Expert: Bruce E. Johnson - 2/10/2009

Question
QUESTION: Hi and thanks for your help. I have an older home with a 25 X 8 concrete front porch. I want to convert a bedroom window to a door and enclose a 9 X 8 section of the porch to use as a bathroom. The porch is built with the same foundation and footings as the house. The concrete looks to be 4 or 6 inches thick. Outside of the plumbing issues, can a bathroom be built on the concrete porch? Again, thanks. Becky

ANSWER: Hi Becky, Of course you can put a bathroom on that slab.  You will probably need to level it up though.  Most porch slabs slope to the outside for drainage, sometimes several inches. But other than that, most house slabs are 4" thick so you shouldn't need to worry about that.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com

---------- FOLLOW-UP ----------

QUESTION: Thank you so much for your very quick reply.  I do have one more question if you don't mind.  Obviously there are no anchor bolts to attach the sole plate.  I've read various ways to do this.  What is your suggestion?

Answer
Hi again Becky, we have been using epoxy anchor bolts lately.  They are basically all-thread bolt material, 5/8-3/4" and around 8 inches long.  Drill into the concrete with a 6" embedment, clean out the hole, and then add epoxy followed by the bolt.  This method is preferred by most engineers lately.   You can use expansion bolts that expand when tightened.  Same prep work, drill the required size hole, clean it out, pound the bolt in.  When the nut is tightened the bottom of the bolt expands in the hole..No epoxy required.  Either of these methods is acceptable and there are others as well.  Lead shields and lag bolts work but may not be accepted by local building authorities. Please follow all manufacturers instructions when using any of the above connection methods. I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com