Nearly every driveway failure we are asked to look at is a water problem wearing a different hat. Rutting, edge spread, moss, sunken blocks and water under a garage door all trace back to a surface built without a plan for rainfall.
Sustainable drainage, usually shortened to SuDS, simply means dealing with water where it falls instead of pushing it into a drain or a road. On a driveway it is neither complicated nor especially expensive, provided it is designed before the excavation depth is set.
The three ways to deal with driveway water
- Permeable surface over an open graded base, so water soaks through the drive itself
- Falls to a linear channel drain, then to a correctly sized soakaway on your land
- Falls to a planted border or lawn wide enough to absorb the run off
Getting falls right
A driveway should always fall away from the house, not towards it, and the fall needs to be consistent enough to move water without being noticeable underfoot. Around one in eighty is a sensible working figure.
The critical detail is the threshold. A garage or door threshold needs a channel drain across it, set slightly below the finished surface, because that is the line where water enters buildings.
Soakaways, sized rather than guessed
A soakaway has to be sized against the area draining into it and the infiltration rate of your ground. On the clay across much of north Essex, a modest crate soakaway will fill and stop working, which is why we sometimes recommend land drainage or attenuation instead.
Position matters too. A soakaway must sit at least five metres from a building and clear of foundations, so it belongs on the drawing rather than being fitted in at the end.
What we specify as standard
- Falls surveyed and set before excavation depth is fixed
- Geotextile membrane between subsoil and sub base where required
- Open graded stone where a permeable build up is used
- Channel drainage at every threshold and garage line
- Soakaway or attenuation sized to the contributing area
- Nothing discharging onto the pavement or road
Services this relates to
Want the figure for your own property? Call 07770 880587 or email enquiries@breakinggroundltd.com and we will arrange a site visit.