Roof slope angle: how to calculate

Like it or not, but almost all private houses have a pitched roof, which is not surprising, since they are easy to maintain, although their device is more complicated than that of flat roofs. In order to make the roof correctly, you need to calculate the minimum angle of the roof slope, and in order to calculate, you need to know what it depends on.

However, it is the angle of the roof slope that distinguishes pitched roofs from flat ones. If the angle exceeds 10 degrees, then the roof is considered pitched.

In the event that the angle does not reach two and a half degrees, the roof is classified as flat. There are roofs with a slope of more than 80 degrees, but they are made very rarely.

The angle of the roof depends on many factors, not only natural, but also on the properties of the roofing material used.

• Wind. The greater the slope of the roof, the greater the wind load.With an increase in the angle from 10 to 45 degrees, the load will increase by 5 times. True, if you make a small angle, then the wind can tear off the sheets of the coating, falling under the joints.

• Snow and rain. With an increase in the slope of the roof slope, snow is better removed from it and water flows down. At the same time, it has long been known that the maximum snow load is observed on slopes of 30 degrees. When arranging a 45-degree slope, complete convergence of snow is achieved, while from smaller angles, the snow is simply blown away by the wind.

To your attention! If the slope is small, then the wind will try to drive water under the joints, which determines the minimum roof slope. For example, for tiles, the minimum angle is 22 degrees, for slate - 30, for rolled materials - 5.

As a result, it turns out that with a large amount of precipitation it is better to make a slope of at least 45 degrees, but if there is little precipitation, then 30 degrees will be enough.

As for the wind, a roof with 35-40 degrees will cope with normal wind indicators in the area, while in areas with strong winds - 15-20 degrees.

But with the device outbuilding on the roof it's not all that simple. more likely. will have to contact the experts.

How to calculate the angle of the roof slope

Initially, you need to correctly calculate the slope of the roof.

As noted earlier, the slope depends not only on the design of the roof, but also on the material used:

1. When calculating the angle of inclination, it is necessary to take into account the climatic features of the region in which construction is underway. The drier and warmer it is outside, the more flat roof you can build.With an increase in the angle of inclination, there will be a decrease in the accumulation of snow on the roof, which means that the snow load will be minimized. In addition, increasing the angle of inclination will increase the wind pressure, so a steep roof is not suitable for areas where strong winds prevail. Typically, the slope of the ramp ranges from 10 to 60 degrees.
2. In addition, you need to remember that by increasing the angle of the roof, you increase the cost of the roof as a whole. For example, arranging a roof with a slope of 60 degrees, you double the material costs compared to a flat roof, and a roof of 45 degrees, one and a half times the cost of a flat one.
3. It is necessary to calculate the slope of the roof as the ratio between half the laying and the height of the ridge, then snow removal from rooftops won't work.
4. The main thing to remember is that in the valley the slope must be at least one percent. In the event that the roof slope is less than 10 degrees, and the roof is made of bituminous or rolled bitumen-polymer materials, then it is imperative to make a layer of gravel or stone chips to protect the top layer. In this case, the gravel layer should have a thickness of 1-1.5 cm, while stone chips will need 3-5 mm. In the event that the roof is made of metal tiles or corrugated asbestos sheets, then it is imperative to seal the joints between the decks.
5. When calculating the slope of the roof, you need to remember that the amount that you get will depend on the way in which melt and rainwater will be discharged. Water disposal, in turn, can be either external or unorganized, or organized or internal and external.

Advice! It is worth noting that there is no such roofing device that would satisfy all climatic requirements at the same time. Therefore, it is very important to find a middle ground. . Here we must not forget that the consumption of roofing materials increases in direct proportion to the area of ​​\u200b\u200bthe roof, which affects its cost.

After the slope value is calculated, the material necessary for the roof is selected. It should be noted here that piece materials, such as slate and tiles, are used on slopes whose slope exceeds 20 degrees.

In the event that the slope is less, then water will enter the joints, which in a short time can lead to the fact that the roof will become unusable.

Bituminous roll materials are suitable for flat roofs, or for roofs whose slopes do not exceed 30 degrees. This is due to the fact that with a large slope and when exposed to high temperatures, roof sliding can occur.

Such materials can be used on absolutely all types of roofs. For metal tiles and steel sheets required roof pitch no less than 10 degrees.

The roof is considered flat if the slope of the ceiling is not more than 3 degrees. A device of this design does not require a large amount of materials, however, they should be built only if there is a small amount of precipitation.

In addition, the roof and slope device has some varieties:

1. Single roof. Such a roof is represented by an inclined plane, which is fixed on walls of different heights. A shed roof has a simple typical configuration and can be made from any material.
2. Gable roof. This roof has a simple roof structure and reliability.You can cover it with whatever your heart desires. Such a roof consists of two gentle slopes that merge at the top, as well as two slopes that serve as their continuation. With such a roof, you can use the attic space, but it is very difficult to make it. Also, the disadvantage of such a roof is that an impassable attic is formed above the attic.
3. Shaft cover. Such a roof is obtained when several triangles with vertices converge at a certain point. Such a system has an intricate truss structure and a small amount of materials used.
4. Hip roof. It is formed thanks to two triangular and two trapezoidal slopes. Half-hipped roofs have truncated tops located above the end walls. Such roofs are difficult to implement, but economical in terms of consumable material.
5. Vaulted cover. Such an overlap is made in an arc of brick or stone and is currently practically not used, since it has a lot of weight.
6. Multi-gable roofs. They are made in houses with a complex configuration and a large number of junctions and ribs. The advantages of such a roof is that they have a beautiful view and allow you to cover several rooms with one roof, however, it is very difficult to perform such roofs.

As noted earlier: all roof slopes have a suitable material for them. Let's look at the most common types of roofing materials:

1. Tiling. This material is ideal. Roofing from this material has a large number of advantages over other materials. We will not list them all, we will only say that clay tiles have passed the test of time and are still popular. There are many types of this material.
2. Roof panels of factory production. They are completed at the factory and contain everything you need for a modern roof. They consist of a layer of vapor barrier, insulation, a carrier plate and a base. You can mount them at any time of the year without much effort, as they stick together with self-adhesive tape. The disadvantage of this material is the high cost, so this material is inferior to many others.
3. Metal sheets. This item is made from galvanized steel. It is environmentally friendly and corrosion resistant. They can serve for about 75 years, however, they have an outdated appearance.
4. Piece materials from wood, such as shingles, shavings and shingles. Nowadays, these materials are practically not used, since the roof of them is subject to rotting, vermin damage and is easily flammable.
5. Slate. This material is strong, durable, fire and frost resistant and does not let water through. Currently, it can be any color, and not the standard gray, as it used to be.

All types of roofing are laid on a roof slope - the minimum angle of which corresponds to the material used and relies on a structure that transfers the weight of the roof to the building. The supporting structure includes truss trusses and a crate.

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