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Alan Johnson
Basement Cracks

This Spring We had alot of rain in our area and after a month and half I noticed the wall of cement block (in my basement) had crack as much as a 1/4 inch or even 1/3 inch and it surprised me because when it rained it never leaked a drop. My question is do we have a problem or can I seal the site with calk, paint over it with waterproof paint and then paint our normal color or are we having a problem with stress and can this get worse and should I hold off for awhile and see what it does?????

The crack runs horizonal at about 6' from the floor..on the south
wall.. 5' on the west wall.. 5' on the north wall, this is a crack that run the whole length of the wall( most times just a crack) even in a t-block support column..Should I get a hold of a basement expert (leaks, support, drainage problems)

Re: Basement Cracks

Yes, I think an expert should be consulted.

If you recently bought this house, you may have a claim against the builder or seller, which you should investigate further.

There's no need to panic, or loose sleep over this, the house isn't about to fall down & these things can usually be rectified; the first step is to find out EXACTLY what's going on with the wall.

You could try the Yellow Pages under "Foundation Contractors", who specialize in this type of work, or "Home & Building Inspection Services".

There are also "Engineers, Civil", who have more extensive training in why basement walls crack, but they usually charge more for the consultation.

It could be from any one of several causes.

A lot of rain soaking into the soil puts a lot of added pressure on masonry/concrete walls; this is especially true if the wall is at the bottom of a downward slope of the property, so the water is moving down a slight hill & accumulating against the wall.

This could possibly point to clogged perforated drain pipe (french drain) at the bottom of the foundation (or a missing french drain), that allows the water to accumulate against the wall (and freeze in cold climates).

Horizontal cracks along the upper section of the foundation wall are often associated with winter frost heave, if you happen to live in a cold climate.

Sometimes the upper layer of soil is removed & discarded & replaced with a more pourous gravel/sand & the surface reseeded with grass.

The soil then has to be pitched AWAY from the house & roof gutters have to be extended 10' or more away from the foundation to prevent water from accumulating near the foundation.

If there is a lot of clay in the soil, it will expand during rainy periods placing a lot of added pressure on the masonry walls; thus, clay soil around the house is often replaced with gravel.

The sites below offer some POSSIBLE issues related to wall cracks, but they may or may not apply to your particular wall; that's why it's important to have someone look at it.

Diagrams 201, 202, & 224 are listed under "Foundation & "Structure" headings.

The larger diagrams may not load properly on some systems; if so, Google "Soil pressure on foundations" & load the "cached" version of Nemmar with your browser, this usually works.

Pages 2 & 3 of the Popular Mechanics site also list some repairs in certain cases.

Also Google "soil pressure on foundation walls" (with & without the quotes) for more sites & info.

Please post back & let us know how you make out.


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