[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-649713-105":59,"doc-detail-649713-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","existing-house-roof-construction-specifications","Existing House - Roof Construction - Specifications","","Roof, wall, and floor construction requirements for an existing house and front porch extension are specified, focusing on matching roof slates, timber battens, rafters, purlins, insulation layers, ventilation, and airtight membrane details. The document also defines cavity wall build-up with cavity board insulation, firestopping barriers, damp-proof course provisions, and sealing at junctions and openings. Window and door U-value targets, DPC details for cills, emergency escape opening dimensions, and safety glazing rules are included, alongside foundation and radon protective DPM requirements.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/existing-house-roof-construction-specifications/649713/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/existing-house-roof-construction-specifications/649713.png","ImageObject",300,407,{"name":92,"@type":93},"cimolpedes","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-09","2026-10-24",true,{"@type":102,"interactionType":103,"userInteractionCount":24},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What roof elements must be used to match the existing roof?","Question",{"text":112,"@type":113},"Use selected roof slates matched to the existing roof, on 50x35 treated timber battens, with a breather membrane on 100x44 timber rafters at 600 CRS, supported on 225x75 purlins and ceiling joists at 600 CRS.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How is insulation handled to avoid cold bridging at junctions and at eaves?",{"text":117,"@type":113},"Insulation is continued up behind window cills to prevent cold bridging, and insulation continuity at the eaves is ensured using a proprietary eaves ventilator so ventilation to the attic is maintained.",{"name":119,"@type":110,"acceptedAnswer":120},"What are the emergency escape opening requirements for windows?",{"text":121,"@type":113},"At least one window in each room must provide an unobstructed opening of at least 850mm high and 500mm wide, with the cill between 800mm and 1100mm above finished floor level; glazing with a cill below 800mm must use safety glazing.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},649713,1792804464,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":24,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":8,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":81,"preview_page_count":4},962094243610,"https://ap-avatar.wpscdn.com/davatar_3d24733baf745e90a7e4bdd5f77d97b2","Existing House    \nRoof to consist of selected  \nslates to match existing roof on 50x35 treated timber battens on Tegral Ventrex breather membrane or similar on 100x44 rafters @ 600 crs, supported on 225x75 purlins propped at max. 3Mcrs off partition wall or specially designed supports with 150x44 ceiling joists @ 600 crs with 400 fibreglass quilt insulation, 200 between joists &  \n200 laid over with 13 gypsum plasterboard ceiling with skim finish to underside.  \nFront porch extension  \nCavity closed with firestopping insulant cavity barrier  \nor  \nEnsure new lead cavity trays & flashings to be provided to junction of walls & new roofs  \nto prevent water ingress Existing window to be  \nremoved shown dashed  \nEx. window removed & replaced with height of cill to be altered to accommodate new slate roof  \n220 overhang to kitchen extension roof only to match existing. All other roofs to have 450 overhang.  \n28°  \nStepped dpc to all window/door heads  \nEnsure continuity of insulation at eaves & proprietary eaves ventilator to ensure ventilation to attic is maintained  \n350 675  \n450  \n350 cavity wall with 100 conc block inner & outer leaf with 150 cavity containing  \n100 Xtratherm partial fill cavity board insulation with selected plaster finish to inside & outside  \nSitting Room  \n25 vertical upstand  \ninsulation  \nOpe formed in wall to owners requirements  \nexisting  \nExisting window removed & new ope formed  \nKitchen  \nExtension  \nInsulation carried up behind window cill to prevent cold bridging  \n220  \n1,050  \n150 powerfloated concrete slab on  \n500 gauge polythene on 100 Xtratherm Hyfloor rigid flooring insulation with 25 vertical upstands at wall/floor junctions on 1200 gauge radon protective DPM on 50 sandblinding on min 225 compacted & consolidated hardcore.  \n1050x350 reinforced conc foundations under all external walls  \n2,660  \n2,540 to kitchen extension only  \nCross Section A-A  \nROOF CONSTRUCTION. TO CONSIST OF SELECTED ROOF SLATES TO MATCH EXISTING ON 50x35 SOFTWOOD BATTENS TO GAUGE ON TEGRAL VENTREX BREATHER MEMBRANE OR SIMILAR ON 100x44 CUT TIMBER RAFTERS @600 CRS WITH TREATED ENDS MEETING AT RIDGEBOARD & BIRDSMOUTH JOINTED OVER 100x75 PRESERVATIVE TREATED WALLPLATE. RAFTERS SUPPORTED ON 225x75 PURLINS PROPPED AT MAX. 3MCRS OFF PARTITION WALL OR SPECIALLY DESIGNED SUPPORTS WITH 150x44 CEILING JOISTS @ 600 CRS TO FORM CEILING. WALLPLATES TO BE FIXED AND HELD IN POSITION WITH GALVANIZED HOLDING DOWN STRAPS @ 2M c/c MAX. STAGGERED INTERNALLY & EXTERNALLY AND CARRIED DOWN 450MM ON BOTH SIDES OF WALL. WHERE WALLPLATES ARE BUTT JOINTED STRAPS ARE TO BE PROVIDED AT 400 c/c ON EITHER SIDE OF JOINT.  \nINSULATION-  400 ROCKWOOL INSULATION TO FLAT CEILING CONSISTING OF 200  \nFITTED BETWEEN JOISTS & ADDITIONAL 200 LAID OVER, WITH GLIDEVALE EAVES VENTILATOR OR SIMILAR TO BE LOCATED AT EAVES TO ENSURE CONTINUOUS VENTILATED AIR GAP TO ROOF SPACE. 12.5 PLASTERBOARD & SKIM FINISH TO UNDERSIDE OF JOISTS. AN AIRTIGHT MEMBRANE TO BE FITTED TO INSIDE OF CEILING JOISTS & APPLIED IN ACCORDANCE WITH MANUFACTURERS INSTRUCTIONS.  \nALL LEAD USED IN ROOF CONSTRUCTION TO BE CODE 4 OR 5 LEAD TO BS. 1178.  \nLEAD TO VALLEYS TO BE NOT LESS THAN 500 WIDE AND IN LENGTHS OF NOT MORE THAN 1.5M TO BE LAPPED 150 AT EACH LENGTH. LEAD VALLEYS TO BE SUPPORTED ON TREATED VALLEY BOARDS. TILES TO BE CUT & RAKED ALLOWING 100 OPEN CHANNEL. ALL ROOF CONSTRUCTION TO BE CARRIED OUT IN ACCORDANCE WITH CURRENT BUILDING REGULATIONS.  \nWALL CONSTRUCTION.  \nEXTERNAL WALLS TO CONSIST OF SELECTED KNAPP PLASTER FINISH ON 100 CONCRETE BLOCK OUTER LEAF, 150 CAVITY CONTAINING 100 XTRATHERM PARTILA FILL CAVITY BOARD INSULATION FIXED TO 100 CONCRETE BLOCK INNER LEAF USING STAINLESS STEEL WALL TIES SPACED AT 750 c/c ON HORIZONTAL AND 450 c/c ON VERTICAL & STAGGERED. CONC BLOCK CAVITY WALL CLOSER TO BE OMITTED FROM TOP OF WALL TO PREVENT COLD BRIDGING & CAVITY CLOSED AT TOP USING A FIRESTOPPING CAVITY BARRIER. TOP TO ROWS OF CONC BLOCKWORK TO BE PROVIDED WITH WALL TIES AT 750c/c ","cbCaiiSiD4RVME0i","https://ap.wps.com/l/cbCaiiSiD4RVME0i","pdf",121760,"English","# Roof Construction\n## Wall Construction\n## Floor Construction\n## Foundations\n## Windows / Doors","[{\"question\":\"What roof elements must be used to match the existing roof?\",\"answer\":\"Use selected roof slates matched to the existing roof, on 50x35 treated timber battens, with a breather membrane on 100x44 timber rafters at 600 CRS, supported on 225x75 purlins and ceiling joists at 600 CRS.\"},{\"question\":\"How is insulation handled to avoid cold bridging at junctions and at eaves?\",\"answer\":\"Insulation is continued up behind window cills to prevent cold bridging, and insulation continuity at the eaves is ensured using a proprietary eaves ventilator so ventilation to the attic is maintained.\"},{\"question\":\"What are the emergency escape opening requirements for windows?\",\"answer\":\"At least one window in each room must provide an unobstructed opening of at least 850mm high and 500mm wide, with the cill between 800mm and 1100mm above finished floor level; glazing with a cill below 800mm must use safety glazing.\"}]","Existing House - Roof Construction - Specifications | PDF"]