Tree Roots and Shrubs
The effects of tree roots and shrubs on concrete slab foundations.
I was looking at a map from the US National Weather Service that showed almost a third of the country in drought conditions that range from “excessively dry” to “exceptional drought.” Not good.
And to make matters worse, many areas included in the drought also have homes built on shrink/swell heavy clay soils. That means when the soils dry out, house foundations start moving, usually dropping.
Things the homeowner will start to notice are cracks in the sheet rock inside and in brick veneers outside. Doors and windows that don’t work the way they used to and are supposed to, and in the worst cases, floors starting to slope.
It’s happening again at my house too.
Extended dry conditions like this provide plenty of work for foundation repair companies, but what about the homeowner?
Here are 5 Foundation Repair Issues To Be Aware Of
I’ve been doing quite a bit of cosmetic fix-up inside the house over the last 10 months or so since I had root barriers installed. At the same time I had large shrubs removed from the west side of the slab foundation.
In the meantime I’ve been fixing drywall and painting. There were some small wall cracks that needed filling and some areas where sheet rock tape had popped, things to be expected of a thirty year old house that has a concrete slab foundation sitting on shrink-swell heavy clay soil. So far things have stayed fixed.
The was one crack in the ceiling near the patio door that was always kind of an indicator of foundation movement for me. It would open and close ever so slightly depending how much rain we had gotten or how faithful I had been with running the soaker hoses.
Well sir, that crack has stayed closed for several months now. I don’t know if it’s because of all the rain we’ve had this year, the root barriers, the soaker hoses or a combination of all three. It’s probably the latter. At any rate, it’s nice to give the drywall mud knife a rest.
This little blog is written from the Dallas, Texas part of the globe which happens to be in one of the busiest areas for foundation repair companies. Why?
Most of the residential neighborhoods are built on what used to be black prairie farmland. Where once they grew cotton they now grow housing developments planted in the same heavy clay soils.
These soils swell when wet and shrink when it’s dry. The result is rising, falling and twisting of the average slab-on-ground concrete foundation. The use of soaker hoses to keep the soil around the foundation moist is a must. (more…)
Another thing Tom the Contractor suggested for reversing the loss of moisture under my slab foundation after the root barriers were installed was to rehydrate the soil. That’s a fancy word for squirting water into the dirt under the house.
One of his crew went all around the foundation with machine similar to a power washer with a plunger attachment. A garden hose was attached and the plunger was pushed a good three feet deep into the soil every 24 inches or so. A valve on the handle controlled the flow of water.
Between the rehydration treatment and a better soaker hose configuration we are getting moisture back into that clay soil.
UPDATE: This was probably not needed given the slab leak that was discovered a few years later.
The structural engineer who inspected my concrete slab foundation recommended tree root barriers be installed to stop foundation settlement due to loss of moisture in the clay soil that my home sits on. The thinking is that trees can suck a lot of water from under a foundation and contribute to the shrinking of clay soils which in turn causes differential movement of the slab. You see the results with cracks in sheet rock, separation of trim, doors and windows that stick or uneven floors. You know, bad stuff in the house.
Yesterday the contractor and his merry band of shovelers and ax wielders arrived, took out shrubs and put in root barriers. Please indulge me and read about it here. Thanks.