The Importance Of Surface & Sub Surface Drainage


Drainage is so important and more often than not is overlooked or not completed properly. The benefits from installing the correct drainage system are very high, ranging from financial to your own health.    

Many house's renovations and extensions involve excavating into a slope, where slab on ground/retaining walls are installed below the outside ground level. Wether in rock or soil, the correct system should be sufficiently installed at correct depths that are able to fall to outlets away from the house. The most common error is the depth of the drain. For instance, AG lines are a great way to channel water away from your house but remember, in seepage terms, water can pass out from an AG line as quickly as it gets in. This will leave the soil wet or, if just laid on top of rock, makes for no impact at all. 

Every retaining wall must have a drain behind it and the drain must be below the floor level and able to fall to outlets, otherwise a pump system can be used if the fall can't be maintained e.g. in basements. Structural issues arise because water cannot get away and lays there for a number of years subsequently eroding the soil underneath the foundations. Movement in walls then occur, leaving cracks in walls and slabs and remedial repairs are needed, usually at a high cost. 

Water damage is another issue where water passes through an incorrect system and causes flooding and damage internally to floors, cupboards and carpets. Health problems can also be caused by stagnant water and inadequate ventilation. This usually happens through seepage which makes damp soil and rock in sub floors build up moisture, resulting in damp walls, floors and air, as well as mould in cupboards and walls.

Surface drainage can help reduce the impact of bad subsurface drainage by catching the run off from paths and driveways and directing it away from the house. Correct positioning of grates and pits can eliminate a lot of water penetration below the surface. 

There are many different ways this can occur but some things you can check yourself at home are:

  • Garden beds next to walls - this is never a good idea as it's a catchment point for rain. 
  • Blocked storm pipes 
  • Old clay pipes - these are often a cause of water seepage because of roots breaking through. 
  • Outside levels - are they too high above a damp coarse?
  • Inadequate ventilation - good ventilation can eliminate odours if used in conjunction with a good drainage system.  

We offer services that can solve the problem of water seepage and provide a tried and trusted approach to solve every problem, residential or commercial. If you'd like us to help you, feel free to contact us today!