Is a foundation unrepeatable?

1. At the risk of belaboring Eph 2:20: a foundation has a horizontal dimension as well as a vertical dimension. Cessationists focus on the vertical dimension. I believe their argument goes something like this: according to the law of superposition, the bottommost layer is the earliest layer. The foundation goes down first, then upper stories may be erected over the foundation. The foundation is unrepeatable because it's inaccessible. The foundation is covered by upper layers. So there's an irreversible bottom-up process. 

2. But that's a fallacious inference:

i) Sometimes the foundation is exposed. Take a dirt floor. Many 1C buildings had dirt floors. Nothing was built directly on top of that foundation. Rather, there's space between the dirt foor and the ceiling. 

ii) Even if the dirt foundation is covered by tilings, that can be washed out by a flood. Cf. Mt 7:26-27.

iii) Likewise, even if a building has a rock solid foundation, an earthquake can buckle the foundation. 

So even in reference to the vertical dimension, there's nothing inherently permanent or unrepeatable about a foundation. After a natural disaster, rebuilding may require a new foundation. 

iv) Now a cessationist might object that Jesus and/or the apostles didn't build the church on an unstable foundation. In a sense that's true, but it's not something you can prove from Eph 2:20. At best, you need to supplement Eph 2:20 with something else (e.g. Mt 16:18).

v) Moreover, even that has to be qualified. How many churches planted by apostles still exist? How many 1C house churches still exist? Compare the state of 1C Christianity in Greece, Asia Minor, and the Middle East with the 21C state of Christianity in those locations. The gates of hell often prevail at a local level. 

3. In addition, a foundation can have a horizontal dimension. If the original floor plan becomes too cramped for the occupants, the foundation can be extended along one or more sides. The original foundation can be expanded, adding new side rooms. Pushing walls back. A foundation has an outward dimension as well as an upward dimension. And the outward dimensions aren't necessarily confined to original floor plan. 

4. Finally, a foundation has both spatial and temporal dimensions. Foundations at different times and places. The Great Commission lays new foundations at different times and places or extends the foundation to different times and places. By itself, a foundation is a flexible metaphor–vertically, horizontally, spatially, and chronologically. 

A cessationist might object that even if a foundation, considered in isolation, can be extended or multiply laid, a foundation in combination with the apostles and prophets cannot, because that had a 1C expiration date. But in reference to Eph 2:20, that begs the question. The point of quoting Eph 2:20 in the first place was to prove the discontinuance of apostles and prophets. So that must be derived from the text rather than treated as a given.