Updated: Jul 20
Time and again we’ve spoken about seasonal weather changes; soil being too dry, soil being too moist, but the fact of the matter is most of the time foundation issues always go back to this. We have talked about how high plasticity soil works and how it reacts when being too moist, so we are not going to go into too much detail regarding that, except to say that: rain season = soil too moist = expansion of the soil = foundation damage.
What we will go into detail however, is what to do and how to be prepared to deal with the rain season in order to avoid your soil getting too moist, therefore help preventing possible foundation damage and it all comes down to drainage methods.
And it is not only the possible foundation damage that you have to look after when dealing with rain, but the possibility of moisture, which can cause both structural problems and mold growth which can eventually pose a health hazard to you and your family.
So the main thing is to make sure that water will not collect around your home, effectively avoiding heaving, which is when the soil swells up with water and lifts the foundation, causing damage to it. And one of the best methods of preventing water damage is to make sure that the house and foundation lies on a slope. A sloped terrain will make water naturally drain away from your home; ideally the slope should be at a 5%, which translates as six inches for the first ten feet. This is referred to as a ‘positive grading’.
If, however, your house does not have a positive grading and it lies on a flat surface it is of outmost importance to have a drainage system, or even a water pump when deemed necessary.
We will start with roof drainage. Given the surface area of your roof, even with minor rainstorms it can take on a huge amount of water. Without a roof drainage the water will run off landing all around the home, which will build up and seep into the walls and foundation. The whole point of roof drainage is to have a system that will ensure that the water is drained away from your home/foundation. This will be achieved with the use of gutters and downspouts. One thing to have in mind however is the need properly maintain it, making sure the system is free of leaves and foliage, otherwise proper drainage cannot be insured.
Of course, sometimes roof drainage will not be enough so your second line of defense will always be the ground gutters. Specially since roof drainage will not address the issue of ground water, so that is when the ground gutters come into play. They are essentially trenches dug around the house with the purpose of diverting the water away from the structure/foundation. These are lined with waterproof material and pipes are laid at the bottom of the trench to direct the water away from your home, insuring the safety of your foundation.
French drains are also an alternative. These are trenches filled with gravel or rock and may or may not have a perforated pipe and are also primarily used to prevent the water from reaching the foundation. Basically it works pretty much in the same way as a ground gutter, just a little different. The thing with french drains is that they work marvelously with landscaping and besides being quite helpful they can also look quite beautiful if taken into account when designing your lawn.
Finally there are some cases when these resources might not be enough. Let’s say your house has a negative grading. Meaning that due to it’s placement water will run towards the house and foundation. That’s where the water pump comes in. Using piping to redirect the water to a safe distance (or at least until it reaches a point with a positive grading), it will pump your water away from your home, helping keeping the structure and foundation as dry as possible.
Given how vital preventing water from reaching your home foundation is, you should never leave it to chance. Specially during the rain season, so if you are in need of any inspection or any additional service to help out with this, do not hesitate! Give us a call and we will be happy to put our expertise to work, in the name of the safety of your house and your tranquility.