Content

• Steps
• Tips
• What do you need

Roof slope is the ratio used to determine the slope of the roof. Determination of the slope may be necessary when it is time to repair or replace parts of the roof. Slope is the ratio of the height of the roof to the width of the base of the roof. Height refers to the vertical side and the base width refers to the horizontal side. Often, the base is taken as a width of 30 cm.

Steps

1. 1 Measure at 30 cm. Mark this length with a marker. Many levels already have these markings, but the marker mark will be more visible.
2. 2 Climb to the roof without tools. Make sure there is no ice or moisture on the roof. It is best to climb the roof on a clear sunny day when the morning dew has already evaporated. Squat down or sit on the roof to minimize the possibility of slipping.
3. 3 Before going up to the roof a second time, collect all the tools you need. Collect everything you need in one place, in some kind of bucket or belt for tools, so the tools will not get in the way and it will be easier for you to move around the roof.
4. 4 Place the ladder on a flat surface. Be careful not to damage the gutter or the edge of the roof with the ladder. Go up to the roof. The slope can be measured from anywhere.
5. 5 Pull out the tape measure about 30 cm.
6. 6 Use a spirit level to measure the width of the roof base. Holding the tape measure with one hand, raise the level with the other and place it with the bottom corner against the roof. Using the angle of the level as the pivot point, keep it parallel to the ground. Raise or lower one side of the level until you determine the horizon by the air bubble, which will be located between the two lines.
7. 7 Measure the height with a tape measure. Keep the level parallel to the ground and measure the distance from the roof surface to the 30 cm mark on the level. Remember to turn the tape measure so that it is perpendicular to the level. Write down the height.
   • It is much easier to hook the end of the tape measure onto the roof and hold your hand. If you decide to measure the height of the level, then you need to add to the measurement the length of the tape itself.
8. 8 Calculate the slope of the roof. The number obtained as a result of measuring with a tape measure is the height of the roof in relation to the horizontal 30 cm. For example, if you measured 18 cm, the roof ratio would be 18:30.
9. 9 Carefully collect all the tools and get down to the ground.

Tips

• Measurements will be much more accurate if all shingles are removed, although this is not necessary. Access to the timber frame allows corrections for surface irregularities and any possible miscalculations due to the roughness of the tiles can be eliminated. If it is not possible to access the timber frame on the roof, measurements can be taken from the inside of the roof.
• It is useful to have short shoes that will not slip. The slope of the roof can cause injury to your ankle if you wear high-topped shoes.

What do you need

• Stairs
• Level
• Roulette
• Marker
• Pencil
• Paper