Basement WaterproofingCementitious Basement Waterproofing – New or Refurbishing

New Construction

Designing Cementitious Basement Waterproofing of a building starts at the basement and finishes at the roof of the building.

The initial waterproofing of a basement is a crucial part of waterproofing preventing water penetration of the wall structure. Like waterproofing lift wells or pits they are an integral part of a building whether it’s for an livable area or a basement carpark. The consequence of a waterproofing failure of the basement will cause damage to the structure:

  • of the wall weaking the walls & reducing longevity of the structure, even collapse of the wall over time.
  • causing the rusting of the steel re-reinforcement – which can increase up to 8 times it’s original size
  • mold & fungus inside the basement & resultant health issues
  • higher maintenance costs
  • timing of the application

The use of Aggie pipes in many cases is moot. There is often not enough room to place the aggie pipe in a suitable location and the Aggie pipe works by draining water away from the structure. This assumes the pipe drains some where and continues to drain water away from the wall for the life of the structure. Complexity of such a system which will not to clog, wash soil away from footing and the like is difficult at best & seems to perhaps be an expensive sand filter at best.

Cementitious Waterproofing Membranes are ideal in the new construction as they are in a renovation waterproofing job. The reason the team believe the are best below grade (ground Level) is since if you use adhesive based sheet membranes or liquid based membranes is that they usually require completely dry concrete surfaces, very difficult, a pin hole will cause delamination of the membrane over time. Damage caused by the trades in the construction process, drilling through the wall, for pipes, electrical all causing possible breaches which may to hard to seal around after the original membrane is installed, cause undetected pin holes left unsealed allowing water entry points from the start and total delamination in the future.

Cementitious waterproofing membranes like Drizoro Products Drizoro Maxseal Flex | Drizoro Maxseal Foundation | Drizoro Maxseal | Drizoro Maxjoint Elastic adhere to the cement or concrete surface & become part of the original surface and will not be pushed off  if the application correctly applied. Pin holes would be self healing and prtrusions created by the trades can be sealed around by putting a coving around them with Drizoro Maxrest and then sealing around it with Drizoro Maxseal Flex.

Waterproofing Structures on the exterior or positive side of the Basement Wall

Drizoro Products required:

  1. Prepare area to be treated by removing any loose materials any efflorescence ensuring the surface is clean and sound surface.
  2. Any damage to the surface should be repaired using Drizoro Maxrest.
  3. Any missing mortar can be replaced with either Drizoro Maxrest or Drizoro Maxplug
  4. Apply Two coats Drizoro Maxseal Flex X 150mm cover over footing & wall joint incorporating Drizoro Maxmesh into the first coat
  5. Allow 14 hours minimum between coats.
  6. Two coats of Drizoro Maxseal Foundation | Drizoro Maxseal  can be applied to all other rigid surface are as of the wall, 50mm overlap onto the cured Drizoro Maxseal Flex
  7. Leave 4 to 7 days before back filling if required
  8. If rain is expected within 5 hrs do not apply. If a backfilling time is an issue, It is suggested that the coating be a applied as the wall is being constructed.
  9. Do not place plastic membrane or the like after coating.
  10. Any external penetrations require Drizoro Maxplug and a coating of Drizoro Maxseal Flex incorporating Drizoro Maxmesh

Interior Cementitious Basement Waterproofing

The refurbishment of external basement waterproofing is difficult, if not impossible, and the cost is usually enormous. Excavation, making the excavation safe.

Basement Waterproofing-internal-ingress-seepageThe need for using an interior repair to a basement wall is usually self evident by the presence of :

  • a persistent musty smell
  • dampness in the wall
  • effervescence
  • changes in the water table may cause seepage of leaking

Before attempting expensive repairs a check to see if it’s just condensation on the wall rectified simply by dehumidifying the basement area. Not having the correct run off away from the walls may be a problem in high rain fall areas.

