DIN 18560

Area	Construction
title	Screed
Brief description:	Screeds in construction
Latest edition	2003-2015
ISO

The DIN standard DIN 18560 "Screeds in construction" describes the types, execution and requirements for screed . It was last revised in September 2009 (affects parts 1 and 2) and, together with DIN EN 13813, replaces the version from May 1992.

Part 1: General requirements, testing and execution

Part 1 sets requirements for thickness, dry bulk density, fire behavior, thermal insulation, sound insulation and outdoor screeds. The testing of screeds is also described. Here, between the incoming inspection (checking the conformity of the product information with the order), the hardening test (information on usability at a certain point in time, testing only in exceptional cases) and the confirmation test (taking samples if there are doubts about the quality of the installed screed, testing only in Special case). In addition, the execution of the most common types of screed ( calcium sulphate screed , mastic asphalt screed , magnesia screed, synthetic resin screed, cement screed) is regulated by standards.

Part 2: Screeds and heated screeds on insulating layers (floating screeds)

Heated screeds are divided into three design variants:

Systems with pipes within the screed
Systems with pipes below the screed
Systems with pipes in the leveling screed, on which the screed is applied with a two-layer separating layer

The maximum heating temperatures for heated screeds are also regulated:

Screed type	Hot water underfloor heating	Electric underfloor heating
Mastic asphalt screed	45 ° C	55 ° C
Calcium sulphate screed	55 ° C	65 ° C
Cement screed	55 ° C	65 ° C

The minimum nominal thickness * is also regulated depending on the hardness class (EN 13813) (for vertical payloads ≤ 2 kN / m²):

Screed type	Flexural strength or hardness class	Minimum nominal thickness in mm
Calcium sulphate floor screed	F4 F5 F7	35 35 35
Calcium sulphate screed	F4 F5 F7	45 40 35
Mastic asphalt screed	IC10	25th
Synthetic resin screed	F7 F10	35 30
Magnesia screed	F4 F5 F7	45 40 35
Cement screed	F4 F5	45 40

(* For higher useful and surface loads, correspondingly higher minimum nominal thicknesses apply)

Statements are made about the minimum nominal thickness of heated screeds (here: for systems with pipes within the screed).

Calcium sulphate and cement screed:

Minimum nominal thickness = minimum nominal thickness depending on the payload + heating pipe diameter

The minimum pipe overlap is 45 mm for flexural strength class F4. For higher flexural strength classes, a minimum coverage of 30 mm is permissible.

Mastic asphalt screed:

Payload ≦ 2 kN / m²: minimum nominal thickness = 35 mm

Payload ≧ 2 kN / m² and ≦ 5 kN / m²: minimum nominal thickness = 40 mm

The minimum pipe overlap is 15 mm. Only mastic asphalt screeds of hardness class IC10 are permitted

Furthermore, the nature of the insulation layer and the subsurface, the installation and testing of component thicknesses that deviate from the standard are regulated.

Part 3: bonded screeds

With composite screed constructions, the screed forms a force-fit connection with the sub-floor. In order to ensure a sufficient bond between the screed and the substrate, it should be noted that not all types of screed should be installed on all substrates.

Suitability of various substrates for bonded screeds:

Underground	concrete	Calcium sulphate screed	Magnesia screed	Cement screed	Mastic asphalt screed	Wood	steel
Screed type
Calcium sulphate screed	+	+	O	+	O	O	O
Mastic asphalt screed	O	-	-	O	+	O	O
Synthetic resin screed	+	O	O	+	O	O	O
Magnesia screed	+	O	+	+	O	+	O
Cement screed	+	O	-	+	O	O	O

(Explanation of symbols: + suitable; o suitable with special measures; - not suitable)

According to DIN 18560-3, the nominal thickness of composite screeds should not exceed 50 mm for calcium sulphate, synthetic resin, magnesia and cement screeds and 40 mm for mastic asphalt screeds.

In order to ensure a positive connection, the surface must be free of all types of contamination (oil, fuel, mortar residues, etc.). DIN 18560-3 also regulates the testing of bonded screeds, which should be carried out in exceptional cases (doubts about the quality of the screed).

Part 4: Screeds on a separation layer

Screeds on a separating layer are not positively connected to the load-bearing substrate.

The minimum nominal thickness of screeds on a separating layer should not fall below the following values:

Screed type	Minimum nominal thickness in mm
Calcium sulphate screed	30th
Mastic asphalt screed	25th
Synthetic resin screed	15th
Magnesia screed	30th
Cement screed	45

The load-bearing substrate must meet the static requirements and have a flat (flatness tolerances according to DIN 18202), burr-free surface.

Furthermore, the testing of screeds on the separating layer, which should be carried out in exceptional cases (doubts about the quality of the screed), is regulated by norms.

Part 7: Heavy-duty screeds (industrial screeds)

Part 7 applies to directly used (i.e. no other flooring) calcium sulfate, mastic asphalt, magnesia and cement-bound hard aggregate screeds.

Three mechanical stress groups are defined. :

Stress group	Type of tires on the truck	Examples: work processes, pedestrian traffic
I (difficult)	Steel, polyamide	Processing, grinding and rolling of metal parts, depositing goods with metal forks, pedestrian traffic with more than 1000 people / day
II (medium)	Urethane , vulkollan , rubber	Sanding and rumbling of wood, paper rolls and plastic parts. Pedestrian traffic of 100 to 1000 people / day
III (easy)	tire	Assembly on tables, pedestrian traffic up to 100 people / day

Highly stressed mastic asphalt screeds are to be executed as screeds on a separating layer, from a nominal thickness of 40 mm as a multi-layer construction.

The following minimum nominal thicknesses are specified for such screeds, depending on the largest grain size of the aggregate:

Stress class	Minimum nominal thickness in mm	Largest grain of the aggregate in mm
I (difficult)	35 30	11 8
II (medium)	30 25	8 5
III (easy)	30 25	8 5

Highly stressed synthetic resin and magnesia screeds are generally to be executed as bonded screeds.

Furthermore, the test is described in special cases as described in parts 3 and 4.