If the doorway has moldings measure from outside edge to outside edge to determine the proper door width add about 4 to 6 inches to your measurement.
Measure for sliding door.
Using a tape measure begin at the left edge of the opening and measure straight across to the right edge.
Cut away all the old silicone and paint attached to the door.
Pull out any.
Then you will want to measure the height of the doors as well again do three measurements one from top to bottom on the left one in the middle and one on the right.
Do this across the bottom middle and top.
Measure this edge on the door frame known as the jamb as well.
Write down the measurement.
The average widths for three panel doors are nine feet and twelve feet.
Custom built sliding glass doors meet and or exceed these measurements.
Insert a utility knife around the door frame and break the silicone seal.
Move halfway down the opening and measure again.
Again depending on the style of your home measure from the header to the bottom of the door sill siding to the bottom of the door sill or edge of the stucco to the bottom of the door sill.
To measure the height of a sliding patio door extend your tape measure vertically.
If your sliding screen doors are missing determine width by measuring from inside of side jamb to center of stile on opposite side just short of where the stationary glass begins.
For the height measure from the top of the bottom track into the top u channel see the diagrams below.
Measure from the top of the track at one end of the door down to the threshold on the ground with a tape measure.
Ideally the door will cover 2 to 3 inches beyond the opening on each side.
These numbers should be close to the same but it can be helpful to know both of them.
Remove the slider door trim with a crowbar.
How to measure for replacement sliding glass patio doors.
Be sure to capture both width and height measurements.
Measure vertically the same way from where the header meets the rest of the home to where the bottom sill ends.
Hold a tape measure to the edge of the door and record its thickness.
You ll want to measure the width of the door at the center running your tape measure from siding to siding stucco to stucco brick to brick whatever material outlines the sides of your sliding door.
The average widths for two panel doors are sixty inches seventy two inches and ninety six inches.
The most common thickness is 1 75 inches 4 4 cm.