Buttercup01, This product is made to protect your deck's substructure. It has not been tested for use with vinyl windows or siding.
JimB, Yes, you can. Please read and follow the manufacturer’s installation instructions for more details.
I used this tape on existing joists that were damp, but not wet with water. I first lightly sanded the joists to remove old dirt and grime and the tape stuck to the damp joists extremely well. Once the tape was exposed to direct sunlight and higher air temperatures, it stuck so well, it was almost impossible to remove.
Yes, as long as there is the slightest overlap of the tape, the tape will stick together and form an very good bond that will prevent water from penetrating. If you let the tape be exposed to either direct sunlight or high air temperatures, the butyl on the tape seems to "melt" into the other tape when it warms. I found if you accidentally allow the sticky side of the tape to touch the top of another piece of the tape, it is almost impossible to separate without tearing the tape.
This Butyl tape is specifically made for covering wooden joists, so I assume you plan to use it for that purpose. As Azek Harvest decking is a Timbertech product, it is made from recycled plastics covered in a PVC (Polyvinyl Chloride), an inert plastic material. I do not believe there would be any danger from a chemical reaction between the plastic decking and the tape. The adhesive is on the back of the tape itself, which appears to be of a plastic nature, and does not contact the decking. I have used this joint tape under Trex decking, which is similar to the Timbertech products, and it was recommended by Trex to install the tape to prevent rotting and decay. The tape sticks very well to the joists and once the sun heats the tape, the tape is securely "stuck" to the joist and very difficult to remove. I would recommend using the tape as it does the intended job without any safety issues that I am aware.
I'm a vet - what I learned is that we can only get a discount if the item that we're buying online is ALSO in stock at a store. I'll buy online, and then at a later date bring in my receipt to get the discount. Sometimes I'll do in-store pickup, so that I can do a quick pickup and then get the discount all at the same time.