[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-657896-105":59,"doc-detail-657896-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","statewide-code-interpretation-no-19-02-horizontal-wet-venting","STATEWIDE CODE INTERPRETATION - No. 19-02 - Horizontal Wet Venting","","Statewide code interpretation No. 19-02 addresses Horizontal Wet Venting under OAR 918-008-0110 and the 2026 Oregon Plumbing Specialty Code (OPSC) Section 908.2. It confirms that bathroom-group connections remain required to be independent and horizontal, explains there is no maximum slope but a uniform 1/4 inch per foot minimum slope requirement, and clarifies that all fixtures in a bathroom group must connect upstream of the water closet.",{"@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":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/statewide-code-interpretation-no-19-02-horizontal-wet-venting/657896/",{"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/statewide-code-interpretation-no-19-02-horizontal-wet-venting/657896.png","ImageObject",300,407,{"name":92,"@type":93},"Adam","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-26",true,{"@type":102,"interactionType":103,"userInteractionCount":8},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Are connections still required to be independent and horizontal after changes to OPSC Section 908.2?","Question",{"text":112,"@type":113},"Yes. The interpretation states the horizontal wet vent design requires each fixture within the bathroom group to connect independently and laterally.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"Is there a maximum slope or grade requirement for the horizontal wet vent section?",{"text":117,"@type":113},"No maximum is stated. Section 708.1 requires a minimum 1/4 inch per foot, and a uniform slope of 1/4 inch per foot must be maintained.",{"name":119,"@type":110,"acceptedAnswer":120},"Can a three-fixture bathroom use a horizontal wet vent for two fixtures and independently vent the third downstream of the water closet?",{"text":121,"@type":113},"No. The interpretation requires all fixtures within the bathroom group to connect upstream from the water closet.","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},657896,1792993700,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":8,"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},1374404737137,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","STATEWIDE CODE INTERPRETATION  \nNO. 19-02  \nHorizontal Wet Venting  \nIn accordance with OAR 918-008-0110, the information contained in this statewide code interpretation is legally binding on any party involved in activities regulated by applicable Oregon law, applicable Oregon regulations or the state building code. If the information contained in this statewide code interpretation is cited as a basis for a civil infraction, a representative of the jurisdiction must cite the interpretation number found in this document.  \nCode reference  \n2026 Oregon Plumbing Specialty Code (OPSC)—Section 908.2  \nDates  \nIssued: March 2019  \nLast updated: Oct. 1, 2026  \nQuestions / Answers  \n1. Section 908.2 has changed in the OPSC and does not contain the same language as previous editions stating that connections shall be independent and horizontal. Are the connections still required to be independent and horizontal?  \nYes. The design of the horizontal wet vent requires that each fixture within the bathroom group connect independently and laterally. This reduces the potential to interrupt the airflow above the water level. Therefore, the lateral connections are critical points of the system.  \n2. Section 908.2 does not indicate a maximum slope. Section 708.1 requires drainage piping to be not less than 1/4 inch per foot, and horizontal is defined in Section 210.0 to make an angle of less than 45 degrees with the horizontal. Is there a maximum grade requirement for the horizontal wet vent section?  \nNo. Section 708.1 requires a minimum 1/4 inch per foot. Although there is not a maximum requirement, a uniform slope of 1/4 inch per foot shall be maintained. This is critical to allow the drain to have sufficient air volume within the wet vent system and prevent surges of water from cresting the crown of the pipe.  \n3. If a bathroom consists of three fixtures, is it permissible that two of the fixtures be installed on a horizontal wet vent and the third fixture be conventionally (independently) vented and connected to the drainage system downstream of the water closet?  \nNo. All fixtures within the bathroom group shall connect upstream from the water closet.  \nThere is some confusion with the term “any combination” in the OPSC definition of “Bathroom Group”, also a change in the adopted national model code. This change was made to clarify that a powder bath is allowed to be horizontally wet vented; it was not intended to delete fixtures within the bathroom group from connecting upstream of the water closet as required in Section 908.2.4.  \nAnalysis  \nThe concept of horizontal wet venting is the same as combination waste and vent systems and circuit vent systems with minimal differences. The design of all these types of horizontal group venting allows the drainpipe to be wet vented, therefore sharing air space above the mean water surface in a horizontal drain. This air space cannot have excessive surges cresting above the mean water surface, offsets in the system, vertical discharges, excessive grade, or common fixture connections which would cause disruption of this air flow.  \nContact  \nVisit the division website to contact a building code specialist.","cbCaiq9ppVLsHz7D","https://ap.wps.com/l/cbCaiq9ppVLsHz7D","pdf",243024,"English","# Questions / Answers\n## Section 908.2 changes and independence/horizontal requirements\n## Maximum slope or grade requirement\n## Bathroom group fixtures and upstream connection rule\n# Analysis\n## Concept of horizontal wet venting and air flow limitations","[{\"question\":\"Are connections still required to be independent and horizontal after changes to OPSC Section 908.2?\",\"answer\":\"Yes. The interpretation states the horizontal wet vent design requires each fixture within the bathroom group to connect independently and laterally.\"},{\"question\":\"Is there a maximum slope or grade requirement for the horizontal wet vent section?\",\"answer\":\"No maximum is stated. Section 708.1 requires a minimum 1/4 inch per foot, and a uniform slope of 1/4 inch per foot must be maintained.\"},{\"question\":\"Can a three-fixture bathroom use a horizontal wet vent for two fixtures and independently vent the third downstream of the water closet?\",\"answer\":\"No. The interpretation requires all fixtures within the bathroom group to connect upstream from the water closet.\"}]","STATEWIDE CODE INTERPRETATION - No. 19-02 - Horizontal Wet Venting | PDF"]