Expert: Bruce E. Johnson - 2/13/2009

Question
I am going to build a home and I am curious what is the best way to attach the joists to the block foundation.  I have never seen this done and I want to know how to do it correctly.

Answer
Hi Darrell, your masonry wall will have a u-block for the top course filled solid with concrete.  Embedded in this concrete while it's wet will be anchors to hold down a pressure treated 2x8 mudsill.  The anchors can be Simpson strong tie strap type anchors which you bend over the mudsill and nail or the anchors can be J-bolts that stick up two inches and which you use to bolt the mudsill down with.  Once the mudsill is bolted or strapped to the foundation then you clip your floor joists to this using a simpson H-clip of the appropriate size.  The H-clip nails to the face of the mudsill and to the side of the joist. This is the more common method. However you can skip the mudsill and anchor the joists directly to the concrete using a Simpson truss anchor strap but you will need to protect the bottom of the joist with a metal seat (only pressure treated wood should sit directly on the concrete). Visit the Simpson Strong Tie (www.strongtie.com) website and you can look at the various straps and anchors available to meet your individual criteria.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com