{"product_id":"cm20-cavity-drain-membrane-for-basements-2m-x-20m-1","title":"CM20 Cavity Drain Membrane for Basements 2m x 20m","description":"\u003ch2 data-section-id=\"896bty\" data-start=\"0\" data-end=\"89\"\u003eClever Shield CM20 Cavity Drain Membrane – High Capacity Type C Basement Waterproofing\u003c\/h2\u003e\n\u003cp data-start=\"91\" data-end=\"284\"\u003eTake control of heavy water ingress with the \u003cstrong data-start=\"136\" data-end=\"180\"\u003eClever Shield CM20 Cavity Drain Membrane\u003c\/strong\u003e — a \u003cstrong data-start=\"185\" data-end=\"232\"\u003ehigh-capacity Type C waterproofing membrane\u003c\/strong\u003e engineered for demanding below-ground environments.\u003c\/p\u003e\n\u003cp data-start=\"286\" data-end=\"533\"\u003eWith a \u003cstrong data-start=\"293\" data-end=\"348\"\u003e20mm stud profile and superior drainage performance\u003c\/strong\u003e, CM20 delivers reliable protection for basements, floors, and structures exposed to high groundwater levels—helping you achieve a \u003cstrong data-start=\"479\" data-end=\"511\"\u003eGrade 3 dry, habitable space\u003c\/strong\u003e in line with BS 8102.\u003c\/p\u003e\n\u003chr data-start=\"535\" data-end=\"538\"\u003e\n\u003ch3 data-section-id=\"zbz2fq\" data-start=\"540\" data-end=\"581\"\u003eMaximum Drainage. Maximum Protection.\u003c\/h3\u003e\n\u003cul data-start=\"583\" data-end=\"1210\"\u003e\n\u003cli data-section-id=\"yngh88\" data-start=\"583\" data-end=\"654\"\u003e\n\u003cstrong data-start=\"585\" data-end=\"616\"\u003eType C Waterproofing System\u003c\/strong\u003e – Fully compliant with BS 8102:2009\u003c\/li\u003e\n\u003cli data-section-id=\"138hxpx\" data-start=\"655\" data-end=\"728\"\u003e\n\u003cstrong data-start=\"657\" data-end=\"692\"\u003eHigh Drainage Capacity (14L\/m²)\u003c\/strong\u003e – One of the highest in its class\u003c\/li\u003e\n\u003cli data-section-id=\"ammp5i\" data-start=\"729\" data-end=\"812\"\u003e\n\u003cstrong data-start=\"731\" data-end=\"758\"\u003eBBA Certified (18\/5595)\u003c\/strong\u003e – Independently tested for performance \u0026amp; durability\u003c\/li\u003e\n\u003cli data-section-id=\"18rf9ae\" data-start=\"813\" data-end=\"899\"\u003e\n\u003cstrong data-start=\"815\" data-end=\"846\"\u003eIdeal for High Water Tables\u003c\/strong\u003e – Designed for challenging below-ground conditions\u003c\/li\u003e\n\u003cli data-section-id=\"q3yht7\" data-start=\"900\" data-end=\"973\"\u003e\n\u003cstrong data-start=\"902\" data-end=\"923\"\u003eFast Installation\u003c\/strong\u003e – Lightweight rolls for quick floor application\u003c\/li\u003e\n\u003cli data-section-id=\"tfmx9i\" data-start=\"974\" data-end=\"1049\"\u003e\n\u003cstrong data-start=\"976\" data-end=\"1005\"\u003eMinimal Structural Impact\u003c\/strong\u003e – No major prep or invasive work required\u003c\/li\u003e\n\u003cli data-section-id=\"48e0wo\" data-start=\"1050\" data-end=\"1135\"\u003e\n\u003cstrong data-start=\"1052\" data-end=\"1076\"\u003eLong-Term Durability\u003c\/strong\u003e – Resistant to water, salts, roots \u0026amp; structural movement\u003c\/li\u003e\n\u003cli data-section-id=\"1idpm2w\" data-start=\"1136\" data-end=\"1210\"\u003e\n\u003cstrong data-start=\"1138\" data-end=\"1163\"\u003eTemperature Resistant\u003c\/strong\u003e – Performs in both hot and cold environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1212\" data-end=\"1215\"\u003e\n\u003ch3 data-section-id=\"8cavt7\" data-start=\"1217\" data-end=\"1263\"\u003eBuilt for Demanding Waterproofing Projects\u003c\/h3\u003e\n\u003cp data-start=\"1265\" data-end=\"1460\"\u003eThe CM20 membrane creates a \u003cstrong data-start=\"1293\" data-end=\"1324\"\u003ehigh-capacity drainage void\u003c\/strong\u003e, allowing water to flow freely into \u003cstrong data-start=\"1361\" data-end=\"1404\"\u003edrainage channels and sump pump systems\u003c\/strong\u003e, preventing pressure build-up against floors and walls.