Press release —
DOYMA Technical Article: The new DIN 18533 – as at June 2026
Thomas Wagner, Sales Manager, Sealing Systems, DOYMA
DIN standards are reviewed by the DIN (German Institute for Standardisation) at least every five years as a matter of routine to ensure that they remain up to date and reflect the current state of the art. Accordingly, an updated version of DIN 18533 was published in June 2026.
DIN 18533 is divided into three parts:
- Part 1 – Requirements, design and construction principles
- Part 2 – Waterproofing with sheet-form waterproofing materials
- Part 3 – Waterproofing with liquid-applied waterproofing materials
The standard applies to waterproofing:
- against ground damp
- against non-pressurised water
- against water exerting pressure from the outside
- against non-pressurised water on slabs covered with earth
- against splash water at the base of walls
- against capillary water in and beneath walls in contact with the ground
Furthermore, the standard may also be applied to underground structures covered with earth, provided these are constructed using the open construction method.
The following amendments have been made:
- The effects of water from the subsoil have been incorporated from DIN 4095-1 and translated into requirements for the waterproofing; the former water exposure classes have been renamed as water stress classes
- Crack and crack-bridging classes have been merged
- Section 9 ‘Door and window connections’ has been revised
- The restriction on the scope of application of polymer bitumen membranes with an aluminium composite reinforcement, type EB, to W.1-E, RN 1-E and RN 2-E has been lifted
- Provisions for the waterproofing of ceiling surfaces in the case of W2-E have been included
- Specifications for waterproofing with FPD have been included
- The documents have been editorially revised. [1]
Effects of water in the ground according to DIN 4095-1
The effects of water in the ground are regulated in DIN 4095-1. [1]
To determine the effects of groundwater on building component surfaces in contact with the ground, a distinction is made between water exposure classes E1 and E2:
- E1: Water exposure due to soil moisture and non-standing water above the design groundwater level
- E2-S: Water exposure due to standing water above the design groundwater level
- E2-G: Water exposure due to groundwater below the design groundwater level [2]
In DIN 18533, water exposure classes for waterproofing are assigned to these effects.
Further amendments to DIN 18533 regarding penetrations
In Part 1, Chapter 10, ‘Waterproofing of Penetrations’, the following sentence has been added:
“When designing the connection between the waterproofing and the penetration in accordance with 10.4, the water exposure to be expected at the location of the penetration shall be the determining factor.” [1]
Furthermore, in the Annex to Part 1, under A.6 ‘Loose and fixed flange constructions’, the sentence:
“The fixed flange must always be positioned on the side facing away from the water.”
has been replaced by:
“The fixed flange shall normally be positioned on the side facing away from the water. However, it may be positioned on the side facing the water if the loose flange is fitted from the inside, e.g. when installing the waterproofing against a wall backing or on the base’s levelling layer, e.g. when sealing a well pot.”[1]
References:
[1] DIN 18533-1:2026-06, Waterproofing of building elements in contact with the ground – Part 1: Requirements, design and construction principles
[2] DIN 4095-1: 2026-06, Building sites – Effects of water on structures in contact with the ground and drainage for the protection of structures – Part 1: Definitions and effects of water
