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Flood Risk Assessment - Flood Resilient Design

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Material Water Penetration Drying Ability Retention of pre-flood dimensions
Bricks      
Engineering bricks (Classes A and B) Good Good Good
Facing bricks (pressed) Medium Medium Good
Facing bricks (handmade) Poor Poor Poor
Blocks      
Concrete (3.5N, 7N) Poor Medium Good
Aircrete Medium Poor Good
Timber board      
OSB2, 11mm thick Medium Poor Poor
OSB3, 18mm thick Medium Poor Poor
Gypsum plasterboard      
Gypsum Plasterboard, 9mm thick Poor Poor Poor
Mortars      
Below d. p.c. 1:3(cement:sand) Good Good Good
Above d. p.c. 1:6(cement:sand) Good Good Good

General advice for resilient design

Where concrete ground floor slabs are used, the blockwork substructure is often the weakest point in terms of water penetration from the ground into a dwelling. Whereas there is a general perception that water can ingress through the blockwork structure of the external face of a wall into the property, it is less apparent, but equally possible, that water will penetrate from the ground on the inside of the pro perty. Figures 6.2 and 6.3 illustrate these flow paths for two types of ground floor (ground bearing floor and suspended concrete floor), and different types of foundation (typical for construction in England).  Concrete blocks used in foundations should be sealed with an impermeable material or encased in concrete to prevent water movement from the ground to the wall construction.

Please feel free to contact the office for an informal discussion regarding your requirements.

Read more on:

Flood Resilient Design - Flood Resistant Design - Temporary Refuges - Surface Water Management