Plateau Inc.

A Case Study:

Recently we conducted an evaluation of moisture problems for a client. The problem periodically manifested as ponding water in the cellar of the home. He was certain that the problem was associated with a seasonal water table.  

Investigation of the area revealed the subtle signs of soil piping. Near the ponded water were small holes and crevices that are indications of water movement through the soil. These indications suggested a specific water source, that was not associated with the water table.

Careful inspection near the home found a small sinkhole near the front of the home below a downspout. As a test, water was discharged to the area. Sure enough, about 10 minutes later water appeared in the cellar... over 50 feet away!! This classic manifestation of soil piping probably took several decades to evolve, but the results were undeniable.

Soil piping can take a long time to evolve, usually 4-10 years or more. Fully evolved piping can create underground channels, small and large caverns, and ultimately, extreme foundation  failure.



Drainage and Moisture Control


Plateau can hep resolve site and building drainage issues.  In Colorado, the last thing you want near your building is excessive moisture. Corrective actions for water issues almost never rely solely upon the installation of sump pumps. Let me rephrase; Relying upon a sump pump as a means of water control can cause more damage than doing nothing at all! And yes I will tell you why (read the case study to the left for one example). 

Soils in the Rocky Mountain region are notorious for qualities that cause extreme foundation damage. Expansive and corrosive soils are common, especially in the low lying locations throughout the area.  The results of excessive moisture near your foundation are cracked foundations, spalled concrete and in extreme cases moldy crawlspaces. If water has entered near your foundation, installation of sump pump within the building may not help but may cause more damage. The key is to keep active water away from the the building.

Sump pump installation is sometimes accomplished as part of the investigative phase. This is especially useful for basement and crawlspace homes where the below grade portion of the home essentially becomes a monitoring well. Before we can determine a source of water, we must remove the standing water so that careful monitoring of the foundation area can proceed. Potential sources of moisture are numerous and can included potable water lines, sewer lines, previous excavations, surface runoff, springs, elevated water tables or a combination of any of the above. 

The next key to addressing soil moisture issues is the need for moisture vapor control. All soils will emit some water vapor, even ones that appear dry and firm to the touch. Over a large area this can add up to a significant amount moisture that can affect your entire building envelope, causing structural issues and mold. There are many options for vapor barrier installation from loose laid 6 mil. polyetheylene to heavier sealed systems. What is right for one home is not right for the other. In most cases a simple loose laid system is all you need. A fully encapsulated system looks great and can be useful in some situations, in others it can cause damage to your foundation. 

When corrosive soils are present, the choice and application of vapor barriers is affected. Fully encapsulated systems can cause an adverse moisture drive through the foundation, creating spalling on portions of the concrete exposed to air. The damage is usually not a structural problem, but try telling that to a prospective home buyer. Ideally, corrosive soils should be addressed during the design and construction phases. If that has not happened, then remedial plans should be carefully considered. Concrete damage will continue perpetually unless proper means are implemented to stop or control its effects.