\u003c\/p\u003e\n\u003cp data-start=\"1462\" data-end=\"1474\"\u003ePerfect for:\u003c\/p\u003e\n\u003cul data-start=\"1475\" data-end=\"1704\"\u003e\n\u003cli data-section-id=\"1dk369s\" data-start=\"1475\" data-end=\"1512\"\u003eBasement and cellar waterproofing\u003c\/li\u003e\n\u003cli data-section-id=\"ww3h2v\" data-start=\"1513\" data-end=\"1544\"\u003eFloor waterproofing systems\u003c\/li\u003e\n\u003cli data-section-id=\"g8mux7\" data-start=\"1545\" data-end=\"1578\"\u003eHigh water table environments\u003c\/li\u003e\n\u003cli data-section-id=\"1h6efbv\" data-start=\"1579\" data-end=\"1623\"\u003eTunnels, vaults \u0026amp; underground structures\u003c\/li\u003e\n\u003cli data-section-id=\"1idsdgj\" data-start=\"1624\" data-end=\"1665\"\u003eRadon barrier compliant installations\u003c\/li\u003e\n\u003cli data-section-id=\"1ols01c\" data-start=\"1666\" data-end=\"1704\"\u003eNew build \u0026amp; retrofit waterproofing\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1706\" data-end=\"1709\"\u003e\n\u003ch3 data-section-id=\"1dqbs77\" data-start=\"1711\" data-end=\"1737\"\u003eProduct Specifications\u003c\/h3\u003e\n\u003cul data-start=\"1739\" data-end=\"2005\"\u003e\n\u003cli data-section-id=\"fsnyl5\" data-start=\"1739\" data-end=\"1764\"\u003e\n\u003cstrong data-start=\"1741\" data-end=\"1757\"\u003eStud Height:\u003c\/strong\u003e 20mm\u003c\/li\u003e\n\u003cli data-section-id=\"1dqjlzb\" data-start=\"1765\" data-end=\"1806\"\u003e\n\u003cstrong data-start=\"1767\" data-end=\"1791\"\u003eWater Void Capacity:\u003c\/strong\u003e 14 litres\/m²\u003c\/li\u003e\n\u003cli data-section-id=\"1mflrqq\" data-start=\"1807\" data-end=\"1857\"\u003e\n\u003cstrong data-start=\"1809\" data-end=\"1822\"\u003eMaterial:\u003c\/strong\u003e High-density polyethylene (HDPE)\u003c\/li\u003e\n\u003cli data-section-id=\"19pelyc\" data-start=\"1858\" data-end=\"1954\"\u003e\n\u003cstrong data-start=\"1860\" data-end=\"1875\"\u003eRoll Sizes:\u003c\/strong\u003e\n\u003cul data-start=\"1880\" data-end=\"1954\"\u003e\n\u003cli data-section-id=\"1t2v9sk\" data-start=\"1880\" data-end=\"1908\"\u003e2m x 20m (40m² coverage)\u003c\/li\u003e\n\u003cli data-section-id=\"3dddqh\" data-start=\"1911\" data-end=\"1954\"\u003e2m x 10m (20m² coverage | approx. 20kg)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"91jcrb\" data-start=\"1955\" data-end=\"2005\"\u003e\n\u003cstrong data-start=\"1957\" data-end=\"1973\"\u003eApplication:\u003c\/strong\u003e Floors \u0026amp; walls (below ground)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"2007\" data-end=\"2010\"\u003e\n\u003ch3 data-section-id=\"1uiyn5s\" data-start=\"2012\" data-end=\"2059\"\u003eDesigned for Complete Waterproofing Systems\u003c\/h3\u003e\n\u003cp data-start=\"2061\" data-end=\"2140\"\u003eFor best results, install CM20 as part of a full cavity drain system including:\u003c\/p\u003e\n\u003cul data-start=\"2142\" data-end=\"2276\"\u003e\n\u003cli data-section-id=\"1szzmfi\" data-start=\"2142\" data-end=\"2173\"\u003ePerimeter drainage channels\u003c\/li\u003e\n\u003cli data-section-id=\"m14vmi\" data-start=\"2174\" data-end=\"2206\"\u003eSump chambers \u0026amp; pump systems\u003c\/li\u003e\n\u003cli data-section-id=\"1l0o7nw\" data-start=\"2207\" data-end=\"2239\"\u003eFixing plugs \u0026amp; sealing tapes\u003c\/li\u003e\n\u003cli data-section-id=\"1qgsed4\" data-start=\"2240\" data-end=\"2276\"\u003eFloor finishes or screed systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2278\" data-end=\"2377\"\u003eThis ensures a \u003cstrong data-start=\"2293\" data-end=\"2343\"\u003emaintainable, long-term waterproofing solution\u003c\/strong\u003e that meets UK building standards.\u003c\/p\u003e\n\u003chr data-start=\"2379\" data-end=\"2382\"\u003e\n\u003ch3 data-section-id=\"19prnub\" data-start=\"2384\" data-end=\"2423\"\u003eIdeal for Converting Problem Spaces\u003c\/h3\u003e\n\u003cp data-start=\"2425\" data-end=\"2593\"\u003eWhether you're tackling a flooded basement or planning a full conversion, CM20 helps you create \u003cstrong data-start=\"2521\" data-end=\"2561\"\u003edry, usable living or storage spaces\u003c\/strong\u003e—even in high-risk environments.