ABSTRACT

NaturalstonekerbstoBritishStandard435 Thoughnotmuchusednowadaysbecauseofthehighcost,naturalstoneisbetter lookingandharderwearingthanconcrete.BritishStandard435givesthe requirementsforkerbs,whichmustbemadeofigneousrocksuchasbasalt,gabbro, graniteandporphyry-inpracticethismeanswhinstoneorgranite.Twoprofiles arespecifiedintheBS-edgekerbandflatkerb,withaminimumlengthof 600mm.NomaximumlengthisgivenintheStandard,butastherearenotmany paviourscapableofhandlingquartertonnestones,kerbsmustbemadeasshortas possibleforeasyworking.ThesizesgivenintheStandardare:

edgekerb600mmlong 200mmwide300mmdeep(noreferencesaregivenintheStandard) 150300 150250 150200 125250 flatkerb600mmlong 300mmwide200mmdeep(noreferencesaregivenintheStandard) 300150 250125 250150

Becauseworkinghardstonesisdifficultandexpensive,onlythetopand 125mmofthefrontand75mmofthebackaredressed.DressingmaybeTypeA 'finepicked';typeB'singleaxed'or'nidged';orTypeC'roughpunched'.Rough puncheddressingismostsuitableforkerbsasthecoarsertexturegivesbetter footholdandwearslonger.Curvedstonekerbsandthechannels.tomatch,are availablemadetoordertotheradiusspecified,buttheyareveryexpensive.A cheaperwayofturningcornersistouseoneofthetwostandardquadrants;Type Xisasegmentofacircle,andTypeYisaquartercircle.Boththesearemadeto ordertothesizespecifiedbythelandscapedesigner.Thefoundations,layingand beddingofnaturalstonekerbsaresimilartothosespecifiedforprecastconcrete kerbs.Reusednaturalstonekerbsarenotlikelytocomplywiththestandardsizes andprofiles.