Some will choose to keep their pre existing flat roof on their structure underneath the new pitched roof to save removal costs but others might not be able to consider that option.
How do you pitch a flat roof.
Tear off the old materials and apply roof sheathing.
Various styles of a pitched roof can be built or you can purchase pre manufactured trusses.
How to make a flat roof have a pitch general steps step 1.
Most people view pitching a flat roof as a tedious job.
Depending on the climate your flat roof will only last between 15 and 30 years if well maintained.
A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
You will need to ensure that you are in standards with your local building codes and have the permits required.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
How to calculate roof pitch.
The way pitch also known as roof slope is measured is rise over run.
However flat roofs require much more aggressive and consistent maintenance than a pitched roof.
Determine the roof span and pitch.
Flat roofs also don t last as long.
Roof pitch refers to the slope which the rafter creates.
So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12.
Install the new material.
Pitch tan angle where angle is the roof pitch expressed in degrees.
You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof.
Rise run pitch where pitch is expressed in percent.
Minimum pitch for metal roof the minimum roof slope for metal roofs is dependent upon the roof profile.
Rafter rise run from the pythagorean theorem.