[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-663545-105":59,"doc-detail-663545-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","suggested-guidelines-for-watertight-chimney-construction-water-resistant-practices","Suggested Guidelines for Watertight Chimney Construction - Water-Resistant Practices","","Provides practical guidance for designing and building watertight masonry chimneys to prevent moisture intrusion, efflorescence, and freeze-thaw deterioration. Covers critical details at the roof/chimney intersection, including properly lapped base flashing, turned-up flashing into mortar joints, and sealed stepped segments. Explains chimney cap construction choices, sloping and overhang requirements, drip-edge integration, and creating a void between the cap and clay flue liner with compressible, caulked fill. Recommends through-wall flashing as a secondary defense when rain still penetrates past the cap.",{"@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":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/suggested-guidelines-for-watertight-chimney-construction-water-resistant-practices/663545/",{"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/suggested-guidelines-for-watertight-chimney-construction-water-resistant-practices/663545.png","ImageObject",300,407,{"name":92,"@type":93},"Chumphorn","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-28",true,{"@type":102,"interactionType":103,"userInteractionCount":14},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why is a chimney considered one of the most vulnerable parts of a structure?","Question",{"text":112,"@type":113},"Because it is exposed to weathering on all sides. If water enters and moisture control steps are not followed, it can cause efflorescence and freeze-thaw damage.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What are the key waterproofing steps at the roof/chimney intersection?",{"text":117,"@type":113},"Install base flashing on top of the roof sheathing, extend at least 4 inches under roof shingles, turn up flashing at least four inches before inserting into a raked mortar joint, and lap stepped flashing segments at least three inches and seal them.",{"name":119,"@type":110,"acceptedAnswer":120},"How should the chimney cap be constructed to keep moisture out?",{"text":121,"@type":113},"Design the cap to keep moisture from entering the system, avoid mortar-wash/parging, use cast-in-place concrete, precast concrete, or stone, slope it away from the flue, overhang the chimney wall at least two inches with a drip edge, and include a void between the cap and flue filled with compressible material and caulk.","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},663545,1793229061,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":14,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":14,"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":24},2336475401981,"https://ap-avatar.wpscdn.com/avatar/22000c94efd8d5204d?x-image-process=image/resize,m_fixed,w_180,h_180&k=1786935347598174694","| Related External Links   |\n| --- |\n| BIA Tech Notes   |\n| NCMA Techical Notes   |\n\nSuggested Guidelines for Watertight ChimneyConstruction  \nBy Jason Yana  \n# Introduction\n\nA chimney is one of the most vulnerable parts of a structure because it is exposed to weathering onall sides.If the proper steps are not taken,both on the drawing board and in the field,water canenter the chimney and cause efflorescence and eventually freeze thaw damage.However,if industryguidelines are followed,chimneys can be designed to be watertight for decades.As with most formsof masonry construction,steps should be taken to prevent moisture damage.  \n# Roof /Chimney intersection\n\nThe intersection between the chimney and the roof is a critical spot where several trades have tocome together to provide a watertight joint.Base flashing should be installed on top of the roofsheathing,extending horizontally under roof shingles for a minimum of 4 inches.As shown in figure  \n1,flashing should be turned up a minimum of four inches before it is inserted into a raked mortarjoint and caulked.As shown with the dotted lines,the stepped flashing segments should be lapped atleast three inches and sealed.Prefabricated corners are also suggested to properly protect theintersection.  \nFigure 1:Chimney Construction   \n# Chimney Cap\n\nLook at figure 2 for a graphical representation of how a cap is constructed.The chimney cap shouldbe designed to keep moisture from entering the system.Caps should not be constructed as a mortarwash,which is simply parging the surface with mortar.The chimney cap should be made with cast inplace concrete,precast concrete or stone.The chimney cap should be sloped away from the flue todirect water out of harms way.The cap should overhang the chimney wall at least two inches andshould have a drip edge cast into the overhang.Rain water is now directed off of the top of thechimney and drips off of the overhang.  \nBecause the concrete cap and clay flue liner are different materials having different thermalexpansion characteristics,there should be a void left between the cap and the flue.This void shouldbe filled with a compressible material and caulked.This allows both materials to moveindependently,while the sealant keeps moisture out.  \nFigure 2:Chimney Cap Construction  \nRAIN CAP/SPARKARRESTORSUGGESTED AND MAY BEREQUIRED BY LOCAL CODE  \nAll of the measures discussed above are focused on keeping water out of the chimney.Although thesemeasures can protect the chimney from moisture,they are not foolproof.Some water will still find it's waypast the cap.For this reason,through wall flashing should be placed under the cap as a second line ofdefense against moisture penetration.The flashing is adhered to the flue liner,extends horizontally underthe cap and is extended beyond the face of the wall.","cbCaieExcC0Xnwlg","https://ap.wps.com/l/cbCaieExcC0Xnwlg","pdf",389024,"English","# Introduction\n# Roof /Chimney intersection\n# Chimney Cap","[{\"question\":\"Why is a chimney considered one of the most vulnerable parts of a structure?\",\"answer\":\"Because it is exposed to weathering on all sides. If water enters and moisture control steps are not followed, it can cause efflorescence and freeze-thaw damage.\"},{\"question\":\"What are the key waterproofing steps at the roof/chimney intersection?\",\"answer\":\"Install base flashing on top of the roof sheathing, extend at least 4 inches under roof shingles, turn up flashing at least four inches before inserting into a raked mortar joint, and lap stepped flashing segments at least three inches and seal them.\"},{\"question\":\"How should the chimney cap be constructed to keep moisture out?\",\"answer\":\"Design the cap to keep moisture from entering the system, avoid mortar-wash/parging, use cast-in-place concrete, precast concrete, or stone, slope it away from the flue, overhang the chimney wall at least two inches with a drip edge, and include a void between the cap and flue filled with compressible material and caulk.\"}]","Suggested Guidelines for Watertight Chimney Construction - Water-Resistant Practices | PDF"]