{"id":1008,"date":"2026-08-10T09:24:00","date_gmt":"2026-08-10T09:24:00","guid":{"rendered":"https:\/\/pressure.mobi\/blog\/?p=1008"},"modified":"2026-08-10T09:24:00","modified_gmt":"2026-08-10T09:24:00","slug":"moss-vs-lichen-roof","status":"publish","type":"post","link":"https:\/\/pressure.mobi\/blog\/moss-vs-lichen-roof\/","title":{"rendered":"Moss, lichen or algae? How to tell what is on your roof"},"content":{"rendered":"<p>Black streaks, green cushions and grey-white crust are three different organisms with three different implications for your shingles. All three are treatable, but the right expectations for <a href=\"\/roof-cleaning\/\">roof cleaning treatment<\/a> depend on which one you have.<\/p>\n<h2>Algae: the streaks<\/h2>\n<p>Gloeocapsa magma shows as dark vertical streaking, usually starting near the ridge and widening downward. It is the most common, the most cosmetic in the short term, and the most responsive to treatment \u2014 most of the discolouration lifts as the solution works.<\/p>\n<p>Left alone it degrades the shingle slowly, holding moisture and consuming limestone filler. Treat it and the roof typically stays clear for years.<\/p>\n<h2>Moss: the cushions<\/h2>\n<p>Moss grows as green mounds along shingle edges and in the shaded gaps between courses. It is the most structurally urgent of the three: the root-like rhizoids work under shingle edges and lift them, and the cushions hold water against the roof like a sponge.<\/p>\n<p>Moss dies quickly once treated, but it releases gradually \u2014 expect the cushions to brown, shrink and shed over following weeks of weather. Nobody should be scraping or blasting moss off shingles; that removes granules and lifts edges.<\/p>\n<h2>Lichen: the crust<\/h2>\n<p>Lichen \u2014 grey-white or pale green discs bonded tightly to the surface \u2014 is the stubborn one. It anchors into the granule layer itself, and mechanically removing it takes granules with it.<\/p>\n<p>Treatment kills it, but dead lichen releases slowly, over weeks to months, and heavy colonisation can leave shadowing. An honest contractor tells you that before starting rather than promising an instant spotless roof.<\/p>\n<p><em>Photograph what is growing up there and we will identify it, tell you how urgent it is, and quote the treatment.<\/em> <a href=\"\/roof-cleaning\/\">Read more about roof cleaning treatment &rarr;<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Black streaks, green cushions and grey-white crust are three different organisms with three different implications for your shingles. All three are treatable, but the right expectations for roof cleaning treatment depend on which one you have.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"pagelayer_contact_templates":[],"_pagelayer_content":"","footnotes":""},"categories":[15],"tags":[],"class_list":["post-1008","post","type-post","status-publish","format-standard","hentry","category-roof-cleaning"],"_links":{"self":[{"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/posts\/1008","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/comments?post=1008"}],"version-history":[{"count":1,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/posts\/1008\/revisions"}],"predecessor-version":[{"id":1103,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/posts\/1008\/revisions\/1103"}],"wp:attachment":[{"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/media?parent=1008"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/categories?post=1008"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pressure.mobi\/blog\/wp-json\/wp\/v2\/tags?post=1008"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}