Sulphate Attack - Options

[mogin]

I have a home built in 1912 that has a crumbling concrete foundation. An engineering report was commissioned and the diagnosis was sulphate attack. The presented options were:

1 (preferred) replace foundation with sulphate resistent concrete, or PWF foundation
2 Build PWF foundation wall inside existing concrete wall, attached to joints and anchored into slab with angle iron.

The options are further complication by these additional factors:
a - The house is considered a heritage building with significant brick and sandstone work. The brick sits directly onto of the concrete foundation. A professional house mover was contacted and the recommendation for lifting the house (for a foundation replacement) would involve removing all of the brickwork.
b - in preparing the basement (removing finishing), the slab was found to contain large crack along the perimeter of the basement, and sinking in one corner. This complicates an internal fix.

My question: is there a 'third way' that we haven't thought of that would maximize the preservation of the house, while permitting a solid, permanent fix?

Thanks!

 

[fndn]

If it is possible from building rigidity, provide temporary column suppots at several foot intervals around the perimeter and near the interior posts. Then saw cut the bottom 1 foot of concrete foundation and pour new concrete mat foundation with type v cement. After 1 week you can remove the temporary supports, place leveling support plates at settled areas for plumbness and slowly lower the house on to the new mat foundation.

You will need a structural engineer to do the shoring and temporary support design and a geotechnical engineer for the soil parameters for earth pressures, bearing capacity and settlement.

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