Information about coefficient of friction
Video about coefficient of friction
Watch the video to learn how to determine the coefficient of friction step by step on a flat roof and integrate it into the Base On planning software.
The value of coefficient of friction
The structural integrity of a penetration-free mounting system is achieved by the dead weight, module weight and additional ballast. Prerequisites for a proper assembly include suitable roof construction, as well as sufficient loadbearing reserves of the building.
A significance influence on the structural integrity of this type of construction is the interaction between roof covering and the building protection mat, and between mounting system and building protection mat, which are defined by the coefficient of friction. The coefficient of friction is incorporated in the static calculation 1:1. It is therefore necessary to determine the friction coefficients on site and verify them.
The coefficient of friction, also called friction values (formula symbol μ), is a dimensionless measure of the frictional force in relation to the pressure force between two objects.
Coefficient of friction µ = F : G
Testing coefficient of friction
For testing, you need the coefficient of friction case, which you can purchase from K2. This tool can be used to determine the value on bitumen, foil, concrete, gravel and green roofs.
Step by step testing:
- Prepare the roof surface for subsequent assembly and if necessary clean with water
- Place the test weight on the roof surface and leave for 10 seconds
- Pull the spring tension balance at a right angle to the roof pitch
- Read the weight as soon as the test weight starts to slide
- Measure on dry and wet roof surfaces at several locations
- Measure the high and low points, the corner, edge and center area of the surface.
Input in Base On
Please enter the determined value in the "Roof" area in Base On. Please pay attention to the notes on page 4 in the coefficients of friction protocol.