The Problem

The spots were dug for this exploration; 1 along the north wall, 1 along the west wall and 1 along the east wall. These spots were chosen based on the condition of the floors and walls inside and outside the building as well as the exposure they would face during excavation for the new building.

The east wall dig was done near the south wall as the south wall had an exterior crack right round through the corner column and down the side of the east wall. It’s been discovered that there is NO FOUNDATION at all. The stone that is at the bottom of the building continues down about 300mm and that’s it. The condition of the stone below dirt is that the mortar has disintegrated into dust and can be removed using your finger.

The north wall dig was done in the middle of the north wall, both columns at the north wall have cracks right down the length of them where the wall meets the column. The interior floor is cracked right across the north wall and down the east wall and where the crack meets in the corner up the interior north wall. This dig shows us there is a foundation down about 1 metre, but there is NO FOOTING. There is concrete sitting on the earth about 150, 200mm followed by a layer of mortar, which has also disintegrated into dust and can be removed with your finger, followed by rock. It is hard to tell how thick the foundation wall is at this time.

The west wall dig was done about ¾ of the way towards the north wall. This dig again showed us that there is NO FOOTING, and the foundation was about 750mm down, which shows us the depth of the foundation changes from the south wall of the building to the exterior, why this was done is undetermined, it might have been to account for the change in elevation. This is a concern because at this time we are unable to tell how the foundation changes either by stepping the foundation down OR just a diagonal slope. The foundation here is also 150 to 200mm of concrete followed with a layer of mortar and the stone. The mortar here has also disintegrated but the roots from a nearby tree have grown into the foundation and have left a hole. The stone above ground has spots of bulging and indentation, which follow the holes in the foundation, whether this is from the tree roots or the condition of the mortar is hard to tell.

The Solution

Myself along with Pat Hallows (candidate for construction) together came up with a solution. First of all the south end of the building, which appears to have no foundation needs to have some sort of foundation, we thought 500mm down and the 300mm wide under the stone already there. From there we can underpin the building doing an alternate 1m and then going back to do the alternate so that the building is never fully exposed. During excavation for the new building the north, east and west walls will be exposed and so we will wire mesh and plaster the foundation up to the bottom of the columns, which sits on a ledge. This will also deal with the stone problem as well as hold the foundation together.

I have never seen a foundation or lack thereof this bad. Pat, my contractor friend said that the building was waiting for me to save it! BUT the upside is that I am learning all sorts of problem solving and coming up with new ways to do things, which making this fun, well a version of fun anyways.