Most rooms in an average house are rectangular with four walls, a flat floor, and a flat roof. The same cannot be said of the average ceiling. The surface is sloped, often with gable overhangs, perhaps with an overhang and gutters. Understanding plans when it comes to roofing requires a bit of homework.

If you’ve ever tried to read the blueprints for a roof plan, you may have found yourself overwhelmed trying to decipher the mess of thin lines and awkward angles. However, diagrams become less complicated when you know more about them. Explore these tips on interpreting roof plans:

Demystifying Roof Plans

RoofGenius.com offers some very helpful tips for making sense of roof plans. These suggestions are not exhaustive, but they should help dispel some of the mystery behind these architectural hieroglyphs.

Tip 1 – Check the Scale of Your Roof

The most important step is to verify the scale of your roof plans. If the schematics say 1/8-inch scale, this means that each inch equals eight feet. Similar ratios exist for metric users.

Tip 2: Determine the slope of your roof

To determine the exact pitch of your roof, you may need to climb on top of your house and use a level and ruler to measure how many inches the roof rises for every inch it overhangs. A slope of 6/12, for example, means that the roof rises 6 inches for every foot it goes up.

Tip 3: square the ceiling

If your ceiling has a lot of cracks, nooks, and wings, simply square off as much as you can by dividing the ceiling into rectangular sections. A cross-shaped roof, for example, is really just one long rectangle with two smaller rectangles on each side. This makes measuring much simpler.

Once you get the hang of it, reading roof plans isn’t that hard. Once you learn how to do it, you can easily understand the structure of many types of roofs.