FAQ.

Yes, that is possible. The last pages of the Sita price list contain a list of frequently re-ordered components. 
 

According to DIN 1986-100, point 14.2.4.1, the planner must check whether wind-driven rain on façades has an influence on the rainwater discharge and must therefore be added to the roof surface area relevant for discharge. 

According to the point 1.3.12 of the drainage planning data sheet of the Flat Roof Guideline (Merkblatt zur Bemessung von Entwässerungen der Flachdachrichtlinie), larger façade areas of 3 m or more should be considered at 50%.

The more information, the better. But we only need details of the roof, roof plan, slope plan, insulation height at the low point, location of the property, ballast, contact details, etc.

No, unfortunately it isn't possible to say, because too many factors have to be taken into account in the calculation. Since March 2002, with part 100 of DIN 1986, for example, location-specific rainfalls must be assumed when dimensioning flat roof drainage, so that theoretically larger areas can be drained with an outlet in the north than in the south of Germany. An important influencing factor is also the static reserves of the roof construction and also whether the roof is planned with or without ballast. 
 

According to DIN 1986-100, one outlet and one emergency drainage system must be provided for each roof low point, or it must be possible for water to flow from each roof outlet to an emergency drainage system that is capable of draining at least the difference between the hundred-year rainfall and the design rainfall. Emergency drainage can only be dispensed with in the case of solid ceilings where a flood and overload analysis has been carried out.

Even in that case, however, it must be demonstrated that in the event of backflow on the roof surface, the roof's structural characteristics are not exceeded and that the waterproofing membrane is routed high enough so that water cannot penetrate anywhere and damage the building. Sita recommends always providing emergency drainage, e.g. to have an overflow if the main drainage is blocked, so that the roof does not completely fill up.

The products must not be directly set in concrete because of different rates of linear expansion, structure-borne noise transmission and condensation. Before they are set in concrete, the products must be protected with a jacket, e.g. Insulation roll.
 

According to DIN 1986-100, point 5.3.1, rainwater does not necessarily have to discharge via the drainage system, but may also discharge by other means in individual cases if the building is protected against moisture penetration and the rainwater can run off or seep away unhindered and without affecting third parties.

Unfortunately, Sita Bauelemente does not have any figures with which to compare the noise generated by the two systems. In order to minimise the sound transmission of a drainage system, it is necessary to decouple it from the building using suitable fastening technology.  

The SitaPipe PP pipe is only suitable for conventional drainage. For siphonic drainage systems (the SitaDSS systems), Sita offers pipes and fittings made of polyethylene (PEHD) as well as the SitaPipe Edelstahl pipe system.

To ensure that at least 20 mm of insulation can be laid under the pipe, approx. 120 mm is required. With the 20 mm of WLG 040 insulation, an analysis of the physics shows that the temperature is not expected to fall below the dew point under standard conditions.

"Yes. Condensation is the water that collects on a cool surface as soon as air containing water vapour cools below the dew point.
The pipe wall can cool down through the connection to the outside air to such an extent that the water vapour condenses in the roofing layers. "
The installation of dry thermal insulation and the careful laying/bonding of necessary vapour barriers minimise the formation of condensation in the roofing layers. Condensation on the inside of the heated space below can be prevented, for example by providing sufficient insulating material thickness below the SitaKaskade Inside.  
 

According to the recognised rules of technology, it is not possible to drain a balcony with an accessible threshold using only drainage components. Additional measures are always required involving the waterproofing membrane, the slope and also the balcony door in order to design this special construction.

The need for emergency drainage is not determined by the ballast. In the case of green roofs on concrete slabs, emergency drainage could be dispensed with. In the case of lightweight roof structures, emergency drainage must always be provided, DIN 1986-100, point 5.8.2.2.

The term retention means holding back the rain. For flat roofs, retention means that rainwater is held back with ballast for example, such as gravel, extensive and intensive greenery. Sita uses the term retention for outlets which are restricted in order to comply with discharge restrictions.

To properly refurbish a siphonic drainage outlet, a functional part must be installed in the outlet that prevents air from entering the system, e.g. SitaAirstop. It is also necessary that the backflow seal between the outlet and the extension unit remains stable and permanently watertight, even when there are movements in the roof or when the outlet and the connected pipe are fully filled.

The SitaSani 160 DSS with Airstop is therefore only suitable for existing siphonic drainage outlets with a pot diameter of 160 mm. Sita cannot confirm the functionality of larger pot diameters.

Yes, according to DIN 1986-100, point 5.8.4, the discharge capacity of the existing drainage system must be checked during refurbishment. The system must also be checked to verify that emergency drainage systems are present, sufficiently dimensioned and correctly arranged.

The pressure loss curve shows the air change rate in m³/h at a particular pressure when the SitaVent system vent is used either with a protective grating or with a rain cover. This information can be used to select a mechanical ventilation system, e.g. for interior bathrooms.

To the pressure loss characteristic

Yes, the SitaVent Fireguard is suitable for industrial halls with trapezoidal sheet metal roofs that must meet the fire protection requirements according to DIN 18234 or the Industrial Building Guideline (Industriebaurichtlinie).

The Sita solutions for F-requirements are presented in an expert opinion. This contains an installation example with the SitaVent system vent. See link to the expert option and link to SitaTipp 009.

The expert opinion refers to the Model Piping System Guideline (Muster-Leitungsanlagenrichtlinie), which permits components made of non-combustible materials in F90 ceilings. This means that the SitaKaskade lead-through Fluid could also be used as a pipe lead-through. This is because it is made entirely of stainless steel.

Sita cannot recommend the use of the SitaFireguard series in concrete roofs, as these components have only been tested and developed in accordance with the requirements of DIN 18234 in trapezoidal steel roofs.

Yes, the SitaPipe PP pipe is suitable for building heights of up to 15 m, as the pipe and the connections are approved for an overpressure of up to 1.5 bar.

There are relevant assembly and installation instructions for the SitaPipe pipe systems and also for the SitaDSS pipe system, containing information such as fixing distances.

Assembly instructions SitaPipe stainless

Installation instructions SitaPipe PP