Addition Footing Attachment to existing basement wall

[jtodd]

I am preparing to add an addition onto the side of my home. The addition will have a crawlspace foundation of block on concrete footing. The existing house sits on a basement foundation of 12" block filled with concrete. Since the footing for the existing basement is well below where the footing for the new crawlspace will be, I am wondering how to tie the new footing to the existing house. I have had two footing guys come out and one says drilling and epoxying rebar into the basement wall to tie the new footing to the wall is what he will do while the other guy says that he wants to break into the wall and install lintels. Both make sense but I am concerned about the future waterproofing issues that may come up if we compromise the basement wall to install a lintel. The home was built 7 years ago and everything more than about 2 ft. out from the basement wall is undisturbed soil but of course, the backfill against the basement wall is the concern. I have yet to talk with the inspections dept. about what they will want since it is best to have a pretty good idea of what you will do before you approach them in our county (they don't take too kindly to giving out "free" advice). Any thoughts on this from the experts?

Thanks,
Jim

[concretemasonry]

I am assuming your new footings will be 24 - 48" below the finished grade and you have a 8' or so block wall with 6" to 24" exposed. If that is the case, complete filling of all the existing block cores was not really a structural requirement, but it is often done rather for show and convenience than just filling a few cores.

Pour a 24" wide footing for the addition and tie it to the existing with dowels epoxied into the existing walls. You should probably go heavy on the dowels, because you never know how well the cores were filled with concrete since the filling probably was not required structurally.

Dick

[MCC]

Check Your Local Building Code Most Code Will Require You To Step Down To Your Existing Footings And The You Should Dowel Into Your Footing And Epoxy Re-bar. The Other Thing To Do Is Cut Out And Tie In The New And Old Wall At Leaset Every Third Course.

[jtodd]

I spoke with a structural engineer who advised me to dig down to the existing footing and drill and attach rebar 8"-12" into the footing. I checked with my local inspector and he said this is fine. Next question (and maybe I should have asked my inspector): the footings will be tied together, how do I attach the block walls together? The new walls are perpendicular to the existing walls and I want to make sure they do not separate. Any suggestions?

Thanks,
Jim

[MCC]

Simpson Strong Tie Make A Tie For Your Purpose Or You Can Just Tooth In The Block Every 3 Or 4 Courses