{"id":10317,"date":"2017-04-25T08:00:34","date_gmt":"2017-04-25T13:00:34","guid":{"rendered":"http:\/\/www.cisco-eagle.com\/blog\/?p=10317"},"modified":"2026-03-18T10:41:37","modified_gmt":"2026-03-18T15:41:37","slug":"the-importance-of-pallet-rack-row-flue-space-and-ways-to-maintain-it","status":"publish","type":"post","link":"https:\/\/www.cisco-eagle.com\/blog\/2017\/04\/25\/the-importance-of-pallet-rack-row-flue-space-and-ways-to-maintain-it\/","title":{"rendered":"The Importance of Pallet Rack Row Flue Space &#8211; and Ways to Maintain it"},"content":{"rendered":"<p><img decoding=\"async\" style=\"width: 100%; max-width: 521px; height: auto;\" src=\"https:\/\/images.cisco-eagle.com\/blog\/wp-content\/uploads\/2017\/04\/RackFlue1.jpg\" alt=\"Pallet rack fire and flue space illustration\" \/><\/p>\n<p>The National Fire Protection Association (NFPA) has long required that pallet rack flue space remain clear at all times so that any fires can vent upward rather than outward, allowing sprinkler systems to activate faster. This vertical rise also helps slow fire spreading horizontally through a rack system. Flue space compliance is increasingly important to insurers and operators of warehouses and other industrial facilities. What can you do to help reduce issues with flue space obstruction?<\/p>\n<p><!--more--><\/p>\n<aside class=\"tldr-summary\" style=\"padding: 10px 20px 15px 25px; margin-bottom: 50px; border-radius: 15px; border: 2px solid #e4dddd; margin: 4px 10px 4px 10px; box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);\" data-type=\"summary\">\n<h4>TL;DR \u2013 Maintaining pallet rack flue space for fire safety<\/h4>\n<p>Maintaining clear flue space\u2014the vertical line of sight from floor to ceiling within a rack system\u2014is a critical fire-safety requirement mandated by the NFPA.<\/p>\n<p>These clearings allow heat to vent upward, triggering sprinkler systems faster and helping prevent fire from spreading horizontally. To ensure compliance, facilities use row spacers to maintain longitudinal gaps between rack rows and install rack safety straps or nets to prevent pallet push-through from obstructing these vital air passages.<\/p>\n<\/aside>\n<p><script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"BlogPosting\",\n  \"headline\": \"The Importance of Pallet Rack Row Flue Space \u2013 and Ways to Maintain it\",\n  \"name\": \"The Importance of Pallet Rack Row Flue Space \u2013 and Ways to Maintain it\",\n  \"description\": \"Maintaining clear flue space in pallet racks is essential for fire safety and NFPA compliance. Strategies to keep these vertical gaps open include using row spacers, installing safety straps or nets to prevent pallet push-through, and avoiding solid decking that blocks sprinkler penetration and encourages horizontal flame spread.\",\n  \"url\": \"https:\/\/www.cisco-eagle.com\/blog\/2017\/04\/25\/the-importance-of-pallet-rack-row-flue-space-and-ways-to-maintain-it\",\n  \"datePublished\": \"2017-04-25\",\n  \"author\": {\n    \"@type\": \"Person\",\n    \"name\": \"Scott Stone\"\n  }\n}\n<\/script><\/p>\n<h3>There are two types of pallet rack flue space:<\/h3>\n<ol>\n<li><strong>Longitudinal:<\/strong>\u00a0these are the spaces between rack rows set perpendicular to the direction of loading.\u00a0They&#8217;re simply the space between two rows of racks.<\/li>\n<li><strong>Transverse:<\/strong> these flues are the spaces between\u00a0pallets, and between pallets and uprights, facing the storage aisle.<\/li>\n<\/ol>\n<h4>Poor rack design and overly deep pallet loads<\/h4>\n<p>Be certain your pallets and loads are the right size for the depth of your rack.<\/p>\n<p>Well-designed storage systems allow the pallet to hang over the back beam in a double row, and maintain adequate <strong>longitudinal flue space<\/strong>\u00a0between rows. While the required longitudinal space may depend on local fire regulations and overall height and relate to the rack&#8217;s transverse flue space, the most common space is 6&#8243; between loads, which means that the space between rack uprights has to be greater than that.<\/p>\n<p><a href=\"https:\/\/www.cisco-eagle.com\/category\/2587\/pallet-rack-row-spacers\">Row spacers<\/a> are frequently installed to produce precise longitudinal flue space. To be effective, that space must have been correctly designed and the pallets within restrained so that they do not block a clear line, top-to-bottom longitudinal flue. Pallet push-through can result in blocked longitudinal flue space, even if the rows are adequately spaced.