Over the Thanksgiving break Tim and I worked long and hard trying to get the roof completed. Everything we did took four times longer than expected and while we managed to make good progress, there still is not a roof on the Bodega. The end is in sight however.
The soffits are made from 3/4 plywood with 2×4’s screwed to them. They were constructed in 8 foot lengths and screwed on to the building with 8 inch headlok fasteners. They are a bit cantilevered since there is only foam behind them. The strapping holding on the foam will join up and form a brace that prevents them from bowing under load. When the final layer of roof sheeting is screwed on it will provide additional support. Even without the strapping, I was able to sit on them without any serious bowing.
To trim the soffits to length, we used the front and back overhangs as a guide. A string was tied between the front and back ans we used it as a trimming guide. As part of this process we compared the left to right overhang to see how even we are. It turns out that the left side has 1/2 inch less overhang than the right side. I suppose we could have extended one side but I doubt anyone will notice 1/2 inch difference…it did not seem worth the trouble.
With the soffits installed, we began the task of installing insulation. The overhangs for the peak seemed to have settled and we actually had to unbolt one to get the foam under it (another hour wasted on the unexpected). With the peak on, the rest of the insulation went as expected. I used 3 inch wide Zip tape to seal the seams between sheets.
To secure the foam to the roof, I used 1×4 strapping with headlok fasteners. To prepare the strapping, I used a 3/4 inch spade bit to provide a counterbore for the head of the fastener. Then I drilled out the center with a 1/4 inch drill bit (you don’t want this to split). Fasteners were placed every 24 inches with the ones on the edge being set in 6 inches.
Installing the strapping is tricky because you must get the fastener into the roof joists. Unfortunately, the roof is covered in Ice and Water shield so there is no way to see where the joists are. A stud finder is a useless POS when dealing with Ice and Water covered sheating. The solution Tim and I devised (might have actually been Tim’s idea first) was to drive in a short drywall screw from the inside on either side of the joist. On the roof side the midpoint between the screws is the joist. You then mark the spot and keep transferring it to the insulation sheets as you install them.
As the strapping was installed, Tim watched from the inside and told me which way to move the fasteners that had missed. On a miss all that is need is to lean the fastener in the direction you need to go. By “leaning” the fastener you can adjust its position by an inch and sometimes over an inch.
Originally I planned to used 6 inch deck style screws. As we worked with them, it became clear that 6 inches was not enough to get a good hold in the wood. I scanned the internet for a source of 8 inch deck screws and came up empty. It seems that 6 inches is the longest “deck style” screw you can buy. I made the executive decision to use Headlok fasteners instead (I really like them).
Naturally it was 2 days before the holiday and I needed to find someone who could ship them in fast. A place in WI had them and could ship in time but it was going to cost me $480. Before I hit the “place order” button I did a quick search on Amazon and hit pay dirt. There was a supplier with two buckets of 250 pcs for $136 with Amazon Prime Shipping! For $290 including expedited shipping I had 40 pounds of 8 inch headlock fasteners on my doorstep the next day! My Amazon Prime account costs me $79 per year and saved me over 100 bucks on shipping for this one order….worth every penny!
The 8 inch fasteners work fantastic for attaching 4 inches of foam. If I were doing 2 inches of foam the 6 inch fasteners would have been fine….live and learn. I now have 2 cans of gold colored really long deck screws as a memorial to this project.
The soffits are on and one side is fully insulated. I have a small amount of trim work to do on that side and it will be ready for sheating. The other side still needs insulation but the first tier was installed when I did the peak so it should go fairly quick.
Next weekend I hope to get that side insulated and trimmed. Then we begin sheating which I think will take another weekend day to complete. Then I’m ready for felt paper and shingles. This roof is taking forever!!!