{"id":4762,"date":"2026-10-05T10:28:50","date_gmt":"2026-10-05T14:28:50","guid":{"rendered":"https:\/\/metalroofcanada.ca\/?p=4762"},"modified":"2026-10-26T14:18:28","modified_gmt":"2026-10-26T18:18:28","slug":"roof-flashing","status":"publish","type":"post","link":"https:\/\/metalroofcanada.ca\/en\/roof-flashing\/","title":{"rendered":"Roof flashing: why it\u2019s the most important part of your roof"},"content":{"rendered":"<div data-elementor-type=\"wp-post\" data-elementor-id=\"4762\" class=\"elementor elementor-4762\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7e3c376 e-flex e-con-boxed wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-parent\" data-id=\"7e3c376\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t<div class=\"elementor-element elementor-element-7141556 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"7141556\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b1289f0 elementor-widget elementor-widget-text-editor\" data-id=\"b1289f0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Roof flashing is probably the most important part of your roof, and yet the least known. This small metal fitting seals the most vulnerable areas of your roof covering. When it fails, water seeps directly into your home. In fact, it\u2019s the cause of about 90% of roof leaks.<\/span><\/p><p><span style=\"font-weight: 400;\">In this article, we explain the exact role of flashing, the different types available, the signs of wear to watch for and the solutions to prevent<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/ceiling-water-leak-causes-solutions\/\"> <span style=\"font-weight: 400;\">water from leaking through your ceiling<\/span><\/a><span style=\"font-weight: 400;\">. You\u2019ll also learn why a<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/products\/\"> <span style=\"font-weight: 400;\">metal roof<\/span><\/a><span style=\"font-weight: 400;\"> offers a clear advantage when it comes to flashing.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-92c9697 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"92c9697\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a3045d4 elementor-widget elementor-widget-heading\" data-id=\"a3045d4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">What is roof flashing?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d9f43df elementor-widget elementor-widget-text-editor\" data-id=\"d9f43df\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Roof flashing is a watertight fitting installed wherever the roof covering meets a vertical element. It\u2019s found around chimneys, along adjacent walls, around skylights and near plumbing vents.<\/span><\/p><p><span style=\"font-weight: 400;\">Its role is simple but essential: to prevent water from seeping into the joints. Indeed, when rain falls on your roof, it runs downward. Where the roof meets a wall or a chimney, water naturally tries to get into the gap between the two. Flashing therefore blocks this path and redirects the water back onto the roof surface.<\/span><\/p><p><span style=\"font-weight: 400;\">Without flashing, these joints become open doors for water, slush and ice. In Quebec, freeze-thaw cycles make this protection even more critical. Water that seeps in freezes overnight, expands and widens the crack. The problem therefore gets worse quickly from one winter to the next.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-61ed31c e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"61ed31c\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3ab22e7 elementor-widget elementor-widget-heading\" data-id=\"3ab22e7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">The different types of flashing\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0510607 elementor-widget elementor-widget-text-editor\" data-id=\"0510607\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Not all flashing is the same. Each location on the roof requires a type of roof flashing suited to its geometry and exposure.<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Chimney flashing:<\/b><span style=\"font-weight: 400;\"> it surrounds the base of the chimney on all four sides. It\u2019s the most complex to install because it has to fit the shape of the masonry perfectly.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Wall flashing:<\/b><span style=\"font-weight: 400;\"> it seals the joint between the roof and an adjacent vertical wall. It\u2019s often found where a garage meets the house or along a shared wall.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Valley flashing:<\/b><span style=\"font-weight: 400;\"> it protects the roof valleys where two slopes meet. Water converges at these points, which makes them particularly vulnerable.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Vent flashing:<\/b><span style=\"font-weight: 400;\"> it encircles the plumbing pipes and vents that go through the roof. A metal collar with a rubber seal keeps the opening watertight.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Step flashing:<\/b><span style=\"font-weight: 400;\"> it follows the angle between a wall and a sloped roof. Each step overlaps the previous one to direct water downward.<\/span><\/li><\/ul><p>\u00a0<\/p><p><span style=\"font-weight: 400;\">The flashing material also varies depending on the type of roof covering. Thus, on a metal roof, flashing is generally made of steel or aluminum. As a result, it\u2019s compatible with the panels and prevents chemical reactions between different metals.