Expert: Dan Griffin - 1/3/2008

Question
QUESTION: Hey Dan! Thank you for volunteering to answer questions for us, the rookie home improvement people!  I am getting ready to build a patio cover (2x6's on end with no solid roofing material) that will be attached to my 2 story home. The room that the ledger will be attached to is a vaulted ceiling great room so I am assuming there is no rim joist.  My siding is stucco over foam board.  Two questions:  Is it OK to secure the ledger over the stucco? And do I just drill my lag bolts into my 2x4 studs? I hope my questions make sense and thank you very much!!!

ANSWER: I understand your question and you do make sense, but, boy, do you have some major issues staring at you.

Issue one.  Load bearing capacity of a ledger band install of any type.  There have been some horrific death and injury cases recently about failure of single board ledgers.

Issue two.  YOu don't really have stucco, you have EIFS if this a thin cementitious finish on foam.

Issue three.  Water intrusion into the house framing at ledger boards no matter what the exterior finish.  Rotting and failure of ledger boards because of poor or no flashing.

Issue four.  Carrying and fastening a ledger board without a rim joist.

I subscribe to the JOurnal of Light Construction and they have had several articles on commercial deck failures and their causes.  I tried to find which issue, but didn't come across them.  They do reference attaching ledgers here:
<http://www.jlconline.com/cgi-bin/jlconline.storefront/477c4f05002bddbe27177f0000>
<http://www.jlconline.com/cgi-bin/jlconline.storefront/477c4f05002bddbe27177f0000>
but they don't give you the entire article, but you may want to go to the public library to reference.

The EIFS is not strong enough to carry the load and you don't want your ledger board trapping moisture between the EIFS and the ledger as it will rot out the ledger, stain the EIFS, hurt the EIFS, and allow moisture into your house structure.  You can create galvanized steel pipe "stand offs" that go from the house side of your ledger to the face of the stud.  You need to remove the materials in the way and waterproof these pipe sleeves completely.  The lags  must be in a staggered 1/3 point pattern so as not to split the ledger under load.  I would certainly install heavy galvanized fender washers on both sides of the ledger board where you plan to install the lags.  These sleeves should be long enough to provide an air gap between the EIFS and the ledger.  Plan on flashing water away from the ledger to prevent water and rot.

I suspect that this project will require a building permit.  I also suspect that the permit will require an engineering stamp as to lumber type, bearing capacity, fastening details, handrail attachment, fire egress, etc.  You probably do have a rim joist, but will need to know and you may have to reinforce its attachment as you will be pulling and pushing on it in a direction it was not designed to resist.

You might plan on making the deck as self supporting as possible with minimal attachment to the house.  This will require more columns underneath and more sheer bracing, but will reduce some of the headaches.

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

QUESTION: Wow, thank you so much Dan- Especially for the quick response!  One minor correction to your response is that there will be so live load to the patio cover but still I think you have an excellent point for safety's sake and make the structure somewhat freestanding if not totally.  I pre-poured the footings on my patio for a self standing structure but parts of this think have to attach to the house somewhere.  I imagine my best best is to design the patio cover as best as possible and then take it to the building permit office.  I plan on also making some drive-bys around construction sites.  Any other advice for me?  Thanks again- You are awwesome!!

Steve

Answer
I am very sorry, I misread your original question.  I assumed for whatever reason that you were installing a deck.  On closer reading you are installing a patio cover only.  The issues don't change a great deal, but the loads sure do.

I would still use pipe nipples to stand the ledger, at least slightly, off the EIFS.  I am confident that the lagged ledger is adequate to carry the rafter load, though you still don't want all the lags run down the center of the ledger.  I am not nearly as concerned about the roof pulling away from the house and trying to pull out a rim joist.  The loads will tend to be down and toward the house where the rim joist should be in good shape.  If it is not there, the studs should be able to deal with the loads also.

You do still have major moisture potential problems.  What are you planning for roofing?  How were you planning to flash or waterproof the EIFS/ledger intersection.  You could probably flash and cut in a counter flash, but the foam doesn't supply much substance.  There is a counterflash with a caulk trough built in that could be a fair compromise.  I would use the same nipple type instalation on the counterflash and flood the trough with a good urethane caulk.  Awnings are often installed with a caulk bead only.  This would not be my first choice.  Completely professional installation would require cutting out above the ledger to get flashing behind the house wrap and out onto the new roof.  Consult a local EIFS contractor for a recommendation.

Again, I am sorry I did not read your original question more carefully.