Cupolas have changed in their use over the years.
In their original use, they were added to the structure of the house as a lookout point and later as a vent to give older homes and air conditioner-like feature.
But, now that cupolas are more of a decorative feature, they are simply added on top of the roof and not incorporated into the rest of the house.
This can make installation somewhat difficult, especially if you're trying to add a cupola to a peaked roof.
Typically, roofs have a six or 12 degree angled slope but where you cut into the cupola depends where the angle will be.
Before adding the cupola, know the length of your roof first.
This can be done by measuring the center line of the peak and dividing it in half.
This is where you'll measure the angle.
To do that, you'll need to create a bevel gauge from two one-by-four boards.
Line them up with the surface of the roof and lock them in this position.
To get the angle, draw a line from there the boards meet on the interior to the exterior point.
After, decide which part of the cupola will be the front and, on the adjacent sides, draw a line through the center of each side from the top to bottom.
Align this line with the bevel gauge and draw another line from the bevel gauge on one side of the cupola.
Repeat this on the opposite side.
To create the roof's angle on the body of the cupola, cut along the lines with a jigsaw.
To check the accuracy of the angle, see if the cupola is level against the roof.
If not, make any adjustments.
Between the seam of the cupola and the roof, cover this area with flashing.
As the cupola will need some support to stay on top of the roof, attach four two-by-four boards to the roof with steel or rust-resistant screws.
These will sit inside the cupola and give it more support.
After the cupola has been placed on top of the boards, nail the cupola to them.
However, if you would like to prevent leaks between the boards and roof, a water and ice barrier should be added before the flashing and boards are added.