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-053ab61 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"053ab61\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-7a90fc7 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"7a90fc7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c9d5a74 elementor-widget elementor-widget-heading\" data-id=\"c9d5a74\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Signs that flashing is failing\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c2dc8d0 elementor-widget elementor-widget-text-editor\" data-id=\"c2dc8d0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Roof flashing that\u2019s starting to fail sends signals you need to recognize. The sooner you spot them, the less the damage will cost to repair.<\/span><\/p><p><span style=\"font-weight: 400;\">From the outside, look for the following clues during your seasonal inspections. Cracked, crumbling or loose caulking around the joints is the most common sign. Rust marks on the flashing metal also indicate advanced deterioration. Flashing that looks lifted or warped has probably shifted due to frost.<\/span><\/p><p><span style=\"font-weight: 400;\">From the inside, the signs are just as telling. Brownish stains on the ceiling near a chimney or an exterior wall almost always point to failing flashing. A persistent damp smell in the attic often confirms the diagnosis. In addition, wet or mouldy insulation near a wall or a chimney reveals an ongoing leak.<\/span><\/p><p><span style=\"font-weight: 400;\">Don\u2019t wait for an active leak to appear before taking action. Flashing that shows signs of wear today will cause a leak during the next heavy rain or the next snowmelt.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-69699b6 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"69699b6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"960\" height=\"640\" src=\"https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-1024x683.jpg\" class=\"attachment-large size-large wp-image-4659\" alt=\"Ventilateur de toit noir pos\u00e9 sur sa base m\u00e9tallique dans les bardeaux, un solin de toiture qui assure l&#039;\u00e9tanch\u00e9it\u00e9.\" srcset=\"https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-1024x683.jpg 1024w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-300x200.jpg 300w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-768x512.jpg 768w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-1536x1024.jpg 1536w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-18x12.jpg 18w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text-600x400.jpg 600w, https:\/\/metalroofcanada.ca\/wp-content\/uploads\/2026\/10\/Solin-de-toiture-in-text.jpg 1600w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-24ca024 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"24ca024\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-533c660 elementor-widget elementor-widget-heading\" data-id=\"533c660\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Why does flashing fail?\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0af3071 elementor-widget elementor-widget-text-editor\" data-id=\"0af3071\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Several factors explain the gradual deterioration of roof flashing. The Quebec climate is particularly hard on these components.<\/span><\/p><p><span style=\"font-weight: 400;\">Caulking is the first to age. It\u2019s under constant stress: expansion in summer, contraction in winter. After a few years, microcracks appear. Water seeps in, freezes and widens the openings. This cycle repeats until the seal loses all its watertightness.<\/span><\/p><p><span style=\"font-weight: 400;\">Galvanic corrosion is also a problem when incompatible metals come into contact. For example, aluminum flashing fastened to a steel panel creates an electrochemical reaction. This reaction speeds up the corrosion of both materials. That\u2019s why<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/about-2\/\"> <span style=\"font-weight: 400;\">experienced roofers<\/span><\/a><span style=\"font-weight: 400;\"> always use compatible metals.<\/span><\/p><p><span style=\"font-weight: 400;\">A sloppy installation also considerably shortens the flashing\u2019s lifespan. Flashing that\u2019s poorly embedded in the wall, an apron that\u2019s too short or an insufficient overlap create weak points from the start. According to the<\/span><a href=\"https:\/\/www.rbq.gouv.qc.ca\/en\/you-are\/citizen\/renovation-work\/construction-and-renovation-standards\/\"> <span style=\"font-weight: 400;\">R\u00e9gie du b\u00e2timent du Qu\u00e9bec<\/span><\/a><span style=\"font-weight: 400;\">, installation defects are among the most frequent causes of roof-related claims.<\/span><\/p><p><span style=\"font-weight: 400;\">A sloppy installation also considerably shortens the flashing\u2019s lifespan. Flashing that\u2019s poorly embedded in the wall, an apron that\u2019s too short or an insufficient overlap create weak points from the start. According to the <\/span><a href=\"https:\/\/www.rbq.gouv.qc.ca\/en\/you-are\/citizen\/renovation-work\/construction-and-renovation-standards\/\"><span style=\"font-weight: 400;\">R\u00e9gie du b\u00e2timent du Qu\u00e9bec<\/span><\/a><span style=\"font-weight: 400;\">, installation defects are among the most frequent causes of roof-related claims.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-5560b14 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"5560b14\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-628402f elementor-widget elementor-widget-heading\" data-id=\"628402f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Repair or replace flashing?