The slope of the roof from the proflist - how to choose the right one?

To ensure that the roof reliably protects the house and has served as long as possible, when it is erected, it is necessary to take into account the angle at which it will be built in relation to the house itself. The climate, the wind rose, the abundance of precipitation in the inhabited zone where the house is built is of great influence. But also important is the material that will serve as the roof.

How to calculate the angle of the roof, if the profile sheets( profiled sheet or corrugated board) are chosen as the roofing material?

First of all, it should be noted that the roofing of the roofing sheeting is ideal if the length of its slope is less than 12 meters. It is important when laying corrugated board on the roof to comply with all the requirements of SNiP, in which the use of wall, universal profiled sheet, as well as a profiled sheet for overlapping and with a wave height of more than 20 mm is recommended. When choosing a profiled sheet, it is necessary to comply with the compliance of its polymer coating with the characteristics of the climate.

Guidelines for slope on SNiP

It is already taken as a rule to measure the angle of the roof in degrees or percentages:

One degree is 1.7 percent, and 45 degrees is 100 percent.

The higher the angle of the roof, the less pressure it will have on snow in winter, and the water will be drained more quickly in the summer. However, the influence of rose winds( in other words - the sail surface of the roof) is significantly increased. If the slope of the roof is insignificant, then the effect of the wind will decrease, but the load on the roof from the precipitation will increase accordingly, and therefore it will be necessary to think about ensuring reliable sealing and water resistance of the roofing material.

Depending on the climatic conditions in which the house is built, the angle of inclination is taken into account. Where there is a lot of rain, it's best to make a roof at an angle of 45 degrees, so that rain drops or snow do not stay on the roof. If the terrain is dominated by dry and warm days, then the angle of inclination should be made minimal( in the case of corrugated board 8 - 10 degrees).The same roof slope will be appropriate in those areas where a storm wind is possible.

For each material there are recommendations for the roof slope.

For such material as profiled sheet, SNiP recommend a degree of gradient of 20 degrees( 36.4 percent).This is an ideal bias for the profiled sheet. But the roofs on the houses are made different and not always the angle of their inclination is 20 degrees. Therefore, there is a minimum permitted amount of roof slope for each material selected for the roof, including profiling sheets.

The minimum gradient of the roof pitch from the corrugated board for industrial or household buildings is 8 degrees( 14.1 degrees), for residential buildings - 10 degrees( 17.6 percent).If the roof will be stacked in several layers( for example, in two), then these figures will increase, that is, the angle of the roof slope must be increased in order to prevent the accumulation of moisture at the joints of the corrugated board.

The smaller the angle of incline, the wider will have to do overlapping sheets, because of which the effective area of ​​the material will decrease. So, for example, with a slope of 35 gr.the overlap must be equal to 15 cm, from 15 to 30 grams.- 20 cm, less than 15 degrees overlap two waves of the profiling sheet, and its joints( both longitudinal and transverse) can be sealed.

profiled sheet fastening process Calculations for calculating the slope angle

To calculate for calculating the angle at which the roof is inclined, an inclinometer is often used - a specially designed device. But there is an opportunity to make calculations independently, armed with knowledge on trigonometry.

Here the rectangular triangle formula is useful. The katets will represent the gap between the ridge and the overlap and the gap between the cornice slope and the center of the overlap. Hypotenuse is the bevel of the roof, measured in a straight line. Having learned these distances and applying a trigonometric function to them, it is possible to easily calculate the smallest value of the angle of inclination of the roof.

By dividing the height of the ridge by the length of the bevel, we obtain the sine of the angle of the roof slope. Using calculations on the calculator, its value in degrees( percent) is determined. If it is more convenient to use the cosine or tangent function, then the ½ width of overlap and the length of the roof slope or the height of the ridge and ½ of the width of the overlap are applied.

Please note

1. For any material used as a roof, it is important that it does not retain moisture residues from precipitation. Therefore, you need to properly install a drainage system. Even at the planning stage of the desired roof slope, it is necessary to ensure that the drainage is directed to the funnels that receive water( when the water collection system is internal) or to the special troughs( when the water collection system is external).
2. This is of particular importance in the case where the size of the roof slope has the smallest permissible value.
3. If the angle of the slope of the roof is less than 10 g., The roofing material must be membrane - it will protect the material used as the roof from the impact of damp, and therefore the material will not be spoiled.
   

   Creating roof ventilation

4. The smaller the roof slope, the wider the clearance needed to ventilate. Experts recommend making it at least 50 mm.
5. When laying the corrugated sheet on the roof with the smallest angle of inclination, it is important to observe the correct size of the overlap and the fixing steps. If you follow all the rules of laying the material, the roof made of corrugated board will last a long time and will provide reliable protection of the structure. If there is no confidence in their abilities, it is best to entrust this matter to professionals.