No matter what causes the problem of a damp basement to prevent worse problems the best way to fix it is to seal the wall completely using Drizoro Products Drizoro Maxseal Flex | Drizoro Maxseal Foundation | Drizoro Maxseal | Drizoro Maxjoint Elastic which can seal even high hydrostatic water pressure. Often  it is recommended to use sump pumps but according to David Cook’s

“This is a very common yet misguided solution that is used all over the country. The idea behind fitting a sump pump is born out of ignorance, the “you can’t stop it, pump it out” mentality is steeped in danger!”

In the first instance you need to break into a reinforced concrete base that has been specifically designed to take the loading of the ………….buildings walls …and possibly other areas of the building. This raft WILL NOT have been designed for someone to come along and cut a hole into the concrete which will invariably involve exposing the steel reinforcing or worse cutting through it.”

Specifications for Cementitious Waterproofing of Basements with Hydrostatic Pressure

Basements, Retaining Walls and Tunnels to prevent ingress of water due to hydrostatic pressure.

Drizoro Products required:

Drizoro MaxrestDrizoro Maxseal Flex | Drizoro Maxseal Foundation | Drizoro Maxseal | Drizoro Maxjoint Elastic | Drizoro Maxmesh | Drizoro Maxplug
waterproofing-detail-basement-wall-cementitious-membrane-internal-negative-pressure

Method

  1. If water is flowing on the surface of the wall then it may be necessary to drill holes or chisel loose mortar lines especially at the base of the wall to allow water to drain from the face of the wall surface.
  2. If rendered remove all render and paint.
  3. At the  floor-wall joint chisel maxplug-squarecut-reverse-cork-stops leaks-intantlyopen floor-wall joint to prepare for a coving. (All cracks & joints should have a minimum depth of 2 centimetres and an opening of 1.5 to 2 centimetres. Make a square-shaped cut, preferably dovetail to the surface to which the material is to be applied; avoid the “V” shape)
  4. Prepare area to be treated by removing all loose materials and efflorescence  ensuring a clean and sound surface. (Note:-efflorescence my grow back in a 24hour period if necessary the use of Efflorescence Rid is recommended)
  5. Apply a single coat of Drizoro Maxseal Foundation at the prescribed rate to the entire wall including cracks, mortar lines, floor slab wall joint. (Note:- NO water flowing on the wall face – may still be flowing from floor-wall joint or any drilled holes)
  6. Allow overnite curing of the first coat of Drizoro Maxseal Foundation. Where ever there no water flow from prepared holes & cracks fill these with Drizoro Maxrest. Where water is flow is present use Drizoro Maxplug to halt the water flow (use as per technical bulletin)
  7. To the coving at the floor slab wall intersection apply to damp surface 150mm vertically from joint using Drizoro Maxseal Flex and return to slab 150mm incorporating Drizoro Maxmesh into the initial coat (this method to be used for all cold, construction and dummy joints)
  8. If pinholes of water are visible after 14 hours after the first coat, drill and plug area with Drizoro Maxplug until area is dry
  9. Apply second coat of Drizoro Maxseal Flex to the joints
  10. Apply  second coat of Drizoro Maxseal Foundation or Drizoro Maxseal onto the remaining rigid damp wall (or damp surface as necessary) surface area of wall overlapping Drizoro Maxseal Flex by 50mm. If further leakages are notable repeat procedure at point 4 above
  11.  Minimum of 14 hours before rendering, 7 days before painting
  12.  If the surface area has a low porosity value Drizoro Maxseal Flex should be used in place of Drizoro Maxseal Foundation or Drizoro Maxseal
  13.  If excessive amounts of salt are prevalent on the structure do not use Drizoro Maxseal Foundation or Drizoro Maxseal in these areas.  Please refer to efflorescence specifications treating-efflorescence-salts-for-adhesion.pdf
  14.  Use this information in conjunction with the appropriate technical data bulletins.
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