# How to count bias

At construction of residential buildings consider weather factors. Suddenly spilled rain can give some inconvenience, but it can be avoided if your roof is arranged in such a way that its slopes will promote removal of water and snow from roof. For providing the correct corner of slopes it is necessary to define roof bias.

1. What is bias? It is tilt angle of slope of rather horizontal surface. The bias of roof of subjects more abruptly, than is higher corner. It at construction measure in tangent size, concerning height to the basis of right triangle one to five. As a percentage usually note biases with small corner, so-called small biases (for example, flat roofs).

2. Biases measure by means of such adaptation as the inclinometer. It is rail with the frame attached to it. In rail corner between levels the axis to which the pendulum is suspended is located. The pendulum consists of two rings, plate, small weight and the index. The small weight moves between guides with cuts. On internal part of cut the scale with divisions is located. If the index coincides with zero scale, then the rail is in horizontal position.

3. The bias of roof is chosen according to the used material. Considering amount of precipitation in this area, it either is increased, or reduced. The corner of bias fluctuates usually ranging from ten to sixty degrees. The more abruptly the roof, the more on it will be required materials at construction.

4. When determining bias of roof rail of the inclinometer dispose at right angle to the fad. The index of the pendulum in this case will show the required size in degrees. These indications can be translated in percent by means of the special schedule.

5. There is one more way, theoretical. It is that it is possible to determine bias size by formula. In this case it is necessary to know fad height from garret overlapping and roof length. The formula will look so: At = Vk: Dz/2 where At is size of bias, Vk – height of the fad, Dz – length of underlay of roof. If to multiply the received result on hundred, it is possible to receive value of bias as a percentage.

Author: «MirrorInfo» Dream Team