This is our dream home. Built in 2007 and finished in 2008. It is build in Fox Creek, a subdivision developed by Powell Custom Homes. The soils in Fox Creek are primarily clay with a lot of rock on some of the lots. Powell was not the general contractor however Powell was the sub-contractor for the poured walls which included the retaining walls. They also did the excavation as well as the drain field.
Clay is a soil that doesn't drain water well. After a rain the water will sit in the soil for a longer period of time than other soils. When clay is used for back fill against the foundation can cause hydrostatic pressure to build up against the concrete resulting in cracks that can allow the water that builds up in the clay to leak into the house in some cases. Initially it caused the largest retaining wall holding our house to crack in two places.
The house is build into the side of a hill over looking fields and wooded marsh.
The initial retaining wall was not designed for clay soils, it did not have accommodation for water drainage nor did it have deadman construction or specifications to handle the weight per sq. inch needed when building in clay soil. The foundation was in at this point for one year.
Powell tore out the wall, rebuilt the wall with a larger footing and back filled with clay again. In the photo you will note that the side walk to the side door was lost and had to be replaced. Four days following the back filling (with clay soil and no design for it) the new wall developed another large crack. When I went to Powell with this concern I was told that cement cracks. I asked him for the name of his structural engineer. I phoned the engineer he came, wrote a report delineating the problems and recommended that a new wall be put in with deadmen, gravel be used along side of the garage poured wall, and drains to be placed to take the water away. The third wall that was structurally engineered it held.
The cost for the engineered design was $800.00.
We had a basement leak in the spring of the first year we had been in the house about 4 months. The spring was excessively wet and a large crack in the cement occurred do to poor drainage secondary to the clay next to the foundation. We had the roof water diverted, Powell filled the crack and there has been no leaking since these modifications were made.
Spring forward 6 years. Water and clay have frozen and thawed and with spring rains caused hydrostatic pressure to build up against the retaining walls on the other side of the house. Observed the cracks and separation from the foundation.
Under the garage work shop there was a substantial structural crack that extended to the footings. It occurred close to the initial problematic retaining wall.
I went out of the area for help and contracted with Nederveld Engineering a large company that do commercial as well as residential structural engineering.
Their findings: "The retaining walls were improperly constructed without adequate consideration of the retained soil absent top of wall restraint. The NE retaining wall (engineered by VanderWheel) has not moved and does not have to be replaced. This wall is performing as intended. The cracking of the NE wall foundation is related to the movement of this section of the foundation and not that of the retaining wall. The movement is the result of outward displacement of this wall due to an approximate 7 foot differential in soil height. This wall was improperly constructed whereby the effect of the forces from the lateral earth pressure or the retained soil was not properly addressed. "
Soils and Materials Engineers, (SME) soil analysis with regard to the west side retaining walls: "In general, conventional residential CIP basement wall thicknesses and /or reinforcing steel details are not sufficient for retaining walls which are not restrained at the top. Based on the soil boring's B4 and B5, the CIP concrete retaining walls on the west side of the residence were back filled with clayey and sand and clay fill. Clayey sands and clays exhibit relatively low permeability. We did not observe any edge drains behind those retaining walls. Therefore, during periods of wet weather or significant snow melt, water can accumulate in the back the fill behind the retaining walls The hydrostatic pressure resulting from groundwater accumulation behind the retaining walls can significantly increase the lateral pressure on the retaining walls. If the retaining walls are not designed to resist the hydrostatic pressure, cracking and movement of the retaining walls can occur. "
At the recommendation of Nederveld Engineering CO, Kent Company from Grand Rapids was employed to repair the foundation and retaining walls.
The most cost effective remedy was to place helical tie backs ( similar to toggle bolts) they are drilled through the wall and a large disk at the other end picks up the soil the is brought up against the wall to stabilize it.
Four helical pins were placed to secure the wall.
Helical pins where placed in the retaining wall and the crack filled. Behind the walls the soil was dug out and surface drains placed to displace the water alleviating hydrostatic pressure build up.
These large plates were placed on the other end of the 20 foot helical pins to hold the soil to support the wall and keep it from moving.
In a conversation I had with Powell I was told that cement cracks and that his home in Fox Creek was back filled with clay as all of the homes that he built there. He sold that house and the building inspector passed it even though Powell told me that there was a crack in the cement foundation. Whew! So much for building inspectors knowledge and integrity.
Powell never came to inspect the problem even though he said he would. I kept him apprised of all the findings by Nederveld as well as SME soil engineers. I did this by emailing the reports. In the end he sent me a letter that said he was sorry for my misfortune (bad luck) and didn't feel financially responsible.
The cost to me to remedy this situation was $21,800. I looked up the receipts from the original poured wall and excavating costs and it was $30,000.00.
To do nothing would result in more damage and the loss of the homes value. I feel now that the house is secure.
Any one contemplating building a home;
1. Hire a lawyer prior to getting a builder he/she will know the history on builders in the area regarding legal disputes. They will review your contract or write up one that is in your best interest. If you sign the contractors know it was written in his best interest.
2. Keep your architect involved so they know the conditions of your lot. You may need a structural engineer to secure your foundation. Contractors do what they always have done. It doesn't make it right.
3. A soils analysis.
4. Know the difference between commercial building codes and residential you will be surprised at the difference. Commercial codes are significantly better.
5. Know about redon gas, it is comes from the decay of rock. It causes lung cancer. In Fox Creek most of the people that have sold their homes have had to put in a mitigation system for radon. It can be done by the contractor when building the house it will cost a little less and will not show on the outside.
6. Know the reputation of the well driller, Anderson and son's put ours in, and put our submergeable pump in a black pipe housing. After 7 years the black pipe rusted out and literally drowned our pump. Cost to repair was $2300.00. PVC pipe won't rust and is recommended for housing the pump. Our electric bill has dropped $30.00 a month.
