Caisson Foundation in the Way

[CBlaker114]

I've got a building in Florida where the architect has designed the perimeter of the building to wrap around an existing billboard so that the billboard is within about 8.5 inches of the exterior CMU wall. The edge of the existing caisson would extend about 6 inches under exterior wall. I'm thinking of using a transfer beam to span over the existing foundation because any deflection in the billboards foundation will heave my wall otherwise. However, this is a perimeter wall with the top of the caisson at grade. Is there some sort of void form-ish product that will provide the required weatherproofing here? I've attached a quickly redlined plan view of this section and a section of what I'm currently thinking.. This is sort of out of the box for me, so if I'm completely off base here don't be afraid to let me know. Thanks all.

 

[CBlaker114]

Sorry didn't get the section attached.

 

[thaidavid40]

Some compressible, closed-cell, polyethylene, isolation-joint material, perhaps?
Dave

Thaidavid

 

[GeoPaveTraffic]

So what happens when the wind blows and the sign deflects into the building?

Mike Lambert

 

[racookpe1978]

Well, at the bottom of the sign post, there will probably be still the 8.5 inch clearance.

At the highest point of the building at the worst case hurricane wind condition from the worst possible direction?

[Now, the question is: How much credit can you take for the building moving the same direction as the sign under wind loads when the sign is being pushed towards the building? 8<) Will the building ever be more flexible than the sign - so the building hits the sign when the eye has passed, and the building is being blown into the sign post? ]

 

[BUGGAR]

This probably isn't practical for you but I'll mention it anyway. In construction, when we had to erect temporary shoring columns in zero height clearance situations, we would erect them with their base plates resting on sand restrained in a steel box frame. Later, a section of the box frame was removed, the sand washed out, and the column could be lowered and removed. These are called sand jacks and possibly you could cast your transfer beam on them. Or use polystyrene foam and pour acid on it to remove.

 

[wannabeSE]

Why can't you use whatever weatherproofing scheme is being used for the building and wrap it around the area of concern? The weatherproofing needs to be continuous and some products are not compatible with others. Maybe someone could provide better recommendations if some information on the building's weatherproofing were provided. I really don't know what you are trying to weatherproof a foot beneath the finish floor.