Pile Driving
The pile driving for our new foundation starts tomorrow. In the last few weeks they’ve been preparing by finishing the demolition of the old interior walls, putting up support structures like in the picture below and cutting holes in the concrete floor.
I’ve posted before a number of times about this foundation repair that’s been dragging out for years now.
The picture below is another example in a series of skeletons in the closet the contractor found. In my last post I talked about the center load bearing wall that was listing, and this is the wall beyond that one. This wall is not only listing, but it’s buckling too. You can see it has a definite concave shape with respect to the wooden supports. Since it’s also an outer wall, it can’t just be removed like the other load bearing wall, so after the foundation repair I will build a new wall in front of this one, and fill the space between the two walls with concrete, in order to harden the wall and provide enough support for the house.
In the bottom of the picture you can see some of the holes that have been cut into the concrete floor.
Here’s another example of the wall supports they are using to stabilize the house for the pile driving and foundation repair. The support will change in the course of the work. Once the piles are in place, they will be more stable than the house, so the support structure will change in order to take advantage of this extra support. Notice how they had to support the window here too? This whole setup seems a little dodgy to me, but in fact it represents weeks of work by the contractor and construction engineer, and was approved by the city as part of my building permit. It’s all been very carefully mathematically calculated and worked out.
I had to include this picture below, because there is so much going on. The ceiling beam that was burned by the flu (I mentioned this in my previous post) was cut away to make space for the support on the left. On the wall you see a number of generations of brick work, starting with the 350 year old original wall. The ceiling beams are different heights here, and you see the intersecting steel beams.
This wall below was another skeleton, and was the source of quite some consternation for the contractor. This is supposed to be a load bearing wall, and is very important for the support of the house. The problem is at some point someone took it out and replaced it with a non-load bearing wall. In other words the cinder blocks you see are not sufficient to support the house.
Well my house hasn’t collapsed yet. The contractor and building engineer know how to deal with a load bearing wall, even one that’s in bad shape. They know what to do when a wall is not load bearing. The problem is what to do when a wall is supposed to be load bearing, but isn’t…
This wall will be replaced by a steel support beam.
Of course the workers have a chance to get in on the action too. This is what’s left of my utility cabinet and electric meter after the demolition work. When you need to have electricity for music, there’s always a place and time for a little creative electrical wiring…
Holes need to be cut in the concrete floor, instead of just removing it, because the pile driving machinery has to have a hard surface to work on. This is what the holes looked like right after they cut them.
My house sits right about at sea level, and you can see the water level in this hole.
My house is actually made op of two houses joined together by breaking through the middle wall. You can tell the previous owners had different ideas on how to build a floor. On one side there was nothing but sand under the concrete floor.
On the other side, they found another concrete floor under the first one, and had to use a special drill to go through the second floor. Under the second concrete floor was a wooden floor…
The picture below is what it looked like after they finished drilling (together with my shoe).
Foundation work has begun
This has been going on for years now, and I’ve posted before about my house foundation.
http://www.patnsteph.net/weblog/2006/01/house-foundation/
http://www.patnsteph.net/weblog/2008/02/its-time-for-a-new-house-foundation/
http://www.patnsteph.net/weblog/2008/06/building-permits/
http://www.patnsteph.net/weblog/2009/03/foundation-trials-and-tribulations-and-a-bad-constructeur/
http://www.patnsteph.net/weblog/2010/03/big-projects-2010-house/
http://www.patnsteph.net/weblog/2010/03/approval/
In short, based on their experiences with other houses in the neighborhood many of which needed foundation repairs, and the outside appearance of my house, the city decided to do an inspection of my foundation in 2006 and discovered it was bad.
In 2008 I was ready to begin, but the project got bogged down with disputes with the neighbors and a technical architect (what the Dutch call a ‘constructeur’) who was trying to rip me off. Above is a link where I talk about what happened with the constructeur, but in fact this is now in court and is an ongoing issue, so I’m not going to say a lot more about it now. I’ll post more about it later. The same is true with the neighbors, things need to be a little more settled before I post details on the Internet.
So now the work has finally begun, and we’ve run into the first technical problem!
My house is built with a load bearing wall in the middle. This makes the foundation repair much more complicated, because as well as supporting the outside walls both during the work in with the new foundation, this inside wall has to be supported too. My house is 330 years old now, and this wall is part of the original house.
The problem we discovered with this wall is it’s not strong or stable enough for the foundation repair. Before we fix the foundation, we need to fix this wall. The main problem you can see is visible on the right side of the picture. Here’s a close up of that part of the wall.
