Carport Support Posts Shifting - need help

[doyl0057]

I just bought a backsplit bungalow which is about 35 years old. Attached to the side of the house is a 1 car-carport. There is a concrete base and there are 4 - 4x4 support posts supporting the one side of the roof and on the other side it has been secured to the house. There are 4 Cedar trees on the edge of the carport which are about 30 years old. The root structure looks to be cracking the concrete. The 4x4 Support Posts are leaning away from the house at about a 8-10 degree angle. One of the middle support posts has actually come unattached from the cement footing. I am concerned that the support posts may give way and the carport roof could collapse. An engineer told me that once it reaches a 12 degree angle, I should really be concerned. So what I have done in the meantime is taken 4 - 4x4s, secured them to the existing 4x4 posts via carriage bolts, making sure the new 4x4s are snug on the cement base and I have secured them to the roof support beams.

My question is this: it is obvious the cedar trees are causing this problem and they need to go, which they are this weekend. It is also obvious the carport will need to have the cement base jack hammered out and a new concrete pad poured. Does anyone have any experience in doing this, if so, would they know exactly how I should go about doing this new pad while keeping the support posts in place?

Thanks,
Chris

[HayZee518]

a sonotube post footing seems appropriate for this installation. you must go down below the seasonal frost line for support. relying on just the slab won't do. between spring and fall the slab could heave back and forth due to the temperature differences. you say the trees will go, well this is a call on your part. the taproot for cedar trees isn't that deep, it's the branching roots that cause problems. leave the existing posts in place. dig and pour your sonotube foundation. let it cure and use post supports. install 4X4 as close to the existing making sure of plumb and fasten to the existing with screws. then remove the faulty posts.