Fiber cement boards are caulked only when there is no metal flashing behind them.
Flashing behind siding.
Slip flashing under siding.
When it comes to flashing siding corners many builders simply use a 1x wood corner.
Then slip flashing behind the siding covering the top edge of the ledger.
Some manufacturers do not require the metal flashing therefore we caulk the butt joint to keep the pieces together and also prevent moisture.
Flush the end of the flashing length with the wall corner and secure the flashing to the framing with an 8d nail at each wall stud.
Slip the siding up and around the door.
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.
Snap a chalk line cut out the siding and tack up the ledger board.
Many times builders fail to use proper flashing at the top of windows.
Install the flashing before you finish the top of the brick wall as the flashing must go behind the siding as well as behind and under the top row of bricks that angle outward to cover the top.
Slip flashing under siding.
Here are four ways to use metal flashing to prolong the life of siding.
Even if the roof has been properly flashed against the sidewall this one hasn t water can still run down the side of the house and behind the siding causing rot.
Begin at either end of the wall and set the level middle section of the z flashing onto the top edge of the siding panel with the wider flange upward and against the wall framing.
Nail j channel for vinyl or metal siding onto the flashing.
This will ensure water doesn t infiltrate behind the flashing.
Install the first length of z flashing.
In certain instances flashing may need to be installed on the exterior of siding.
It is always recommended to install step flashing behind stucco dryvit wood panel lap siding vinyl siding cedar shingle siding etc.
Install siding on the walls down to the flashing.
Inside corner w flashing.
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.
