Bifurcated Carrots

A little more than two years ago now I posted about my house foundation. I wonder how many readers have been around that long and were paying enough attention to remember that post! What’s really funny is how the picture from this original post was indexed by Google. Have a look at the Google images search for House Foundation and see if you can find the picture of our foundation.

Anyway, it’s time. I’ve waited as long as I could, but the city says it has to be done now or the houses will collapse. I turned in the application for the building permit today, and it’s time to start the great paper chase before doing the actual work.

Ours are the two dark colored houses in the middle of this picture, with a straggly looking grape vine going up the middle. They are open on the inside and fully joined together, only the outside makes them look like two houses. The discerning eye may notice the orange glow of a growlamp in the upper right hand window where I have started my seedlings.

The two houses were built at the same time around 1680 when our neighborhood was built, making them 328 years old. Our neighborhood, the Jordaan, was the first major expansion of the city outside of the heavily fortified original center.

At the time the average person had 8m2 of living space or about 86 ft2! The city expansion was desperately needed. The houses were built during the peak years of the Dutch East Indies Trading Company, the money from which is almost certainly what funded the initial construction.

The houses were built on a wooden foundation, with 4 meter long piles. This wooden foundation was built entirely under the outside walls, no part of the foundation extended toward the middle of the house. Until the 1930s, the house had a dirt floor on the ground level.

The new foundation will be built with concrete piles made by driving hollow pipes into the ground and filling them with cement. These will be placed in the middle of the house on the ground floor and steel rods will be placed across the top of them extending into the walls and in turn stabilizing the structure.

The reason the foundation lasted this long was because as long as wood stays wet and isn’t exposed to air, it won’t rot. Our house was built at sea level, with the foundation below sea level. Because it was submerged, it never rotted.

All over The Netherlands, but in Amsterdam in particular, is the problem that where there is land protected and drained by canals and dikes, it sinks slowly over time. That’s whats been happening to our house which has sunk an average about 1mm for every year of it’s life. As you can imagine, things were starting to get out of hand after a while, not just with our house but the whole city. At some point in the course of managing the water and ground levels, around the 1950’s, the city made the decision to lower the water level to the point where most wooden house foundations were exposed to air, including ours.

All over the city now house foundations are rotting and being repaired.

Our new foundation will be built to around 14 meters where there is a stable ground layer, instead of the original 4 meters, meaning our house won’t sink anymore.

I don’t know if I can take a lot of pictures of what’s going on, but I will at least post from time to time about it.

In case you are wondering what a home repair like this costs, let me assure you just thinking about it is making my eyes water. The total costs aren’t known yet, but this looks set to be more money that I have ever spent in my life with the exception of the initial purchase of our house. There are some subsidies for this available from the city, but I have been warned not to expect too much.