this on a calm day, Use a garden roto-tlller for this mix and be thorough.
Work around bushes as close to them as possible. Do not try to seal stone landscaping areas in depressions and hope to seal a bathtub. This "roof" all should be sloped.
The sod can be replaced and grass will grow great. Bentonite ( a natural volcanic clay) fill soils voids when damp and is a great seal.
If you can't do the whole job, do the most likely places first.
Don't use excessive bentonite or you will have soggy lawns for all summer.
RE: Groundwater
Apply 2 pounds per square foot. That is, in every 5 x 5 foot square use one 50 pound bag.
You get this at plumber supply houses and do not use granulated. You must use powdered bentonite. Common term is Volclay or driller's mud.
This forum system accepted my text before I wanted to (above), but maybe this will help.
RE: Groundwater
I would contact a large sized landscaping firm and tell them you have a method that they must follow. If you check in the local yellow pages under civil engineers, look for one that does site development, but you still need a good landscaper and they must do it my way.
I have trained many a landscaper, since none that I ever found knew about this method.
Also, I never knew a civil engineer that has done this either.
However, it works great when done as I describe.
RE: Groundwater
RE: Groundwater
RE: Groundwater
RE: Groundwater
http:/
RE: Groundwater
RE: Groundwater
In looking to hire an engineer, first ask for their references for jobs like this solved.
Then check with those references, and see if the problem really got solved.
If you don't get a positive comment, move on to others.
The engineer category most likely to solve it is Geotechnical Engineer, a branch of Civil engineering.
RE: Groundwater
RE: Groundwater