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Roof pitch calculator

See also: Gable roof calculator, Gambrel roof calculator

Drawing scale:

Enter parameters in mm:

Height, Y mm
Width, X mm
Overhang distance, C mm
Length, B mm

Roof construction materials:
(fill in 0 if no need)

Rafter width, S1 mm
Rafter thickness, S2 mm
Rafters spacing, C3 mm
Roofing verge distance , C4 mm
Roof boarding width, O1 mm
Roof boarding thickness, O2 mm
Roof boarding spacing, R mm
Roofing sheet(or tile) height, L1 mm
Roofing sheet(or tile) width, L2 mm
Sheet overlap percentage L3

Roof pitch draft and construction


This online roof pitch calculator can assist you in calculating the amount of the construction materials needed to build a single sloping surface type of a housetop, in particular, you are able to estimate the required quantity of the sheeting material (metal tile, asbestos slate, metal slate etc.), sarking boards for sheathing and rafters for trusses, underlay material (rubberoid or asphaltic felt, asphalt paper).

Note, that the estimator calculates the needed quantity of materials based on the total area value. If you want to get the exact number of sheets, you have to decrease the height of them until you get the round figure of rows number.

The programme calculates approximate price and costs by realizing an approximate amount of roofing materials for the construction. It is recommended to buy construction materials with an additional stock leaving some for possible waste and defects. The figures you get are only preliminary, because prices can be slight different in real.

The shed roof (roofing) calculator estimates:

  • length of a rafter needed to construct a truss (it is calculates as distance from the base of a building (the span) to the ridge);
  • quantity of rafters having taken into account a set pace;
  • dimensions of a rafter (when calculating the parameters concerning rafters the future load will be considered due to the selected dimensions);
  • required boarding (sheathing) (the app estimates an optimal distance for the boarding when construction materials are used without cutting);
  • number of sarking boards rows;
  • square area to be covered, it includes the length of a slope;
  • truss design in line with the drawings and estimated possible pressure to carry;
  • amount of pitch roofing material (tile, metal, slate, etc);
  • amount of underlay and insulating material if applicable;
  • other parameters based on the data entered.

This type of a housetop is the simplest structure of the covering when you compare it with others. It has only one slope, unsophisticated design of a framework and requires a limited amount of construction materials. Because of that, it is the most common solution used to cover the household buildings, support structures, garages, small houses, hangars, barns, warehouses and other non-residential premises. Buildings can be with and without a garret. It can be faced or covered by any materials with insulating and sub-roof materials. As a rule, the slope angle is narrow. Regardless the simplicity, you must remember about the pressure caused by snow and throw it off on time.

How to calculate roof pitch?

It is set on walls of a building, which are of different height. Thus, angles of a slope between the base level of a building and rafters should be within the range from 5° to 60°. The angle must correspond with the covering material you have chosen for the facing. According to the recommendations given further, you may change the height of rise and the width of a building to increase or decrease the angle.

The slope angle depends on such parameters as a type of covering material, precipitations amount, and wind strength in your region. The properly selected material ensured necessary technical properties. Various materials have different recommended angle of a slope to withstand the load, which may occur in winter season. You should not neglect the reference data, otherwise the covering may bend or deform.

Note that pent and pitch roofs are same things. So all recommendations can be applied in both cases, same as the necessary calculations could be done.

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