# Question: How do I work out what percentage of my roof is flat?

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## How do I know what percentage of my roof is flat?

If you’re unsure what percentage of your roof is flat, you can check the surveys you had done when you bought the property to find out more about any flat roof areas and their pitch. Alternatively, use Google Earth to view your home from above and work out how much of it is flat.

## How do you calculate roof percentage?

Divide the rise of the roof pitch by the run. The resulting number is the percentage gain of the rise to the run, which in most cases will be less than 100. To get the ratio for that roof, multiply that percentage by 12 and use it in the place of X in the run-rise ratio, X:12.

## How do I calculate the slope of my roof?

How to Calculate Roof Pitch in Degrees

1. First, you need to measure the run of your roof. …
2. Next, you need to figure out the rise. …
3. Now, divide the rise by the run. …
4. Then, divide 1 by your tangent.
5. Finally, multiply this result by 180/π and you’ve calculated your roof pitch!

## How do you measure a flat roof?

To calculate your roof area, simply multiply your roof length by your roof slope height, and multiply this by two. This should give you the total area of your roof, not accounting for a chimney or other sections of your roof not covered by tiles.

## How do you work out the pitch of a rafter?

the rafter member will be longer. Pitch – Is the incline of the roof represented as the ratio of rise to the span (twice the run). For example, if the roof rises 4 feet and the span is 16 feet (twice the run), then the pitch is 4/16, or 1/4.

## What is pitch of my roof?

The angle, or pitch, of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally. For example, a roof that rises 6 inches for every 12 inches of horizontal run has a 6-in-12 pitch.

## Can roofs be flat?

A flat roof is a roof which is almost level in contrast to the many types of sloped roofs. The slope of a roof is properly known as its pitch and flat roofs have up to approximately 10°. Flat roofs are an ancient form mostly used in arid climates and allow the roof space to be used as a living space or a living roof.

## Do flat roofs have a slope?

What Pitch is a Flat Roof? If flat roofs are to work well, they have to have a slope, known as a fall, to shed rainwater. The fall should never be less than 1:80 and preferably about 1:40.

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## How do you calculate roof area on plan?

To find your roof’s total square footage:

1. Measure the length and width of each plane on the roof (including dormers) then multiply length times width.
2. Add the square footage of each of the planes together.

## How do you slope a flat roof for drainage?

For drainage purposes, the current building codes require a minimum two percent slope or a one-fourth unit vertical for every 12 units horizontal. In other words, the roof must slope one-fourth of an inch for every 12 inches.

## How do you calculate square Metres?

Multiply the length and width together. Once both measurements are converted into metres, multiply them together to get the measurement of the area in square metres.

## What is a 12 6 roof pitch?

Roof pitch (or slope) tells you how many inches the roof rises for every 12 inches in depth. An Example of a roof pitch would be a “6/12 pitch” which means that the roof rises 6 ” for every 12″ inward towards the peak (or ridge).