<\/p>\n<p>One mistake that is commonly made is to use a solid rack decking, which will encourage horizontal flame spread and will not allow sprinkler systems to adequately function.<\/p>\n<p>How do you combat that?<\/p>\n<p><img decoding=\"async\" style=\"width: 100%; float: right; max-width: 251px; height: auto; margin-bottom: 12px; margin-top: 12px; margin-left: 12px;\" src=\"https:\/\/images.cisco-eagle.com\/blog\/wp-content\/uploads\/2017\/04\/flue-space.jpg\" alt=\"rack flue space\" \/><\/p>\n<h4>Loading and forklift driver errors<\/h4>\n<p>One of the most common ways that longitudinal flue space gets choked is pallet push-through. This is a problem that isn&#8217;t difficult to solve, assuming that your pallet loads are not too deep\u00a0for your rack system.<\/p>\n<ul>\n<li>Some warehouses opt for an extra beam installed at the back of each bay for a more rigid solution. One issue with this is that it rigidly limits the size of pallets to very little overhang. It&#8217;s an easy way to go about it, but it is a very limiting method.<\/li>\n<li>One of the easiest solutions is to install\u00a0<a href=\"https:\/\/www.cisco-eagle.com\/category\/9392\/rack-safety-straps\">inexpensive rack straps <\/a>that attach to the back of each rack bay. These straps have give to them, which helps\u00a0the driver understand that he has pushed the pallet back far enough without damaging the rack.<\/li>\n<li><a href=\"https:\/\/www.cisco-eagle.com\/category\/849\/pallet-rack-safety-netting\">Rack safety nets<\/a> can also restrain loads away from the longitudinal flue when installed on the back of rack rows. These cover the entire bay, and are more frequently used to stop product falls on the outer aisles.<\/li>\n<li>Also, there are bolt-on brackets that attach to step beams to limit the movement of a pallet into flue space.<\/li>\n<\/ul>\n<p>Keep in mind that the more flexible options are likely more preferable from a rack safety standpoint. Both nets and straps give as a forklift pushes a pallet too hard into them, which takes pressure off the rack. They may even fail, but that is preferable to warping or damaging a rack&#8217;s steel components.<\/p>\n<h3>More information on rack flue space<\/h3>\n<ul>\n<li><a href=\"https:\/\/www.cisco-eagle.com\/category\/3048\/fire-code-compliance-pallet-racking\">Pallet Racks and Fire Safety Compliance<\/a><\/li>\n<li><a href=\"http:\/\/www.nfpa.org\/codes-and-standards\/all-codes-and-standards\/list-of-codes-and-standards?mode=code&amp;code=231C\" target=\"_blank\" rel=\"noopener noreferrer\"><em>Standard for Rack Storage of Materials<\/em><\/a> from NFPA<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>The National Fire Protection Association (NFPA) has long required that pallet rack flue space remain clear at all times so that any fires can vent upward rather than outward, allowing sprinkler systems to activate faster. This vertical rise also helps slow fire spreading horizontally through a rack system. Flue space compliance is increasingly important to [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[6],"tags":[],"series":[],"class_list":["post-10317","post","type-post","status-publish","format-standard","hentry","category-pallet-rack"],"acf":[],"aioseo_notices":[],"publishpress_future_action":{"enabled":false,"date":"2027-04-18 18:54:16","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/posts\/10317","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/comments?post=10317"}],"version-history":[{"count":38,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/posts\/10317\/revisions"}],"predecessor-version":[{"id":33912,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/posts\/10317\/revisions\/33912"}],"wp:attachment":[{"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/media?parent=10317"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/categories?post=10317"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/tags?post=10317"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/www.cisco-eagle.com\/blog\/wp-json\/wp\/v2\/series?post=10317"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}