This measurement will help you.
Installing an attic tent.
Measure the inside width and length of the rough frame then pick the attic tent closest in size.
Attic tents can vary in size but you do not need exact measurements in order to install them properly.
Installation of an attic tent is relatively simple.
Installation of this type of attic ventilation involves leaving a gap in the sheathing along the ridge and covering it with a perforated vent.
Using roofing nails secure the base and seal the nails with roof cement source.
Use plastic roof cement to smooth the vent base and then place the base over the hole.
Next measure the access way you will need the inside width and length of rough frame.
Static vents often protrude from roofline thanks to.
Do it yourself.
To ensure an easy opening of the attic tent.
Due to their flexibility you have about a 2 3 margin of error.