Waterproofing of External Basement Walls using Koster Deuxan 2C - Robust underground waterproofing system.

Required.

Guidance for specification option:

All application surfaces are to be fully cleaned, ideally using a high-pressure waterjet, to remove any shuttering release oils, mud and other contaminates. This should also remove any weak concrete from the surface. Use Koster Repair Mortars to repair any honeycombing or areas of damage as well as for ensuring the surface profile is smooth and even. Check carefully for any cracks or other defects.

All external junctions to be mechanically ground to remove sharp edges and ensure an even application for the system.

Koster repair mortar plus.

Guidance for specification option:

• This is a fast setting and expanding repair mortar. 
• It is used for making strong and watertight repairs to the substrate, prior to the application of Koster waterproofing systems, and for forming fillets at internal junctions. 
• For instance, a 40mm x 40mm concave fillet should be made at all wall to wall and wall to slab intersections. 

Koster bitumen primer.

Guidance for specification option:

• For use when preparing to waterproof over old or existing bituminous coatings.

Koster polysil TG 500.

Guidance for specification option:

• Deeply penetrating primer.
• When sprayed onto the prepared wall surface, it works to consolidate and strengthen a sandy surface, reduces the absorbency of a mineral substrate, and can also act to immobilise salts within the capillaries.

Koster deuxan 2C.

Guidance for specification option:

Koster Deuxan 2C:

• A liquid-applied thick film bitumen rubber membrane, which provides a thick, crack-bridging, water and gas proof finish to external basement slabs, walls and podium decks.
• Koster Deuxan 2C is either hand or spray applied to a primed and prepared substrate to achieve a 4 mm dry film thickness in two coats.
• Water-based.
• Koster Deuxan 2C satisfies the relevant requirements of NHBC Standards, chapter 5.4 'Waterproofing of basements and other below-ground structures'. 
• With the use of ancillary and complementary Koster products, it can encompass awkward detailing areas such as expansion joints and pipe penetrations to ensure a full and continuous waterproofing system.
• Individual project specific detailed drawings are available along with expert technical advice.

Koster NB1 grey.

Guidance for specification option:

• A liquid-applied mineral waterproofing coating which contains crystallizing agents.
• Suitable for positive side and negative side waterproofing. 
• Koster NB1 Grey possesses excellent pressure and abrasion resistance, as well as chemical and sulphate resistance.
• When used as a part of this system, it is applied to the bottom area of the basement wall (1 m minimum), over the construction joint and down onto the vertical face of the slab. 
• The NB1 Grey prevents residual water in the substrate or construction joint from interfering with the cure of the primary waterproofing layer.
• It is brush or spray applied in a single-coat application.

Koster glass fiber mesh.

Guidance for specification option:

• This is a reinforcing fabric which has an extremely high tear resistance. 
• It is installed between the coatings of Koster deuxan 2C. 
• It is to be used on all substrates which are likely to be exposed to pressurised water and/ or in danger of cracking.