\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-22edd45 elementor-widget elementor-widget-text-editor\" data-id=\"22edd45\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">The decision depends on the extent of the damage. A simple reseal is enough in some cases. In others, a full replacement is necessary.<\/span><\/p><p><span style=\"font-weight: 400;\">If the flashing metal is still in good condition and only the caulking is cracked, a professional reseal solves the problem. The roofer removes the old sealant, cleans the surface and applies a new sealant that\u2019s compatible with your type of roof covering. This work generally costs between $200 and $600.<\/span><\/p><p><span style=\"font-weight: 400;\">On the other hand, if the metal is perforated, rusted or warped, the entire piece must be replaced. Badly corroded flashing will never be watertight again, even with new caulking. Replacement costs more, but it\u2019s the only lasting solution.<\/span><\/p><p><span style=\"font-weight: 400;\">In all cases, hire a qualified professional for this work. Poorly installed flashing causes more problems than it solves. In addition, a non-compliant repair can void your<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/metal-roof-warranty\/\"> <span style=\"font-weight: 400;\">roof warranty<\/span><\/a><span style=\"font-weight: 400;\">. Also, keep the invoices for every job to protect your<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/home-insurance\/\"> <span style=\"font-weight: 400;\">insurance coverage<\/span><\/a><span style=\"font-weight: 400;\">.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-460b0e7 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"460b0e7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-21c2904 elementor-widget elementor-widget-heading\" data-id=\"21c2904\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">The advantage of flashing on a metal roof\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-361aa7c elementor-widget elementor-widget-text-editor\" data-id=\"361aa7c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Flashing on a metal roof offers advantages that asphalt shingles can\u2019t match. The system works in a more integrated and durable way.<\/span><\/p><p><span style=\"font-weight: 400;\">On a <\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/standing-seam-roofing-montreal\/\"><span style=\"font-weight: 400;\">standing seam roof<\/span><\/a><span style=\"font-weight: 400;\">, the flashing is made from the same steel as the panels. This compatibility eliminates the risk of galvanic corrosion. The components age at the same rate, with no weak link in the chain.<\/span><\/p><p><span style=\"font-weight: 400;\">In addition, metal flashing is mechanically fastened rather than simply glued. As a result, it better withstands expansion movements and high winds. Caulking plays a supporting role rather than a primary one in keeping the roof watertight.<\/span><\/p><p><span style=\"font-weight: 400;\">Finally, metal flashing on a steel roof easily lasts 50 years, which is as long as the roof itself. With asphalt shingles, the flashing often outlasts the roof covering, but the caulking must be redone every 5 to 10 years. It\u2019s an expense and a risk that a metal roof almost completely eliminates.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-a9f0c42 e-con-full e-flex wpr-particle-no wpr-jarallax-no wpr-parallax-no wpr-sticky-section-no wpr-column-slider-no wpr-equal-height-no e-con e-child\" data-id=\"a9f0c42\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-2a7ff7a elementor-widget elementor-widget-heading\" data-id=\"2a7ff7a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Conclusion<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e4b04cf elementor-widget elementor-widget-text-editor\" data-id=\"e4b04cf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Roof flashing is small, discreet and often forgotten. However, it\u2019s what protects the most vulnerable points of your roof. When it fails, water gets in and the damage builds up quickly. Inspect your flashing twice a year, in spring and fall. Act at the first signs of wear rather than waiting for a leak.<\/span><\/p><p><span style=\"font-weight: 400;\">Choosing a metal roof with compatible steel flashing eliminates corrosion problems and extends the lifespan of the entire system.<\/span><\/p><p><span style=\"font-weight: 400;\">Is your flashing showing signs of wear?<\/span><a href=\"https:\/\/metalroofcanada.ca\/en\/contact-us-2\/\"> <span style=\"font-weight: 400;\">Contact Metal Roof Canada<\/span><\/a><span style=\"font-weight: 400;\"> for an inspection and a solution tailored to your roof.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Roof flashing is probably the most important part of your roof, and yet the least known. This small metal fitting seals the most vulnerable areas of your roof covering. When it fails, water seeps directly into your home. In fact, it\u2019s the cause of about 90% of roof leaks. In this article, we explain the exact role of flashing, the different types available, the signs of wear to watch for and the solutions to prevent water from leaking through your ceiling. You\u2019ll also learn why a metal roof offers a clear advantage when it comes to flashing. What is roof flashing? Roof flashing is a watertight fitting installed wherever the roof covering meets a vertical element. It\u2019s found around chimneys, along adjacent walls, around skylights and near plumbing vents. Its role is simple but essential: to prevent water from seeping into the joints. Indeed, when rain falls on your roof, it runs downward. Where the roof meets a wall or a chimney, water naturally tries to