issues flashing rough opening for window

[containercabin]

Hey all!

I made a rough opening for my window on my 12'x12' pre feb shed that is being converted to a cabin...

The issues is - because it is a prefab, the outside sheating is 1/2" plywood that has a 1/4" type of wood siding attached to it. Similar to t1-11. So when I tried to connect the flashing tape ( I used this one - http://www.homedepot.com/p/Nashua-Tape-Select-Flash-6-in-x-25-yds-Rubber-Flashing-Tape-8-Rolls-Per-Case-631001/100507542#.Ua3qQkDUn30)

to it - it didn't adhere well.... Also, there are those groves in it which  make it really impossible to flash well.

any advice? Maybe I should put some treated 1x6 around opening and connect to that? or you a different flashing tape?

Any advice will be great.

[Redoverfarm]

Normally the flashing is put on the sheeting and then to finished siding over that.  You may be able to use a rigid flashing slipped under the 1/4 on the top and then use the tape for the sides and bottom.

[MountainDon]

Converting a pre fabbed shed to a cabin has some disadvantages, installing windows is one of them. Use a nice bead of good caulk around the opening and under the fins. Rub caulk over the nails/screws that secure the fins. Install some trim like 1x4 of something. Pattern as so...

__________
|             |
|             |
|             |
|             |
|             |
|_______ |

That will help the trim make the water run around the window. sort of.

G/L

[GSPDOG]

None of the flashing tapes will solve that issue as mentioned earlier they are designed to go under the sheathing.  As pointed out earlier caulk may be your easiest solution however depending on your weather it is not gong to hold p for long, metal drip pan might be an option.  Or remove the panel put house wrap in that section flash it then seal it up a little extreme but effective.