The roof pitch on a manufactured home varies based on it being a single-wide, double-wide, or even modular.
Roof pitch is simply calculated as follows. 3.5/12 pitch is 3.5 inches of rise per 12 inches of run. A 5/12 would be 5 inches of rise for 12 inches of run. Many manufactured home builders will even do 6/12 or 7/12 pitch roofs.
Low-Pitched Roofs: On a single-wide home, the roof can be considered flat since it is typically under a 3.5/12 pitch. These roofs can be "and many times are" metal. Water run off on 2.5 to 3.0/12 pitch roofs have a tendency to be higher maintenance, or at least get more frequent roof damage. This is why many single-wide builders are now doing asphalt shingled 3.5/12 pitched roofs, and even a dormer over the front door. Once you get to 3.5/12 or greater, you will start seeing the use of asphalt shingles, dormers, roof colors, and a whole family-plan of options s. At Home-Mart, their exclusive "Masterpiece" line built by Fleetwood Homes has the 3.5/12 pitch, Dormer, and 8.5 FT walls. This adds 1-1.5 FT of ceiling height to what usually would be a 7 FT ceiling in a single-wide home.
High end single-wide homes that come with higher pitched roofs, taller side walls, Dormers, energy efficiency packages, and 16x80 or even 18x80 are really becoming the new trend!
Medium-Pitched Roofs; are 3.5/12 pitch to 7/12 pitch. These are much more common on manufactured HUD Code, or IRC Modular Homes. Picture to the right is of a 6/12 pitch on a HUD manufactured home. Many times the 5/12 and up pitch will also allow the homeowner attic space to store items. This would be for modular homes. A HUD code home will will have the space, but the code prevents the homeowner to floor an attic at the plant. I see homeowners doing this as an after market feature, and it is becoming more common.
When having a manufactured home built, those who want the features of 8.5-9 FT walls inside, typically do not have a roof pitched over 5/12. The picture of the Franklin Home has 9 FT interior walls,l and 5/12 roof pitch. This makes a home very dramatic, and it sure stands tall on the homebuyers land. However, when doing the higher pitched roofs on Manufactured homes, it eliminates many builder/manufactures to do other unique features like dormers,. This will many times then be an after market event.
All the manufactured homes with a 5/12 or greater pitch, will have to also be hinged and raised at the home site. When doing this, the roof is raised, and a roof cap is then placed at the crown.
