Expert: Bruce E. Johnson - 10/4/2009

Question
I have a 1959 to 60s home in South Florida with an attached carport that I wish to enclose as a garage. There are pillars and lintels attached to the main house holding up the main roof, so I'm not dealing with adding supporting walls. Those columns already have footers, so I cannot see needing any other footers. I was thinking of pressure treated 2x6 and plywood. Where can I get architectural plans to submit to the city? Can I do this as an owner/builder? What do I need as far as waterproofing at the plate? Can I use Tapcons to secure the wall sections to the existing concrete block?

Answer
Hi Gilles, you can draw and submit your own plans to the building department and do your own work as a homeowner.  However, with the South Florida Building codes being what they are you will also need an engineer (a P.E) to sign off on the structural plans and show the wind speed calculations for the structure you are proposing. You will also need Dade County product approval on all your windows and doors to meet wind load requirements.  Although your carport may support the roof structure at this time, by adding walls to it may change the way the structure handles wind resistance.  Because of hurricanes it has become important for projects like this to pass the engineering muster necessary to withstand high winds.  You can try to draw up a simple plan and take it to the building department but I am pretty sure they will want an engineer to sign off on it.  As far as your walls go, you will have to secure the bottom plates to the slab using 1/2" epoxy bolts every 32-48"..as far as waterproofing goes, it starts with a good bead of urethane caulking underneath the wall plate as it is bolted into place.  Your wall sheathing and wall waterproofing will provide the rest of your weather protection.  We have been using Tyvek or Typar house wraps with peel and stick rubber flashings around the windows and lapping over the bottom of the wall at the slab if possible.  Yes you can secure the walls to the masonry with tapcons but again, an engineer's design may be needed to denote the size and spacing of the tapcons for the new wall connections.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com