Building drainage keeps the area under buildings dry. It preserves the value of the building fabric and provides a healthy living environment. Building drainage is more than just a recommendation for all buildings.
Sub-surface drainage is used to remove underground water, most of the time by using perforated or slit pipes. Building drainage generally refers to all necessary means for drainage that are used to protect buildings against damage from humidity or moisture from the surrounding soil.
Building drainage is of great economic importance! 90% of all structural damage to basement areas can be prevented by proper drainage. Hence, it significantly helps to preserve the value of a building. Building drainage turns basements into living space for sports, leisure and recreation, because it keeps walls dry. Damp basements are also the perfect breeding ground for mold, which proves to be highly detrimental to health. Building drainage is therefore also important to a healthy living environment.
Building components that have immediate contact with soil, such as foundation slabs or basements, frequently come in contact with different types of water – ground water, seepage water, strata water, etc. If water dams up, this can damage the house. Building drainage (ring drainage) in combination with a proper impervious blanket of the basement wall protects basements against humidity. The dammed-up water will be safely drained, moisture will not penetrate the basement. Basically, drainage should be included in every building although this might seem unnecessary due to dry building pits.
Standards and Guidelines
DIN 4095 is the most important standard for building drainage and describes drainage to protect structures during planning, dimensioning and construction.
DIN 4095 "Planning, design and installation of drainage systems protecting structures against water in the ground" ( „Dränung zum Schutz baulicher Anlagen – Planung, Bemessung und Ausführung")
The standard applies to drainage on top of, next to and under physical structures that come in contact with soil. DIN 4095 describes the components and criteria of proper drainage systems in underground engineering and is in particular connected with the measures of waterproofing according to DIN 18195. DIN 4095 defines the state of the art and must generally be fully considered from planning to installation of a drainage system! It clearly demands reliability, verifiability and durability of drainage systems. It demands verifiably performance criteria and the certified suitability of materials. Insofar as applicable DIN regulations and quality guidelines are available, materials must comply with them.