BratacDD
2012-06-12 12:22:57
- #1
Hello,
In a concrete foundation, the load spreads out at an angle of about 60 degrees. Below the foundation, depending on the soil conditions, the load then spreads out at an angle of about 45 degrees. If you want to prevent the load from the extension from pressing against your basement wall, the foundations must be correspondingly deep.
If you do not have existing documents for your house, it is definitely advisable to dig a test pit at the place where the extension is to be built. For this, a trench about 40cm wide (a small excavator bucket) is dug. Then you can see how deep your foundations are, for example, if there is a foundation projection, etc. Alternatively, the planner may assume the standard case for your building age based on their experience, with the risk for you that once excavation begins, there may be redesigns. These can, if you are unlucky, become quite expensive and possibly exceed the existing budget. However, by then you are already at a "point of no return."
What is a stepped foundation?
Yes, but not over the entire length; usually, you step up in increments of about 30cm, but so that the load distribution angle does not leave the concrete foundation.
Regards BratacDD
In a concrete foundation, the load spreads out at an angle of about 60 degrees. Below the foundation, depending on the soil conditions, the load then spreads out at an angle of about 45 degrees. If you want to prevent the load from the extension from pressing against your basement wall, the foundations must be correspondingly deep.
If you do not have existing documents for your house, it is definitely advisable to dig a test pit at the place where the extension is to be built. For this, a trench about 40cm wide (a small excavator bucket) is dug. Then you can see how deep your foundations are, for example, if there is a foundation projection, etc. Alternatively, the planner may assume the standard case for your building age based on their experience, with the risk for you that once excavation begins, there may be redesigns. These can, if you are unlucky, become quite expensive and possibly exceed the existing budget. However, by then you are already at a "point of no return."
What is a stepped foundation?
So does my foundation for the extension also have to be 1.5m deep?
Yes, but not over the entire length; usually, you step up in increments of about 30cm, but so that the load distribution angle does not leave the concrete foundation.
Regards BratacDD