A big question is what kind of soil you have under and around the
foundations!

A firm I once worked with did a big sprawling campus style high school and
simply went with the details supplied by the geotech and engineering
consultants.   They provided "standard practice" details.   By the time the
building was three years old, there were cracks in the concrete block walls
all over the building large enough to put you fist in (4").    Major law
suits.

The problem was finally traced to the foundation drain tile system and the
fact that there was one at all.   It turned out that the site had a giant
layer of expansive clay about 4' down, just below the 3'-6" deep footing
level.   When drain tiles were placed around the building, they collected
water and moved it right to the expansive clay layer.   The final decision
was that there should have been no tiles at the foundations, and that the
grade level soil should have been bermed to slope away from the building and
topped with a layer of the expansive clay commonly used to line farm ponds,
preventing water from penetrating the ground near the building.    The tiles
were dug up and removed, and after the berming and clay topping was done,
the building ceased to move.

Salt and Cement Parging Mix:
My parents home in Ithace, also built on clay, had a problem like yours but 
not as bad as the school.  A concrete specialist out here in BC absolutely 
hated tar on concrete walls, and recommended a mix of salt and cement for 
filling cracks and parging the outside of the foundations if possible or 
just the insides if that was all that could be afforded.   We did it and it 
worked like a charm.   He explained that the salt was water soluble and 
would follow the water back toward its source, but when it dried, crystals 
would  form within the concrete and water would no longer penetrate the 
micro cracks.   When any new water appeared, the outermost crystals would 
dissolve into it and move back through it making a saline solution, but not 
enough would dissolve to allow the water to continue to move forward. 
Although commercial products were available to do the same thing, that 
simple homemade mix (cheap) sure worked on the earth sheltered buildings I 
did in that era, and the engineer swore by the stuff.


cp in sometimes soggy bc



----- Original Message ----- 
From: "Lawrence Kestenbaum" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, June 26, 2009 7:36 PM
Subject: [BP] Basement issues


>
> My house is a 38 x 22 foot ranch house built in 1953; we have owned it
> for ten years.
>
> We are on high ground by Ann Arbor standards.  However, there is water
> on the basement floor after a heavy rain.
>
> The basement is built of concrete blocks.  There are cracks, growing
> gradually in severity over the years, on all four basement walls.  The
> cracks are vertical at the corners, horizontal along the walls.  At
> one end of the house, the wall is bowing inward noticeably.
>
> One noted local contractor told us we needed to hoist up the house,
> tear out the basement, rebuild it from scratch, and attach the house
> to the new basement.  He offered to do this for $50,000.
>
> Of course that doesn't include the cost of moving or replacing our
> relatively new furnace, hot water heater, and circuit breaker box,
> disconnecting and reconnecting the plumbing, re-landscaping the yard,
> etc.
>
> Friends of ours who had to do this with a much larger and older
> 2.5-story house spent a total of some $100,000.
>
> A second contractor recommended a different strategy.  He would tear
> out a couple feet of the basement floor on all four sides, install new
> footing drains, and replace that part of the floor.  He would also
> install 21 vertical 4-inch I-beams along the basement walls to
> preclude further movement.  He offered to do all this for $16,100, and
> guarantee a dry basement for a lifetime, transferable to future
> owners.
>
> What do Pinheads think?
>
>                                                          Larry
>
> ---
> Lawrence Kestenbaum, [log in to unmask]
> Washtenaw County Clerk & Register of Deeds, http://ewashtenaw.org
> The Political Graveyard, http://politicalgraveyard.com
> P.O. Box 2563, Ann Arbor, MI 48106
>
> --
> To terminate puerile preservation prattling among pals and the
> uncoffee-ed, or to change your settings, go to:
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--
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