{"product_id":"grp-mushroom-roof-vent-75mm","title":"GRP Mushroom Roof Vent – 75mm","description":"\u003ch3\u003eMoisture Relief \u0026amp; Supplementary Ventilation for GRP Flat Roofs\u003c\/h3\u003e\n\n\u003cp\u003eThis \u003cstrong\u003eGRP Mushroom Roof Vent (75mm)\u003c\/strong\u003e is designed to provide controlled vertical ventilation through a fibreglass flat roof system.\u003c\/p\u003e\n\n\u003cp\u003eCommonly installed in refurbishment and overlay projects, it helps relieve trapped moisture vapour and reduce pressure build-up within the roof structure.\u003c\/p\u003e\n\n\u003cp\u003eSuitable for use with most GRP flat roofing systems.\u003c\/p\u003e\n\n\u003cdetails style=\"margin-bottom:12px; border:1px solid #333; border-radius:10px; background:#1a1a1a; overflow:hidden;\"\u003e\n  \u003csummary style=\"cursor:pointer; font-weight:700; padding:16px 48px 16px 16px; font-size:18px; position:relative;\"\u003e\n    What It’s Used For\n    \u003cspan style=\"position:absolute; right:16px; top:50%; transform:translateY(-50%);\"\u003e▸\u003c\/span\u003e\n  \u003c\/summary\u003e\n  \u003cdiv style=\"padding:16px; border-top:1px solid #333;\"\u003e\n    \u003cul\u003e\n      \u003cli\u003eReleasing trapped moisture in existing roof decks\u003c\/li\u003e\n      \u003cli\u003eSupporting ventilation in cold roof constructions\u003c\/li\u003e\n      \u003cli\u003eReducing risk of vapour pressure build-up in overlay systems\u003c\/li\u003e\n    \u003c\/ul\u003e\n    \u003cp\u003eOften installed where full strip-out of the existing roof is not being undertaken.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"margin-bottom:12px; border:1px solid #333; border-radius:10px; background:#1a1a1a; overflow:hidden;\"\u003e\n  \u003csummary style=\"cursor:pointer; font-weight:700; padding:16px 48px 16px 16px; font-size:18px; position:relative;\"\u003e\n    Why It Matters\n    \u003cspan style=\"position:absolute; right:16px; top:50%; transform:translateY(-50%);\"\u003e▸\u003c\/span\u003e\n  \u003c\/summary\u003e\n  \u003cdiv style=\"padding:16px; border-top:1px solid #333;\"\u003e\n    \u003cp\u003eTrapped moisture beneath a new GRP membrane can lead to pressure build-up and blistering over time. A mushroom vent provides a controlled outlet for vapour, helping stabilise the roof structure.\u003c\/p\u003e\n\n    \u003cp\u003eIt provides vertical ventilation only and is not a substitute for designed cross flow ventilation where required by building regulations.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"margin-bottom:12px; border:1px solid #333; border-radius:10px; background:#1a1a1a; overflow:hidden;\"\u003e\n  \u003csummary style=\"cursor:pointer; font-weight:700; padding:16px 48px 16px 16px; font-size:18px; position:relative;\"\u003e\n    Installation Overview\n    \u003cspan style=\"position:absolute; right:16px; top:50%; transform:translateY(-50%);\"\u003e▸\u003c\/span\u003e\n  \u003c\/summary\u003e\n  \u003cdiv style=\"padding:16px; border-top:1px solid #333;\"\u003e\n    \u003cul\u003e\n      \u003cli\u003eCore drill the deck to suit the vent stem.\u003c\/li\u003e\n      \u003cli\u003ePosition the vent so the stem aligns with the hole and the flange sits flat on the surface.\u003c\/li\u003e\n      \u003cli\u003eMechanically fix the flange if required.\u003c\/li\u003e\n      \u003cli\u003eLaminate the flange into the GRP base coat using CSM reinforcement.\u003c\/li\u003e\n      \u003cli\u003eConsolidate thoroughly and apply top coat as part of the system.\u003c\/li\u003e\n    \u003c\/ul\u003e\n    \u003cp\u003eEnsure roof falls direct water away from the vent base.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"margin-bottom:12px; border:1px solid #333; border-radius:10px; background:#1a1a1a; overflow:hidden;\"\u003e\n  \u003csummary style=\"cursor:pointer; font-weight:700; padding:16px 48px 16px 16px; font-size:18px; position:relative;\"\u003e\n    Technical Specification\n    \u003cspan style=\"position:absolute; right:16px; top:50%; transform:translateY(-50%);\"\u003e▸\u003c\/span\u003e\n  \u003c\/summary\u003e\n  \u003cdiv style=\"padding:16px; border-top:1px solid #333;\"\u003e\n    \u003cul\u003e\n      \u003cli\u003eDiameter: 75mm\u003c\/li\u003e\n      \u003cli\u003eType: Mushroom-style roof vent\u003c\/li\u003e\n      \u003cli\u003eColour: Grey\u003c\/li\u003e\n      \u003cli\u003eApplication: GRP roofing systems\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"margin-bottom:12px; border:1px solid #333; border-radius:10px; background:#1a1a1a; overflow:hidden;\"\u003e\n  \u003csummary style=\"cursor:pointer; font-weight:700; padding:16px 48px 16px 16px; font-size:18px; position:relative;\"\u003e\n    Summary\n    \u003cspan style=\"position:absolute; right:16px; top:50%; transform:translateY(-50%);\"\u003e▸\u003c\/span\u003e\n  \u003c\/summary\u003e\n  \u003cdiv style=\"padding:16px; border-top:1px solid #333;\"\u003e\n    \u003cp\u003eThe GRP Mushroom Roof Vent (75mm) provides controlled vapour release within fibreglass roofing systems, helping manage moisture in refurbishment and overlay applications.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/details\u003e","brand":"The Flat Roofing Shop","offers":[{"title":"Default Title","offer_id":56696760107339,"sku":"GRP-ROOFVENT-075","price":40.32,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0997\/4054\/9451\/files\/grp-breather-vent-4.jpg?v=1774177191","url":"https:\/\/theflatroofingshop.co.uk\/products\/grp-mushroom-roof-vent-75mm","provider":"The Flat Roofing Shop","version":"1.0","type":"link"}