get into the gap between the two. Flashing therefore blocks this path and redirects the water back onto the roof surface. Without flashing, these joints become open doors for water, slush and ice. In Quebec, freeze-thaw cycles make this protection even more critical. Water that seeps in freezes overnight, expands and widens the crack. The problem therefore gets worse quickly from one winter to the next. The different types of flashing Not all flashing is the same. Each location on the roof requires a type of roof flashing suited to its geometry and exposure. Chimney flashing: it surrounds the base of the chimney on all four sides. It\u2019s the most complex to install because it has to fit the shape of the masonry perfectly. Wall flashing: it seals the joint between the roof and an adjacent vertical wall. It\u2019s often found where a garage meets the house or along a shared wall. Valley flashing: it protects the roof valleys where two slopes meet. Water converges at these points, which makes them particularly vulnerable. Vent flashing: it encircles the plumbing pipes and vents that go through the roof. A metal collar with a rubber seal keeps the opening watertight. Step flashing: it follows the angle between a wall and a sloped roof. Each step overlaps the previous one to direct water downward. \u00a0 The flashing material also varies depending on the type of roof covering. Thus, on a metal roof, flashing is generally made of steel or aluminum. As a result, it\u2019s compatible with the panels and prevents chemical reactions between different metals. Signs that flashing is failing Roof flashing that\u2019s starting to fail sends signals you need to recognize. The sooner you spot them, the less the damage will cost to repair. From the outside, look for the following clues during your seasonal inspections. Cracked, crumbling or loose caulking around the joints is the most common sign. Rust marks on the flashing metal also indicate advanced deterioration. Flashing that looks lifted or warped has probably shifted due to frost. From the inside, the signs are just as telling. Brownish stains on the ceiling near a chimney or an exterior wall almost always point to failing flashing. A persistent damp smell in the attic often confirms the diagnosis. In addition, wet or mouldy insulation near a wall or a chimney reveals an ongoing leak. Don\u2019t wait for an active leak to appear before taking action. Flashing that shows signs of wear today will cause a leak during the next heavy rain or the next snowmelt. Why does flashing fail? Several factors explain the gradual deterioration of roof flashing. The Quebec climate is particularly hard on these components. Caulking is the first to age. It\u2019s under constant stress: expansion in summer, contraction in winter. After a few years, microcracks appear. Water seeps in, freezes and widens the openings. This cycle repeats until the seal loses all its watertightness. Galvanic corrosion is also a problem when incompatible metals come into contact. For example, aluminum flashing fastened to a steel panel creates an electrochemical reaction. This reaction speeds up the corrosion of both materials. That\u2019s why experienced roofers always use compatible metals. A sloppy installation also considerably shortens the flashing\u2019s lifespan. Flashing that\u2019s poorly embedded in the wall, an apron that\u2019s too short or an insufficient overlap create weak points from the start. According to the R\u00e9gie du b\u00e2timent du Qu\u00e9bec, installation defects are among the most frequent causes of roof-related claims. A sloppy installation also considerably shortens the flashing\u2019s lifespan. Flashing that\u2019s poorly embedded in the wall, an apron that\u2019s too short or an insufficient overlap create weak points from the start. According to the R\u00e9gie du b\u00e2timent du Qu\u00e9bec, installation defects are among the most frequent causes of roof-related claims. Repair or replace flashing? The decision depends on the extent of the damage. A simple reseal is enough in some cases. In others, a full replacement is necessary. If the flashing metal is still in good condition and only the caulking is cracked, a professional reseal solves the problem. The roofer removes the old sealant, cleans the surface and applies a new sealant that\u2019s compatible with your type of roof covering. This work generally costs between $200 and $600. On the other hand, if the metal is perforated, rusted or warped, the entire piece must be replaced. Badly corroded flashing will never be watertight again, even with new caulking. Replacement costs more, but it\u2019s the only lasting solution. In all cases, hire a qualified professional for this work. Poorly installed flashing causes more problems than it solves. In addition, a non-compliant repair can void your roof warranty. Also, keep the invoices for every job to protect your insurance coverage. The advantage of flashing on a metal roof Flashing on a metal roof offers advantages that asphalt shingles can\u2019t match. The system works in a more integrated and durable way. On a standing seam roof, the flashing is made from the same steel as the panels.<\/p>","protected":false},"author":1,"featured_media":4658,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[87],"tags":[],"class_list":["post-4762","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-non-classe-fr-en"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Roof flashing: role, problems and solutions<\/title>\n<meta name=\"description\" content=\"Roof flashing causes about 90% of roof leaks. 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