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London Business Matters

72 MEMBER PROFILES Protecting our historic and listed buildings With many historic and listed buildings not benefiting from modern forms of protection, they are often subject to the detrimental effects of damp. The challenge when dealing with buildings of special architectural or historic interest is to maintain structural and aesthetic integrity, whilst still achieving the desired effect. Meeting Listed Building Damp Proofing Walls Above Ground Damp Proofing Walls Above Ground Requirements – Rising Damp – Penetrating Damp WHEN TREATING damp in historic and listed If completely dry and untainted internal buildings, it is important that any products meet surfaces are required, membranes are the ideal with the stringent Listed Building Requirements. products for providing a barrier between the Many products require surface preparation damp construction and internal finish. The air techniques that are unacceptable due to the gap created by the studs of cuspated damp detrimental effect on the structure, which are proof membranes provides an equilibrium often irreversible. of moisture-laden air, maintaining the However, some products, such as natural state of the structure and prolonging damp proofing membranes, can still be its longevity whilst protecting internal sympathetically applied with little preparation finishes from damp. Internally applied damp and minimal fixings. Once installed, the proof membranes should be installed to membrane provides an impervious barrier approximately 200mm above the highest between the damp surface and the new evidence of rising dampness so as to allow the internal wall, preventing moisture and natural vapour drive to continue unimpeded vapour from affecting internal finishes. When through the walls above the treatment. supplemented by drainage, this is one of the most effective forms of protection. Penetrating damp should be treated externally at the source of the water entry. Water in its liquid state can only pass through a wall if there are defects large enough to accommodate it, so it is these defects that require repair. Many old walls were designed to be dampened by wind-driven rain with the expectation that they would dry out before any moisture reached the internal surface. However, persistent rain means that this can sometimes happen and it shows as penetrating damp. The solution is specially formulated external treatments, which penetrate into the wall materials, block the capillaries and prevent moisture from entering. Breathability also allows residual moisture to exit, resulting in damp-free internal walls that are dryer, warmer, and have a dramatically reduced probability of internal condensation. Treating Areas Below Ground Subterranean areas will always be subject to penetrating damp due to the natural watercourses within permeable soil, which channel the water like pipes. Saturated soil develops a head of pressure surrounding the subterranean structure, leading to water ingress through gaps and joints in the construction. Habitable or useable below ground areas therefore need to be waterproofed. For historic and listed buildings, cavity drainage systems are ideally suited for this application. When installed by qualified contractors, the systems depressurise and collect water that enters the structure, before removing it safely. Internal finishes are isolated from the water, leaving a dry and habitable space for the occupier even in the most demanding situations. Newton recommends that our structural waterproofing and damp proofing systems are installed by one of our nationwide network of Newton Specialist Basement Contractors (NSBC). NSBCs have been trained by Newton and offer full professional indemnity on design and insurance backed guarantees on installation. i 01732 360 095 www.newtonwaterproofing.co.uk E: info@newtonwaterproofing.co.uk Figure 2: This dry, clean internal finish at the Grade 1 Listed St George’s Hall in Liverpool was achieved through the application of Newton meshed damp proofing membranes in order to act as a damp barrier. Here we can see the membrane both pre- and post-application of the wall finish. Figure 1: Newton cavity drain membranes were effectively applied to the interior vaults of the Grade 1 Listed Royal Courts of Justice, London. Here we can see the completed system, prior to the application of the internal finish. The Guide to Waterproofing COMPLETE WATERPROOFING SOLUTIONS FOR NEW AND EXISTING STRUCTURES CONTACT US FOR YOUR FREE COPY T: +44 (0)1732 360 095 W: newtonwaterproofing.co.uk E: info@newtonwaterproofing.co.uk Newton_LBM_November_Edition.indd 1 24/11/2016 16:12:31


London Business Matters
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