I was called to a home in Rochester (actually I was emailed to visit this home)to examine recently revealed rot and offer solutions.This home has a second story roof overhang that is almost four feet deep. The homeowner started to find some problems when he ripped up the cement pad that was underneath the entire overhang. The columns had entirely rotted at the bottoms – the home was built before pressure treated wood- so we replaced them. We also replaced all of the fascias with pvc trim and installed seamless gutters and leafguards to manage the water. This proactive homeowner also found some soft and punky plywood after removing some of the siding, himself, to see what was going on.
In photo #2 you’ll see that the major problem I identified was the lack of elevation between the finish grade under the overhang and the wood framing, plywood, and siding. The current building code calls for a minimum of 8″ of exposed masonry between finish grade and framing and plywood. This is to protect the home from water damage and insect damage. With the extra wide roof overhang, there is little threat from water, but major threat from insects. The reason there was no prior insect damage was because the concrete pad was poured right up to the siding. When you’ve seen the devastating damage an underground colony of termites can silently wreak on the framing of a home, you evaluate these situations from a different angle.
In this drawing that I scanned and included with my original work proposal you’ll see 2 things: First, the solution that I’ve been using for a few years now to solve this type of problem; and second, my pre-K art skills not so proudly on display! The foam gasket and the bead of caulking work together to try to form an airtight seal to keep the bugs out. Additionally, we’re wrapping the bottom edge of the plywood with ice and water shield in order to hide the plywood from the insects. I’m no entymologist, but I assume that insects will be far less likely to begin nibbling away at petroleum based products like ice and water shield. The foam gasket must be buried under the ice and water shield. I’ve seen carpenter ants eat away an entire wall’s worth of 1/2″ foam board that lay directly under the siding. The only evidence remaining to prove that it ever existed was the foil facing.
In photo #5, we applied the 7/16″ x 1″ wide foam gasket to the bottom edge of the back side of the plywood. We then began to wrap the bottom edge in ice and water shield. What I did was to gently pre-slice the paper on the back side of the ice and water shield so that I could stick it to the back of the ply and to the foam, but leave the protective paper on the part that will wrap up the front face of the ply.
In photo # 7 this is the installation of said plywood panels. Notice I ran the ice and water shield past the first piece of ply, so that I could have good overlapping with the next piece. The process calls for smearing the bottom edge of the ply into a thick bead of high grade caulking. In this case, the local lumberyard didn’t carry Lexel brand caulking (in my opinion the most bad posterior caulking available), so that means 2 things: First, we used Phenoseal translucent caulking (goes on white and dries translucent); second, Ricci Lumber needs to think about opening a satellite location in Rochester, or I need to plan ahead and schedule for them to deliver my sundries along with the lumber order next time. Phenoseal is also amazing, it has my 110% confidence.
In photo # 8, note that it’s important to nail the bottom edge of the ply approximately every 6″. Also, remember to set the depth of the nail gun so that the nails don’t just blow 1/2 way through the plywood.
By John Bradshaw
In summary, when repairing rot in New England, or elsewhere, we must evaluate whether standard operating procedure will suffice. In this case, just nailing up plywood would handle the repair, but not protect the home for the long term. Invest the extra effort to think about and evaluate what forces will be working against the project in the future. Then, find or create the solution that will stand against these forces. It’s an investment you will not regret.