You can see in this picture the wall is not straight. The piece of wood running from the ceiling to the floor is perfectly vertical. The load bearing wall however slants to the left. The measurement difference between the bottom of the wall and the piece of wood, and the top of the wall and the piece of wood is about 15cm. Literally, my house is in the process of toppling, and the stress of a foundation repair will likely just send it over if I don’t do something about it first.
Another less serious, but kind of humorous problem we uncovered was in connection with an old fireplace that used to be in this room. I think it was used to burn coal. One of the first things I did when I bought the house was remove the fireplace.
In the top picture, you can see a black stripe where the flu used to run. The silly people who installed the fireplace and flu ran it alongside the wooden ceiling beam. Below is a close up of the beam, and you can see they were starting to burn through it! I wonder if they noticed any unusual smells?
The beams in this room were rotting anyway, and have since been replaced or reinforced, so it’s not an issue anymore.
The other problem at the moment is, independent from my foundation plans, the city has decided to dig up the entire street in front of my house and replace the water, electricity, gas and sewer. Above is a picture of what the street looks like, and as you can see it’s now impossible to get any heavy equipment into the house or place a rubbish container on the street.
So the plan at the moment is to remove the troublesome load bearing wall, and replace it with a steel structure. I’ve wanted to remove the wall for some time now, and just was trying to avoid the expense when I needed to pay for the foundation repair.
Unfortunately, this is going to involve completely redesigning the foundation because the weight will be distributed differently. On the plus side, I will probably need fewer piles, because the weight of the wall won’t need to be supported in the middle, and this will save some money. The current plans include 15 piles, 21 meters deep. Hopefully, I will be able to go to 13 or 14 piles. This all needs to be done and submitted to the city for approval, and since we need to wait for the city to finish the street work, we have some time to kill anyway.
After approval from the city, what we will do is cut holes in the existing cement floor for the new piles. The way my existing foundation is built is it’s entirely under the outer walls and the inside load bearing wall. In the middle of the house there are no piles, and this is where the new piles will go. The reason for cutting holes in the existing floor instead of just removing it, is the equipment that drives the new piles needs a hard surface to work on. The ceiling clearance is a little over 2 meters, and the new piles will be made with a hollow steel case that will be driven 2 meters at a time with the sections welded together as they are driven. Then the hollow case will be filled with cement.
The piles will be driven starting with the most solid side of our house first, and as the piles go in a support structure will be built on top of the new piles, giving support to the house. When we get to the load bearing wall, a special temporary support structure will be built, allowing the removal of the wall and installation of a new permanent steel structure to replace it.
As the first piles are driven, the ground will get compacted, meaning the later piles will have to be driven harder to get them in the ground. It will be important at this point to have good support in place for the house.
After the piles are driven, the existing floor will be removed, and the ground dug out because the new floor will be lower than the existing one and the ground is seriously contaminated and needs to be cleaned. There will be some refilling of the space with sand.
After the space is dug out, they will break holes in the outer walls that the new foundation will mesh into. A new concrete floor will be poured, and this floor will sit on top of the new piles and into these holes in the wall. The holes will be 50cm wide, spaced 50cm apart, meaning at floor level half my wall will be cut away. Jacks will be placed in these holes to support the house on the existing foundation during the work, but after the cement floor is poured, the weight of the house will be transferred to the new piles via the cement floor.
I’ll be posting pictures!
Approval!
No sooner did I press the publish button on my last post than a letter from the city arrived with final approval for the last round of drawings and calculations for my house foundation. Now to get the work started!
Big Projects 2010: House
The foundation repair on my 330 year old house is finally coming together! The final plans were submitted to the city a few weeks ago, and I’m waiting for approval. I’m in very active discussions with a contractor, who I expect will do the work. If nothing serious goes wrong, work should start in about a month.
What an incredible project this has turned into! Contaminated ground, some of the most poorly behaved neighbors I have ever seen, cheated by architects, bad contractors, just everything that could go wrong has, and it has all dragged out for years now. As things start to come together, and the work starts getting done, I plan some posts both explaining what’s happening as well as what’s happened.
What you see in the pictures above are the main larger drawing of my new foundation at the top, including 16 piles 21.5 meters deep. In the blue folders are about 50 pages of mathmatical calculations that describe in detail all of the functioning of the new foundation and all the support the various parts will give. Also on the right is a new steel stability structure that will be installed in my wall to keep my house stable for the future. On the lower left are the plans for a support structure that will be used during the construction that will keep my house from collapsing when the weight is transferred from the old foundation to the new one, which will be particularly important because we’ll be living upstairs at the time.
