Lift Pit Tanking

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Waterproofing a lift pit

Damptec Systems Ltd supply and install tanking systems for lift pits.  Our waterproofing systems are installed in accordance with BS 8102 2022 Protection of Structures Against Water from the Grounds.  They are designed to satisfy requirements for a “Grade 3” environment where no dampness is permitted and where the internal environment needs to be managed using appropriate environmental controls.

A typical tanking system would incorporate:

  • Type A: Barrier Protection – external waterproofing
  • Type A: Barrier Protection – internal waterproofing

A lift pit screed must be of sufficient depth so that any fixings do not penetrate beyond it and into the tanking slurry we apply.


During Damptec’s first visit to the lift pit, we apply Delta Dual Proof over the sub site.

The main contractor then casts the main concrete slab. It is then over to the builders to erect blockwork up to ground floor level incorporating land drains away from the property.  

Damptec then returns to site to install the following:

  1. Form a 50mm fillet along the foundation toe using Koster Repair Mortar. This helps shed water away from the structure.
  • Apply 2 coats of Delta Deuxan 2C Water Proofing Solution over external face from ground level down to the land drain.
  • Apply Koster Glass Fibre Mesh between coats.
  • Apply Delta Geo Drain Quattro fixings over the top of the Deuxan.

WATERPROOFING TYPE “A” (Internal Barrier Protection)

Treatment to internal walls and floor.

  1. All concrete dressed with anti-lime coatings. We always treat new concrete and new substrate. This method will decrease the danger of the new development of salt efflorescence and free lime egress, and raises the resistance of mineral substrates to freezing and thawing.   
  1. Form a fillet along the wall and floor junctions using Koster Repair Mortar.

Apply two coats of Koster NB1 Grey Cement Based Waterproofing Slurry. This is a mineral waterproof coating that contains crystallising and capillary-plugging agents. When these penetrate into the substrate, they develop an intense bond and the capillaries are plugged making it completely waterproof to pressurised water of up to 13 bar.  

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