In a recent inspection of a house in the historic district of McKinney, TX I had to call out the pier and beam foundation due to a leaking sewer under the foundation. This is not an uncommon outcome with properties built between 1950 and 1985 where they have cast iron sewers. Due to privacy issues I can not publish the inspection report here but I can share some of the information that was in the report.
Foundation Opinion: There were general indications of foundation movement present and visible, such as sheet-rock cracks, brick cracks, and sticking doors frames. Based on these observations made at the time of the inspection the foundation in the inspector's opinion appeared not to be performing its function. In addition there is a heave in the foundation that may be caused by water penetration under the foundation.
Table 1 provides the average levels of foundations measured by Yellow Hat Inspections. Each column provides the average level for vectors P1 to P4. Each vector is an average based on eight measurements of individual foundations from a population of 60 foundations.
P1 P2 P3 P4
Average 0.21712 0.233152 0.334511 0.366033
The variation in the readings recorded for this foundation vary significantly from the average foundation.
Remember when you look at these types of measurements they are a snap shot in time. The levels will change over time and most times these changes will be small. You should pay attention to your house structure and look for changes in the walls, doors, windows and floors. If you find changes occurring such as sheet rock cracks or cracks running from a window corner to the foundation or roof consider having the foundation measured again. Only by measuring can you identify certain types of conditions that threaten your structure, just looking is not good enough!
The table below provides the measurements taken of the foundation level on the day of the inspection. P is the position for each set of readings R. The readings run from the rear elevation to the front.
Foundation Opinion: There were general indications of foundation movement present and visible, such as sheet-rock cracks, brick cracks, and sticking doors frames. Based on these observations made at the time of the inspection the foundation in the inspector's opinion appeared not to be performing its function. In addition there is a heave in the foundation that may be caused by water penetration under the foundation.
Table 1 provides the average levels of foundations measured by Yellow Hat Inspections. Each column provides the average level for vectors P1 to P4. Each vector is an average based on eight measurements of individual foundations from a population of 60 foundations.
P1 P2 P3 P4
Average 0.21712 0.233152 0.334511 0.366033
The variation in the readings recorded for this foundation vary significantly from the average foundation.
Remember when you look at these types of measurements they are a snap shot in time. The levels will change over time and most times these changes will be small. You should pay attention to your house structure and look for changes in the walls, doors, windows and floors. If you find changes occurring such as sheet rock cracks or cracks running from a window corner to the foundation or roof consider having the foundation measured again. Only by measuring can you identify certain types of conditions that threaten your structure, just looking is not good enough!
The table below provides the measurements taken of the foundation level on the day of the inspection. P is the position for each set of readings R. The readings run from the rear elevation to the front.
The chart shows the ZIP levels results. The foundation was found to have a 3" variation within 20 feet. In addition there were binding, out-of-square, and non-latching doors, as well as frieze
board separations and sloping floors that can indicate foundation
issues.
The cause of all this movement was the sewer line and the following stills taken from the sewer cam video show the extent of the problem. In this picture you can see that the cast iron pipe has separated from the PVC pipe allowing the effluent to run out of the system under the house.
If these problems were not enough, there were more problems with the sewer line running down to the city tap. The following two pictures show the pipe is broken at two points.
These findings show how important it is to have the sewer lines video-scoped as a leaking sewer can lead to extensive structural problems. Water intrusion under a foundation is one of the most destructive conditions that can be present. According to Robert W. Brown, Foundation Repair Manual, p9.4, p 9.7, McGraw-Hill 1999 "In areas where expansive soils are present the amount of water needed to cause a foundation to heave is very small, less than 0.5 oz. per day, every day over years." Furthermore Brown states that water accumulation under slab foundations accounts for 70% of slab repairs and sewer leaks are a high proportion of these failures.
The sewer problem was very evident via the sewer cam video but without it there would be no way of telling the true extent of the issues with this house. It looked picture perfect to the untrained eye and anyone buying it would have to sink around $30,000 to fix the problem!
