Im looking for the strongest concrete screws

[paulmars]

for outdoor humid, hot central florida. Strong structural concrete screws.

Im attaching simposon H10S and LGT2 straps to my rafters and cinder block walls. Im using simpson screws to attach to the rafters, however simpson makes no outdoor concrete screws and has no suggestions. So, Im looking for the best reasonably priced outdoor concrete screws for use in central florida.

thanks,

pa?

[mjr6550]

There are few structural fasteners designed for hollow concrete block walls. It also makes a difference as to whether the fasteners are loaded in shear or tension. I'd suggest looking at Simpson's masonry fasteners as well as others (Hilti, Powers, Redhat). You will generally find pretty low allowable strengths with hollow block. Other options are to bolt through the block and attach a plate on the outside of the wall.

Concrete screws (like Tapcons) are generally not approved for structural use.

[John Kogel]

I think they need to be stainless steel and maybe you need to bolt a ledger board to the block wall.

[Bill Kibbel]

Sounds like an upgrade for hurricane resistance.

Epoxy SS threaded rods into holes in the CMU walls to secure wood 2xs, then screw the Simpson ties into the wood.