#6-Foundation Settlement

Popup #6

Foundation Settlement

Shifting or sinking foundation causing wall/ brick cracking, uneven floors, and structural damage.

Foundation Damage Prevention

Foundation damage is more than just cracks and settling. Water accumulating around the foundation can lead to problems like mold and pest issues that can quickly make a home unhealthy. You can literally double the healthy life of your home and foundation with a proper drainage system. This is just as important as a good roof in terms of keeping your home healthy.

Cracks and settling are typically caused by undermining and/ or unstable base soil. They can also be caused by issues during construction like poor quality concrete or by concrete being poured on frozen or unstable base soil. Either way, the best way to prevent or arrest cracking and settling issues is to ensure good drainage and waterproofing systems are in place and well maintained.

Foundation Issues Can Affect Air Quality: The home's ductwork typically runs through the basement or crawl space. Ductwork is not airtight. It can leak up to 6%, even when it's brand new. This leakage allows it to draw in damp, moldy air from the crawl space or basement and can contaminate the air in the living space.

1. A moldy air vent caused by the HVAC system pulling in moldy air from the crawl space.
2. Mold growth on floor joists lead to wood rot.

Solutions:

• A good downspout drainage system to carry the roof water away is the #1 Foundation health priority. Each downspout discharges an average of over 200 gallons per one inch of rain. If this water is not properly routed away from the foundation, it can overburden the foundation drain system and basement waterproofing, causing undermining, wetness in and around the foundation, pest issues (since pests are attracted to wetness) and mold. Downspout systems when properly designed and installed should also include routing the PVC pipe through low areas in the yard and adding surface drains where necessary to prevent standing/ pooling water.
• Ensuring that the foundation drain is in good working order is also extremely important. In our experience, most foundation drain pipes on homes over 2 years old are often somewhere between halfway clogged and 98% clogged. Homeowners generally don't know about these drains or where they outlet to or how to maintain them. If the foundation drain is clogged, water can build up in the system around the base of the foundation causing the base soil to soften and other wetness problems. Foundations on soft soil/ mud are more susceptible to cracking plus this wetness increases moisture levels in the crawl space or basement which causes mold and attracts pests.
• Proper waterproofing should have been installed when the home was built. This is the tar or membrane that is applied to the foundation walls to prevent the porous masonry or concrete from wicking in water. Unfortunately, these coatings or membranes are often applied to the foundation walls when they are wet, icy and/or dirty. Waterproofing has actually been renamed damp proofing in most building code books because it does not really make a basement waterproof. Waterproofing should come at least up to the grade line on the exterior of the home. We often see soil built up on a foundation wall much higher than the waterproofing. This also allows water to wick in.
• Grading should slope away from the home a minimum of 6 inches in 10 ft according to most building code books. In areas where this is not possible, for example, when there is a home 8 ft away from yours, linear drain(s) should be installed along this portion of your home to make up for the inability to achieve proper grading to prevent water from standing between the homes.
• A sump pump should be installed if there is insufficient fall on the property to run a gravity drain. A gravity drain is typically preferable but in some areas they are not practical or feasible. Where gravity drains aren't practical, the sump crock provides a place for the footer drain / foundation drain to discharge into so that it can be pumped out away from the home by the sump pump and exterior drainage system.
• Crawl space sealing is important if your home has a crawl space. We're learning more and more about the toxicity/ neurotoxicity of mold and how it can have long-term negative effects on our health. A sealed crawl space that is heated and cooled provides geothermal energy benefits plus allows the moisture and temperature of the space to be controlled. Differences in temperature cause condensation, which is essentially wetness. As wetness increases, humidity and moisture levels increase which leads to mold, wood rot and pest issues. A sealed crawl space can be kept clean and healthy. This means that the air in the rest of the home will be cleaner and healthier. It's common to have significant amounts of ductwork as well as air handling units located in the crawl space. These units are not completely sealed, allowing up to 6% leakage even when brand new, so they let crawl space air in which is then circulated throughout the home.

There is an important step to take before sealing your crawl space. it's making sure that your drainage system is well maintained and optimized. Otherwise, water can ruin the crawl space sealing system. Basically white vinyl or plastic material is used to seal the inside of the crawl space. This material is taped together and glued to walls and piers. Too much moisture causes the glue and tape to separate from the plastic over time which causes plastic to all the way which allows the moldy air to escape into the home. Drain Designs is the drainage specialist so we do not seal crawl spaces but we partner with excellent companies that do this type of work.

In this image, the plastic has been pulled back from the crawl space floor to expose the moldy mess underneath.

Wetness can also weaken mortar over time. Here's a photo showing how condensation inside of the walls leaks down onto the joints, is pulled through by vapor pressure thereby causing the mortar to literally disintegrate.

The bottom line, a good drainage system is Job 1. Before you invest money in cleaning, conditioning and sealing the crawl space - it's important and wise to protect your investment by making sure that the drainage and foundation protection systems are optimized.

A good drainage system costs far less than the problems it prevents. One crack in the foundation or a failing sealed crawl space system can depreciate a home more than the cost of the drainage system that could have prevented it - while offering lots of other benefits. A good drainage system lasts a lifetime and does not depreciate. When properly installed and maintained it will work just as good 20 years from now as it did the day it was installed.