Uniclass L31:N14:P7111 C1/SfB (16.9) Rn7 (J4) February Foundation Heave Protection

Transcription

1 Uniclass L31:N14:P7111 C1/SfB (16.9) Rn7 (J4) February 2008 Foundation Heave Protection

2 The safe, sure way to provide foundation protection Clayshield is the proven solution to protecting foundations against the effects of clay heave and soil movement on the side of deep trench foundations or the side and underside of ground beams. The Clayshield range includes solid Clayshield compressible fill, for use in deep trench foundations and to the side of ground beams; Clayshield Prestige, which incorporates a protective membrane; Castellated Clayshield, used to protect the underside of ground beams; Pile Collars and the innovative Clayshield Fixing Tool, which enables groundworkers to secure the protective boards in place while remaining outside the trench. All Clayshield boards are manufactured from expanded polystyrene (EPS), a lightweight, closed cell system with excellent compressibility. The cells in the board contain air, which compress under the pressure of expanding, wet clay soils, acting as a buffer between the ground and the foundation. Clayshield has a distinctive blue colouring allowing it to be easily identified on site. Clayshield Prestige - This latest innovation improves yet further the resilience of Clayshield during the pouring of concrete foundations by incorporating a protective membrane that enables the boards to resist the impact of the liquid concrete, ensuring they remain firmly in position and also acts as a slip membrane. The laminated layer overlaps the top edge of the board to allow temporary pinning at the top of the trench prior to final fixing to the trench wall. The Clayshield range is available through a network of insulation distributors and builders merchants throughout the UK. Application Position Clayshield Product Deep trench foundations Side Clayshield / Clayshield Prestige Ground beams Side / Underside Clayshield Ground beams Underside Castellated Clayshield / Clayshield Piles Encasement Pile Collars

3 Applications Clayshield is suitable for use in domestic, commercial and industrial foundations in heavy clay soils. Certification The solid Clayshield boards have been awarded BBA certificate No: 92/2854. The products are manufactured under a quality management system to BS EN ISO 9001:2000. Sustainability The environmental integrity of Clayshield is exceptional: Zero ODP (Ozone Depletion Potential) Zero GWP (Global Warming Potential) CFC, HFC and HCFC free Contains recycled content Boards are 100% recyclable Durability The compressible fill properties of Clayshield will remain effective for the life of the building. EPS is a dimensionally stable product, which is resistant to attack from bacteria, mould and fungi, and will not provide nutrient value for insects or vermin. It is also nontoxic and non-irritant. EPS does not bio-degrade and is unaffected by extremes in temperature. Specification Clause Clayshield should be described in specifications as: The foundation protection material shall be Clayshield (Prestige), mm thick, manufactured to BS EN 13163:2001 by Springvale EPS Ltd. BBA approved (certificate no.92/2854) expanded polystyrene boards to be installed according to Springvale s instructions. Refer to NBS Plus, clause E20/185 (Compressible Board Sub Structure Formwork) or for further information. Moisture Resistance EPS is resistant to water and can be installed in wet conditions without compromising its performance or longevity. NHBC Recommendations The NHBC publish Technical Standards detailing the recommended protection for trenchfill and ground beam foundations in clay areas. The tables in this literature can be used to determine the required thickness of Clayshield to achieve these recommendations. The data on clay shrinkage potential in this brochure can be viewed in NHBC Standards 2007 but you can also contact the Springvale Technical Office for assistance and advice on foundation design. Product information - Clayshield / Clayshield Prestige Property Clayshield Clayshield Prestige Board size (mm) 2400 x x 1200 Thickness (mm) 50, 75, 100, 200, , 75, 100 Effective Depth Deep trenches up to 3m, ground beams up to 600mm Colour Light blue Light blue with gridded grey laminate Product information - Castellated Clayshield Property Castellated Clayshield Board size (mm) 1200 lengths, in widths to suit the trench Thickness (mm) 100, 150, 200, 250 Colour Light blue Pile Collars Diameter (mm) W (mm) A (mm) W A H* A Pile Collar Design *H (mm) is determined by the thickness of protection below the beam

4 Clayshield Prestige secured around an external corner The Clayshield fixing tool pins the Clayshield Prestige boards to the trench wall Clayshield Prestige and the unique Clayshield fixing tool

5 Beamshield Plus Pile and beam foundation protected by Clayshield Deep trench foundation protected by Clayshield Perimeter strip Perimeter strip External ground level External ground level DPC min 150mm void DPC min 150mm void 250mm Castellated Clayshield starter unit (max. 300mm span) 100mm Claysheild Beamshield Plus standard full unit Beamshield Plus starter unit (max. 300mm span) Clayshield or Clayshield Prestige Beamshield Plus standard full unit Foundations protected by Clayshield and Castellated Clayshield NHBC 500mm toe The minimum underfloor void for suspended concrete beam floors is shown as required by N.H.B.C Chapter 4.2. Springvale Beamshield Plus is shown as the insulation between the beams NBS specification E60/297 (BBA Certificate 07/4411).

6 Once a site survey has been completed and the prevailing clay type identified, the Engineer can then determine the level and location of protection required for the foundations. Due consideration should be given to the location of trees and the characteristics of the ground beam. The tables below can be used to determine the required thickness of Clayshield to achieve NHBC recommendations. It is important to remember that Clayshield is designed to compress 50% in order to create the required void and therefore this should be allowed for in the overall thickness of Clayshield specified. Required thickness of Clayshield or Clayshield Prestige installed at the side of ground beams and deep trench foundations Shrinkage Potential Plasticity Index (%) NHBC Void Requirement (mm) Clayshield / Prestige Thickness (mm) High Medium Low Not required Required thickness of Clayshield board installed to the underside of ground beams Shrinkage Potential Plasticity Index (%) NHBC Void Requirement (mm) Clayshield / Prestige Thickness (mm) High Medium Low The thicknesses of Clayshield in each of the tables above are calculated to give a transmitted pressure through to the structure of 35kPa at 50% compression. Required thickness of Castellated Clayshield installed to the underside of ground beams Shrinkage Potential NHBC Void Requirement (mm) Castellated Clayshield Thickness (mm) Transmitted Load (kpa) High Medium or or 23 Low For the purposes of detailing on drawings, Clayheave requirements are often given as the void required under NHBC recommendations. This can be confused with the thickness of board required. Care should be taken to verify any detail where this could be misconstrued. Clayshield should not be used under floor slabs, please contact the Springvale technical office for futher advice. Site Work Handling and Storage Packs of Clayshield are delivered to site wrapped in polythene. Store panels in original packaging under cover and protected from direct sunlight. Keep boards above ground level and out of contact with solvents and materials containing volatile organic compounds such as coal tar, pitch and creosote. Do not expose to naked flame or other ignition sources during storage or installation. Health and Safety The material is chemically inert and requires no special treatment. Springvale supply a patented fixing tool to avoid the need to enter a trench in order to fix Clayshield boards. This is in line with Health and Safety and CDM regulations Installation Guide In order to ensure the safety of the installer, Springvale recommend the use of the Clayshield Fixing Tool. This specially designed tool removes the risk involved when fixing Clayshield boards. The operator can operate the tool standing above/outside the trench, avoiding any need to enter the trench. Information on the Fixing Tool and a full installation guide can be downloaded from or please contact our Technical Advisory Service on BRITISH BOARD OF BBA AGREMENT CERTIFICATE NO. 92/2854 ISO 9001:2000 FM Springvale EPS Ltd, Dinting Vale Business Park, Glossop, Derbyshire SK13 6LG T: F: E: sales@springvale.com Technical Advisory Service T: F: E: technical@springvale.com