​​​​Solutions for Below Ground Waterproofing

Protection of below ground structures against water ingress to help make your structure BS 8102:2022 compliant​

• Innovative pore blocker technology
• System warranty up to 25 years
• Single source system approach
• Full site support and training
• BS 8102 & NHBC compliant
• BBA approved systems

Product Offering

• MasterLife WP 754 – Pre-and ​​​​Post-applied FPO waterproofing membrane for below ground concrete structures​​

• MasterLife WP 799 – Water resisting admixture for concrete
• MasterLife WP 910 and MasterLife WP 912 System – Hydrophillic waterbar and mastic system for construction joints
• MasterLife WP 925​ – Hydrophillic rings and plugs for formwork tie holes​
  

Grades of Waterproofing

BS8102:2022 has recently been revised; one of the most noticeable changes to the standard is separating Grade 1 into two grades, Grade 1a and Grade 1b. The latest Code of Practice states the following, when designing to a ‘waterproofing grade’:​

• Grade 1a Seepage and damp areas from internal and external sources are tolerable, where this does not impact on the proposed use of below ground structure.
• Grade 1b No seepage. Damp areas from internal and external sources are tolerable.
  
• Grade 2 No seepage is acceptable. Damp areas as a result of internal air moisture/ condensation are tolerable; measures might be required to manage water vapour/condensation.
  
• Grade 3 No water ingress or damp areas is acceptable. Ventilation, dehumidification or air conditioning necessary; appropriate to the intended use. The agreed grade should meet with client’s expectations for the intended use of the below ground space. Reducing the grade could increase the risk of not meeting the expectations of the client. The grade of waterproofing protection should be agreed at the earliest stage. Reducing the grade increases the risk. ​Seepage has been defined separately to damp, and specifically mentioned as either acceptable or unacceptable depending on the Grade of protection.

Types of Waterproofing Protection

BS 8102 classifies three grades of waterproofing protection.

• Type A barrier protection against water ingress which is dependent on a separate barrier system, applied to the structure. Varying types of bonded sheet membranes are typically used.
  
• Type B structurally integral protection against water ingress, which is provided by the structure. Structures providing Type B protection should be constructed of reinforced concrete of structural steel and designed in accordance with the relevant part of BS EN 1992 (all parts) respectively. This type of waterproofing protection is actually integrated into the concrete structure and typical products used include water resisting admixtures compiling with Table 9 of BS EN 934-2:2009 (Admixtures for concrete, mortar and grout) for watertight concrete combined with appropriate joint sealing systems for connections, construction and movement joints. Concrete structures containing a water resistance admixture should be deemed to have a lower degree of water/ vapour transmission when the design of the concretemix and the casting of the structure is adequately supervised and the admixture is assesed and certified (see BS 8102:2022 9.2.1.3)
  
• Type C drained protection against water ingress into usable spaces. Type C waterproofing protection manages water that penetrates the external shell of the structure, by collecting it in a cavity formed between the external wall and internal lining / wall. There is a permanent reliance on this cavity to collect groundwater seepage and direct it to a suitable discharge point, e.g. drains of a sump for removal by gravity drainage of mechanical pumping.
  

National House Building Council (NHBC) Risk-based Design

Chapter 5.4 (Waterproofing of basements and other below ground structures) requires that waterproofing design should be appropriate to the risk and generally assume exposure to a full height of water during the design life of the building. Where ‘Grade 3 protection’ is required, and the below ground wall retains more than 600mm, measured from the lowest finished floor level, the waterproofing design should include a combination of two of the Types of waterproofing systems.
Where Grade 2 waterproofing is required to walls retaining ground greater than 600mm, Type A systems that are not fully bonded should only be used as part of a combined system. combined systems include:

• Type A and Type B
• ​Type A and Type C
• ​Type B and Type C

Where there is any doubt about use, Grade 3 protection should be provided. Grade 3 structures built with a Type A and Type B waterproofing system would typically be:

• Storage areas (moisture sensitive goods)
• Electrical plant rooms
• Ventilated residential units and offices
• Restaurants and commercial areas
• Leisure facilities
• Residential areas
• Computer rooms
• Archive Rooms

Grade 2 structures built with a Type A and Type B waterproofing system would typically be:

• Underground car parks
• Plant rooms
• Workshops
• ​Storage areas (moisture unaffected goods)

Warranty

We are pleased to provide you with the following warranties, which align with our various product offerings as outlined. At Master Builders Solutions, we have a well-defined process to ensure that all eligible warranties are promptly issued upon the completion of your project. 

​​​	​Watertight Max Solution Type A and B waterproofing construction in accordance with BS 8102:2022 25 – year warranty with Three lines of defence: MasterLife WP 754 pre-applied FPO waterproofing membrane ​MasterLife WP 799 plus MasterLife WP 900 re-injectable hose waterstop system
​	Watertight Pro Solution Type A and B waterproofing construction in accordance with BS 8102:2022 20 – year warranty with Two lines of defence: MasterLife WP 754 pre-applied FPO waterproofing membrane ​MasterLife WP 799 plus MasterLife WP 910/912 hydroswelling waterbar
​	​ Watertight Re-injectable Solution Type B waterproofing construction in accordance with BS 8102:2022 20 – year warranty with Two lines of defence: MasterLife WP 799 Watertight admixture MasterLife WP 900 re-injectable hose waterstop system with MasterRoc MP 307​​
​	​​ Watertight Solution Type B waterproofing construction in accordance with BS 8102:2022 15 – year warranty with One line of defence: MasterLife WP 799 plus MasterLife WP 910/912 hydroswelling waterbar

Site Support

Master Builders Solutions have a dedicated site services team to support our customer base when working with our watertight product range.

We can be involved in your project at an early stage and we are more than happy to offer technical support with construction joints, pour layouts and aspect ratios which can be discussed with our local team.

We will work in conjunction with your appointed ready-mix supplier to confirm that the watertight concrete mix meets our technical specifications whilst ensuring the addition of our material is carried out within QA guidelines.

For more information on Site Support please contact:
Aaron Myers C.S.S.W
Technical Site Services, Watertight Systems UK
+44 (0)7798 872529
aaron.myers@masterbuilders.com​

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Specifications

Water is the most destructive weathering element for concrete, masonry, steel and stone structures, damaging or destroying more buildings and structures than war or natural disasters. Whether above-ground or below ground, all buildings must be able to resist unwanted water in some respect, in the form of rainwater, moisture or hydrostatic pressure. Hydraulic civil structures face yet more challenges in withstanding the ongoing effects of constant immersion.

Good waterproofing, or water resistance, can be the key factor in ensuring a structure’s longevity, yet the importance of this facet of structural design is not always given the attention it warrants. The majority of problems with water ingress occur in a relatively small proportion of a structure’s surface area, often where design details meet. Careful consideration at the design stage can limit cracks, leaks and potentially serious structural damage over a structure’s lifecycle, providing that trades work together at the construction stage to implement design details successfully.

With all this in mind we can offer a specification with a complete range of products to help make your structure BS 8102 compliant.

For more information on our specifications please contact:
Stuart Davidson (C.S.S.W)
Specification Manager, Watertight Systems UK
+44 (0)7917 233229
stuart.davidson@masterbuilders.com