Alfa Foundation Repair trained estimators use data collected during a foundation evaluation to spot slab leaks and review if a slab leak repair is needed.  Alfa also has its own full service plumbing affiliate.  This is important for two reasons.  First, we can help identify and locate leaks which may mean that foundation repairs are not needed.  Second, it means that once foundation repairs are completed, we can rapidly respond to any plumbing issues caused by foundation repairs.

Under slab leaks generally come in two forms, sewer leaks and leaks in water lines.  If your water lines are leaking, you usually find out as soon as you get you get your water bill.  Even a pin hole in a water line can leak out over 10,000 gallons in one month.  In contrast, sewers can leak for years without anybody knowing.  Unless a sewer is in expansive soils and a leak is adding enough water to swell the soils, there may be no signs of the leak. When a water line or a sewer line leaks enough water into expansive soils, the soils can actually swell up and lift a building.  This is called heaving.  Often when a leak is causing heaving, the presence of the leak may be suggested by the way the overlying slab is being bent.  Domes in slabs often indicate the presence of leaks.

HOW DOES ADVANCED TEST FOR A LEAK

For water lines, there is a simple two step test.  First a pressure gauge is attached to a spigot and the spigot is opened.  As long as all water use is stopped, the gauge will show the pressure at which water is delivered from the street.  Next, the water meter is turned off.  If there are no leaks, the pressure on the gauge will remain constant.  If the pressure falls, it means that water is escaping from the lines in and under the house. 

Generally, if a pressure drop is found, taps, toilets, and other water outlets are rechecked for drips or slow use.  If no drips or slow use, such a running toilet, is found, then the lines must be leaking under the house. For sewers, there is also  simple two step test.  First, the sewer line is blocked off with a balloon where it comes out from under the foundation.  Next the sewer is filled with water.  Given that the sewer is blocked off from the main, if the water level in the sewer drops, there must be a leak.