BRITISHjoist sealBOARD OFAGRÉMENTCERTIFICATE No 01/3838
joist sealthe joist sealfrom ManthorpeABCManthorpe has developed arevolutionary product range to solve theproblem of air leakage around timberjoists and ‘I’ beams and eliminate theneed for joist hangers.A Front sealing / location fl angeB Rear location fl anges providepositive pressure on sealC Cut out tabs to fi t restrainingstraps as requiredD Mortar keyE Foam gasket provides an air-tight sealEDDesigned to meet the requirements of Part L Building Regulationsregarding increased insulation and air leakage, Manthorpe’sJoistSeal provides an effective and easy to install solution.The ProblemThe Robust Construction Details suggest that timberjoists should no longer be built into the internalblockwork skin of an external wall as the shrinkage ofjoists and mortar allows air leakage into the cavity.To meet Part L and Part E Regulations, an alternativeto the traditional construction method is to use joisthangers to suspend joists. However, this slows downthe building process and they are more difficult to fi tcorrectly leading to reported structural problems suchas springy fl oors and, in some cases, total collapse.A joist hanger which has beenpoorly fi tted to a wall:the reason why some moderntimber fl oors are springy.The SolutionAs an alternative to the Robust Construction Details suggestion,and to address these problems, Manthorpe has developed theJoistSeal which fi ts over the joist end before being built into theblockwork in the traditional manner. Effectively, the JoistSealis a box built into the inner wall which is sealed to the masonryto form an air-tight joint. The fl oor joist fi ts into this box.During the drying out period, the timber fl oor joist can shrinkwithin the product without the seal between the box and themasonry being affected, thus complying to Part L.Key Benefi ts:• Substantial time savings on site• Compliant to Building Regulations Part L (Air Leakage)• 1 Hour Fire Tested (Warrington Fire Research)in party wall detail.
The RangeWhy Use Manthorpe JoistSeals?All sectors of the construction industry agree thatJoistSeals are of great benefi t to the builder.Throughout the development of this product range,Manthorpe has sought information and recommendationsfrom industry experts to assist in the design of the ultimateproduct to combat air leakage around timber joistsand comply with regulations regarding acoustics.TestingTests carried out at CERAM Building Technologyproved that Manthorpe’s JoistSeals were moreeffective at preventing air leakage than pointing witha sealant, and even out-performed joist hangers.Manthorpe’s JoistSeals are suitable for use inparty walls and have been tested for fi re resistanceat Warrington Fire Research Centre.The JoistSeal fi ts all common joist sizes.Manthorpe has a comprehensive range of seals to fi t all situationsi.e. for different joist heights and widths as well as for varyingblock widths.Restraining straps can be used in conjunction with the JoistSealby trimming slits into the product at designated points.As a unique safety feature, Manthorpe’s range of joist seals ismanufactured in translucent polypropylene to allow a clear viewof the joist resting on the blockwork inside the product.Every product has a black compression seal to enhancethermal effi ciency.If using joists smaller than the JoistSeal, the joist should bepacked using a suitable dry timber material or mineral fi bre toprevent movement and preserve the structural, thermal andfi re integrity of the structure.
Manthorpe Building Products LtdManthorpe HouseBrittain DriveCodnor Gate Business ParkRipley, Derbyshire DE5 3NDTel: 01773 514 200Email: email@example.comReferences:Conservation of Fuel and PowerApproved Document L 2002Robust details Part EManthorpe QualityManthorpe manufactures a range of ventilation andbuilding products at its headquarters in Derbyshire,under an ISO9001 Quality Assurance Scheme.All products are designed to comply with therelevant current Building Standards when fi tted inaccordance with the manufacturer’s instructions.The company maintains a policy of continuousdevelopment of its product range and reserves theright to amend the specifi cations without notice.