Foundation’s Settlement Q & A:
Updated: Jul 15, 2021
Some of Frequently Asked Questions about Foundation Settlement:
Q:
Is Foundation settlement repair a DIY (Do it yourself) kind of a project? If not, Can I hire a handy man to do the work for me?
A:
I often get these kind of questions from my clients. The short and quick answers are No & No.
Foundation problems, like foundation settlement, will always require a professional’s inspection and evaluation and it is my recommendation to hire an unbiased/impartial professional to provide their evaluation and opinion (preferably not a sales person trying to sell you their company's services or products). Each situation will have its own solution, some problems could be corrected when correcting the root cause while others will require both correcting or eliminating the root cause and a repair of the problem to stabilize the foundation.
Q:
What is the main cause for foundation's settlement?
A:
1. Change in moisture content in the soil causing excessive drying or wetting. We will discuss each separately.
Drying: Soils typically shrink when it is dry, during prolonged dry periods especially if you have excessive vegetation around your foundation walls or trees that draw up hundred of gallons of water each day. As your soils dries out, it will start having voids (air gaps) that will start to collapse, once the soil supporting your foundation walls get too dry it will start settling causing your foundation essentially to settle accordingly.
Wetting: This could happen during heavy and prolonged rain storms/flooding where underground soil becomes over saturated causing the soil to become extremely soft especially with clay type soil, along with that poor drainage that will prevent water to drain away from the foundation.
Plumbing leaks (water or waste water) due to a broken pipe, roots or any other reason will cause the saturation of the soil.
2. Voids in fill due to the lack of proper compaction in the disturbed soil area under your foundation walls.
The best way to simplify it, I always tell my clients that the soil surrounding the foundation walls of their property was disturbed, and often times builders bring in loose soil to grade the ground evenly before placing the foundation. This fill soil will never have the same density that the original soil had and unless it gets compacted thoroughly before placing the foundation on top to eliminate all of the voids in it, it will always settle in the future and essentially settling the foundation on top of it.
It is important to mention that differential settlement is a little more common and it could be due to localized problem near one side of the house than others that could majorly impact the soil, like a huge tree near one corner, or a broken downspout drain pipe, or a water leak, or even a negative grading to one specific corner.
These are few of the major elements that contribute to foundation settlement, covering every condition is beyond the scope of this educational blog. If you have questions about your foundation feel free to email us: info@pittdes.com
Picture shows both signs of a bow and settlement
Written by Firas Abdelahad, P.E.
Firas Abdelahad has been practicing structural engineering over 15 years working with teams of consultants, architects, investors, homeowners, contractors and subcontractors to come up with solutions for challenges may arise during design and construction phases.