Start by making an outline on the siding where you want to position the ledger board.
Flashing an existing deck with siding behind it.
The irc doesn t provide prescriptive measures for flashing other than the minimum thickness for metal flashing 0 019 in.
4 leave a gap of 1 inch or more between the the top of the ledger and the edge of the vinyl siding.
On the end that will fit into the mortar.
Cover the top edge of the vertical leg of the flashing with waterproof tar paper or house wrap.
Seal the joint with a high.
The steps are as follows.
If the sidewall is stucco or solid wood like ours and you can t open it to get flashing behind it continue the step flashing to the peak of the roof then cover the step flashing with cap flashing photo 2.
Since newer installation guidelines do not recommend caulking this joint but instead recommend leaving a small gap and flashing behind the ends of the siding i think it is more prudent to add flashings when it is possible to do so.
Insert the flashing into the mortar joint so that it fits tightly with the wedge.
Slip flashing under siding.
The flashing has two details worth pointing out.
Though it will take some dismantling and perhaps a replacement deck board or stick of siding following the recommended practices for installed ledger flashing based on your exterior cladding is the best approach.
If the deck appears to have life left in it and the lacking flashing was discovered during an annual inspection recommended then some repair should be on your to do list.
Step flashings are to be installed one per course.
Where the back flashing needs to be cut around an obstacle measure for the notch and cut with tin snips or slice several passes with a knife.
Snap a chalk line cut out the siding and tack up the ledger board.
When slipping the flashing under the siding be sure to slide the flashing to the left or right of the ledger by at least 2.
The vertical flange of the flashing is to extend up behind the adjoining siding.
Then slip flashing behind the siding covering the top edge of the ledger.
Make the outline large enough to include space for the deck boards on top the ledger and any trim boards on the sides.
The roof deck flange of step flashings are to be fastened to the surface of each shingle in a position whereby the next course of shingles will cover up hide the flashing from view.
