Foundation problems

[^woody^]

As a lay man, my question is why isn't it best practice to match the foundation types... So in this case, build the extension on a raft so that they all float together. Seems like a recipe for trouble doing anything else?

A raft is as the name suggests, designed to float on the ground. It's not just about case of settling, but regular bobbing up and down over the seasons.

Two rafts, especially of different sizes, loads and locations, will move differently not as one. So you're no better off matching the foundation type.

 

[paul865]

The roof structure can be fixed, but the cover flashings designed to accommodate movement while maintaining cover. Covers at mono gables to. Or an exotic steel bracket that slides, could hold the roof structure.

Thanks for that info