\u003c\/p\u003e\n\u003chr data-start=\"2595\" data-end=\"2598\"\u003e\n\u003ch2 data-section-id=\"1r8frcv\" data-start=\"2600\" data-end=\"2629\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3 data-section-id=\"112bh4c\" data-start=\"2631\" data-end=\"2674\"\u003eWhat is a Type C cavity drain membrane?\u003c\/h3\u003e\n\u003cp data-start=\"2675\" data-end=\"2806\"\u003eA Type C membrane manages water ingress by allowing it to enter a controlled cavity and safely drain away, rather than blocking it.\u003c\/p\u003e\n\u003ch3 data-section-id=\"s7iy4e\" data-start=\"2808\" data-end=\"2839\"\u003eWhy choose a 20mm membrane?\u003c\/h3\u003e\n\u003cp data-start=\"2840\" data-end=\"2964\"\u003eA 20mm stud depth provides \u003cstrong data-start=\"2867\" data-end=\"2896\"\u003egreater drainage capacity\u003c\/strong\u003e, making it ideal for areas with \u003cstrong data-start=\"2929\" data-end=\"2963\"\u003ehigh water ingress or pressure\u003c\/strong\u003e.\u003c\/p\u003e\n\u003ch3 data-section-id=\"ii4q8t\" data-start=\"2966\" data-end=\"3006\"\u003eIs Clever Shield CM20 BBA certified?\u003c\/h3\u003e\n\u003cp data-start=\"3007\" data-end=\"3107\"\u003eYes, CM20 is fully \u003cstrong data-start=\"3026\" data-end=\"3053\"\u003eBBA certified (18\/5595)\u003c\/strong\u003e, ensuring compliance with UK waterproofing standards.\u003c\/p\u003e\n\u003ch3 data-section-id=\"1uw5c9l\" data-start=\"3109\" data-end=\"3140\"\u003eCan this be used on floors?\u003c\/h3\u003e\n\u003cp data-start=\"3141\" data-end=\"3252\"\u003eYes, CM20 is specifically designed for \u003cstrong data-start=\"3180\" data-end=\"3202\"\u003efloor applications\u003c\/strong\u003e and can also be used on walls in high-risk areas.\u003c\/p\u003e\n\u003ch3 data-section-id=\"5mrqs8\" data-start=\"3254\" data-end=\"3298\"\u003eIs it suitable for basement conversions?\u003c\/h3\u003e\n\u003cp data-start=\"3299\" data-end=\"3405\"\u003eAbsolutely. It’s ideal for creating \u003cstrong data-start=\"3335\" data-end=\"3369\"\u003edry, habitable basement spaces\u003c\/strong\u003e when used as part of a full system.\u003c\/p\u003e\n\u003ch5\u003eBBA\u003cbr\u003e\n\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/wykamol.com\/uploads\/files\/CM20_BBA.pdf\" title=\"Cm20 bba\" aria-label=\"Visit a webpage about Cm20 bba\"\u003eCM20 BBA\u003c\/a\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/wykamol.com\/uploads\/files\/BBA-Certification-Wykamol-CM20-Cavity-Drain-Membrane-18-5595.pdf\" title=\"Bba certification clever shield cm20 cavity drain membrane 18 5595\" aria-label=\"Visit a webpage about Bba certification clever shield cm20 cavity drain membrane 18 5595\"\u003eBBA Certification Clever Shield CM20 Cavity Drain Membrane 18 5595\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003ePerformance\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/wykamol.com\/uploads\/files\/Declaration-of-Performance-CM20-Cavity-Drain-Membrane-WPDOP05-2019-08.pdf\" title=\"Declaration of performance cm20 cavity drain membrane wpdop05 2019 08\" aria-label=\"Visit a webpage about Declaration of performance cm20 cavity drain membrane wpdop05 2019 08\"\u003eDeclaration Of Performance CM20 Cavity Drain Membrane WPDOP05 2019 08\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003eTDS\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/wykamol.com\/uploads\/files\/CM20-CDM-DataSheet.pdf\" title=\"Cm20 cdm data sheet\" aria-label=\"Visit a webpage about Cm20 cdm data sheet\"\u003e CM20 CDM Data Sheet\u003c\/a\u003e\u003cbr\u003e\u003cbr\u003e \u003c\/p\u003e\n\u003ch2\u003e \u003c\/h2\u003e\n\u003cp\u003e\u003cbr\u003e \u003c\/p\u003e","brand":"Clever Shield","offers":[{"title":"CM20 2m x 10m","offer_id":50876714451104,"sku":null,"price":129.01,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0321\/5320\/6920\/files\/cm20-cavity-drain-membrane-type-c-waterproofing-solution-289.webp?v=1765891032","url":"https:\/\/clevershieldcoatings.co.uk\/products\/cm20-cavity-drain-membrane-for-basements-2m-x-20m-1","provider":"Clever Shield - Asset Protection","version":"1.0","type":"link"}