Foundation Trials and Tribulations and a Bad Constructeur
Some time ago, on a couple of occasions, I’ve posted about replacing the wooden foundation on my now nearly 330 year old house. It’s funny how I’ve gotten so used to saying 325 years, that now 5 years later it’s a struggle to get used to the new number. Since it’s truly become the bane of my existence over the last several months, it’s time to both post an update to let everyone interested know what’s going on, and to take the opportunity to publicly tell off Duyts, the architectural bureau that’s been the biggest source of problems as of late. It’s really amazing how many problems can be caused by a bad architect!
Like I mentioned in my last post, I share a common wall with one of my neighbors. It’s a complicated and age old problem. I own the land under our common wall, and in fact a bit of the land under my neighbors house as well. I have the larger house, and my house is older than my neighbors, by around 100 years. Taking all of these things into account, the city said the common wall was my responsibility. I have to take care of providing a foundation and support for this wall, but my neighbor has to pay the extra costs associated with supporting the weight of that part of his house. In addition, my neighbor has the right to do his foundation together with mine if he wants.
While my neighbor is not very technical, and probably does not understand fully what’s going on, he said very firmly at the beginning he does not want any dependency between our houses, and he will pay the extra costs of my doing that wall, if that’s what’s necessary to keep our houses independent. It’s worth noting that my neighbor taking that decision is turning out to be a very expensive one, as I warned him it probably would be. In layman’s terms, it leaves him a house that has to be supported asymmetrically by his new foundation, as well as having to pay me the costs of supporting that side of his house from my foundation.
Then Comes the Constructeur
There are two architects working on this project. The first one, who is also my advisor and project manager, made the initial drawings of my house that were the basis of the new foundation design. The other architect is called a ‘constructeur’, and is a technical architect. He is the one who actually designs my foundation, as well as the associated building plan. He plans the number and layout of the piles, as well as how deep they have to be. This is really a lot more complicated that it might seem, given the age of my house, the common wall with my neighbor as well as all the stresses a new foundation will put on the house itself, both during and after the building work. If this is done wrong, my house could collapse or I could have long term structural problems. On the other hand all the safety supports which are part of the building plan are very expensive, and erring on the cautious side could costs tens of thousands of euros unnecessarily. A number of steel beams have to be placed before and after the work, and these have to be planned very carefully.
At the beginning we asked for a number of quotes from constructeurs, and we choose Duyts, mostly because they were the least expensive. They started by making a draft drawing of a proposed foundation, that we could use to get feedback from contractors and others, so that minor changes could be incorporated later into a final version. This draft was also used as a way to get quotes from contractors for the work, and in this way we have already chosen a contractor. This draft seemed okay, but honestly there were some problems, mostly requiring extensive work around the existing stairway that didn’t seem necessary. We also had a number of rather stupid issues, like the constructeur forgot an important support structure, during a new phase I was asked to accept extra charges that in fact we had in writing were part of the original quote, and some other smaller things that are a little hard to explain clearly here.
Then it was time. We had accepted a quote for the work from a contractor, had a tentative start date for the work, and signalled the constructeur to do the final drawing incorporating the feedback on needed changes. We were promised the drawing in a week (it was complicated enough that he probably spent most of that time working on it), and even though he was a week late he finished and sent the drawing directly to the city for their final approval before the work would begin.
The only problem was the constructeur totally changed the drawings in the meantime!
Since my neighbor who decided did not want a connection between our foundations also started work on his foundation, and choose the same architectural bureau, the constructeur decided to combine our houses. When I called on the constructeur to explain himself, explain why he didn’t let us know in advance he was going to do that, and correct the mistake by redoing the drawings, he was indignant. It was simply better, he said. He said that because he now had the drawings from my neighbor, he had new information of the situation being different and he didn’t need to tell us he was going to change anything. I’m still seething at the arrogance that lies behind a statement like that, and the idea that whatever this architect says he thinks I have to accept, because he knows better what my house needs than me.
Besides the fundamental problem of combining my foundation with my neighbors, there are other obvious technical problems in the latest drawings, including not enough space being left for my stairway, the only means of getting into my house.
Starting Over
So now I’m in a situation where I realize what a total idiot this constructeur is, I guess it’s my fault for choosing the cheapest, and I suppose you get what you pay for.
His position is still that he hasn’t done anything wrong, and while perhaps I could eventually convince him to redo the drawings, I’m far beyond that now. My house is too important for such an idiot to plan my foundation, so I will look for someone else to do the drawings and do the building plan.
Of course he is expecting me to pay thousands of euros for the incorrect drawings, which I won’t, and this may lead to confrontation in court.
Of course there is no guarantee another constructeur will be able to use the original draft drawings as a basis for my foundation, because they may be wrong or the constructeur may simply have a different methodology. This would mean the current quote that I’ve accepted for the foundation work can’t go forward, that may result in the contractor asking me to pay compensation.
It’s also very likely starting from scratch could mean it takes a month or more extra time, delaying the project that much further.
