Flat roofs

When followed principles it is almost impossible an accident with regards to usage of mecahnical anchoring.

Nowadays there are on the market many anchoring components, despite of their quality not usually suitable. Anchoring components are used mostly these made from plastic and metal material. Anchoring component needs to guarantee tensile strength, deformability and corrosion resistance. That is recommended at least 15 Kesternich cycles (cold galvanized screws have corrosion resistance to 2 and zinc-coated to 8 Kesternich cycles.
Especially in reconstructions of old roofs is the anchoring component exposured by abnormal moisture and sometimes it is recommended components from stainless steel to be used. As you might know, commonly produced screws and nails are for mechanical anchoring completely unsuitable. Also unsuitable would be to use anchoring components that for usage on exterior siding. Keep in mind that the anchoring components are strained except moisture of roof covering moisture also by dynamical wind straining (suction). Therefore it is important to choose anchoring component that is designed right for the required material.

The anchoring to base from trapezial metal, concrete of various quality and wood are most commonly used.

Trapezial metal:
For anchoring of needed roofing structure we are using either corrosion resistant or self-drilling screws in connection with joggles (creates telescope and breaks the thermal bridge) or with thrust washer. With aggressive action on roof covering (mostly for food, chemical and metallurgical industry, swimming polls and winter stadium) or on aluminium plates are metal components used with minimal corrosion resistance of 30 Kesternich cycles or from special stainless steel.
Length of metal component is given by thickness of structure plus 20mm. This ensures holding the effective part of screw in metal. Here is important to respect on-stepping of anchored component and head of screw or steel washer can't perforate anchorage isolation. Hence are nowadays mostly used anchored components in conjunction with joggle and screw. In the course of construction is very important to know thickness of trapezial plate and anchoring isolation and essentially anchored in the upper wave of metal.

Wooden valve:
Today the hydro-isolation is anchored mostly to valve made from laths, plywood or from various boards (e.g. OSB). By reason of nonacquaintance of mechanical anchoring and its influence on the structure of the roof covering (wood desiccation, dynamic strength etc.), here most of the companies are aimed to use the classical anchoring by nails, which is an ideal solution when accident occurred. Roofs from wood valves shouldn't let us be carelessness as they involve the same preparation attendance as concrete roofs.
Anyhow it is necessary to consider the environment where the roof is installed and the wood quality. It is recommended to submit a tensile test and use only those screws that are right for this technology of roof (corrosion resistance and construction of bolt thread). It is well known that screws with low corrosion resistance in wood have very short lifetime. In case that only hydro-isolation sheet is anchored corrosive modified screws and washers are usually used. If roof construction contains also thermo-isolation, we will use screw and either washer or disc joggle for connecting.

Concrete:
Concrete as an underlay component, because of its heterogeneous character, belongs to quite fastidious components regarding all the rules of anchoring and technological discipline. It is recommended to submit deep revision of roof covering and tensile strength. In case of older roofs there is aware that during the realisation might appear some spots where the outlined anchored component would not be functional. We, therefore, recommend that you immediately contact the supplier of anchoring components to solve the situation altogether.
According to the need there is also used either anticorrosive thrust washer or plastic joggle together with anchoring component that is selected according to the quality of concrete. Its length is derived from the thickness of the anchored material, quality of the underlay and the result of the tensile test. Into prefabricated panels or concrete of very good quality the anchoring component as stainless nails or special screws (that are designed for anchoring component into concrete) are used. Here a hole is usually drilled whose perimeter is determined by the supplier of the anchoring component.
For anchoring into thin-walled prefabricated panels it is recommended to use equipment with pneumatic damping of shocks to avoid dropping out of concrete when working on soffit of the roof. Besides each drilling into concrete needs to keep in mind that pressure should not be applied on drill and that drilling through old tar paper and isolation causes over-warming of the drill.
For concretes of lower quality or expanded concrete as anchoring components are usually used special screws designed for this underlay, or plastic washers with arbor, or washer, screw and joggle. Also in this case is important to keep in mind that concrete contains high percentage of moisture, therefore, it is needed to use again corrosion resistant anchored components.

Other materials: Except of common roof underlayers, we may come across another materials to which is necessary to mechanically anchor the roof structure. In this case it is recommended to consult it with anchoring components supplier and submit a tensile test that prove and determine feasibility of mechanical anchorage.