{"product_id":"roundtower-trass-mortar-render-premix","title":"Roundtower Trass Mortar \u0026 Render","description":"\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eRoundtower Heritage Trass Coarse is a specialist, ready-mixed lime mortar and render designed for the repair, restoration and conservation of traditional stone and brick masonry. Formulated with lime and natural Trass pozzolan, this coarse-textured mortar combines excellent vapour permeability with low capillary water absorption, making it particularly suitable for older buildings where moisture management is essential.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDeveloped to work sympathetically with traditional masonry, Roundtower Heritage Trass Coarse provides a breathable alternative to dense cement-based mortars and renders, helping walls release moisture through evaporation while reducing unnecessary restrictions to vapour movement.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eIdeal Basecoat for \u003ca href=\"https:\/\/www.roundtowerlime.com\/products\/roundtower-supertherm\"\u003eRoundtower SuperTherm Insulating Lime Plaster\u003c\/a\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eOne of the key applications of Roundtower Heritage Trass Coarse is as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003epreparatory basecoat beneath Roundtower SuperTherm Insulating Lime Plaster\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, particularly on older masonry walls affected by soluble salts.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTraditional stone and brick walls can contain salts resulting from historic moisture ingress, ground moisture or previous building treatments. As moisture evaporates, these salts can crystallise within plaster layers, potentially causing surface deterioration, powdering and loss of adhesion.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWhere appropriate following an assessment of the masonry and salt contamination, Roundtower Heritage Trass Coarse can be used as a sacrificial or preparatory lime basecoat before applying Roundtower SuperTherm, helping provide a compatible background for the insulation system.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIts highly breathable formulation also makes it suitable for conservation projects where maintaining the natural moisture movement of traditional masonry is a priority.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eFeatures \u0026amp; Benefits\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul data-spread=\"false\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHighly vapour permeable\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – supports moisture evaporation from traditional masonry\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLow capillary water absorption\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – helps limit liquid water uptake while maintaining breathability\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSuitable for salt-affected masonry\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – can be considered as a preparatory basecoat where soluble salts are present, subject to project assessment\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCompatible with traditional stone and brick\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – particularly suited to heritage restoration and conservation work\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eIdeal beneath Roundtower SuperTherm\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – provides a coarse lime-based background for subsequent insulating plaster applications, subject to system compatibility\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eNatural Trass pozzolan\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – contributes to the specialist performance characteristics of the mortar\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSuitable for internal and external applications\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – where the mortar is appropriate for the substrate and exposure conditions\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eReady-mixed formulation\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – promotes consistent material proportions and reduces onsite mixing variations\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCoarse aggregate grading\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – suitable for preparatory coats, backing coats and general lime rendering\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan\u003eProduct Specifications\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul data-spread=\"false\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eProduct Type:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Breathable Lime Mortar \u0026amp; Render\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBinder:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Lime with Natural Rhine Trass Pozzolan\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAggregate:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Coarse graded natural sand, up to 5mm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eApplication:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Internal and External\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePrimary Uses:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Basecoats, Render Backing Coats, Traditional Masonry Repairs\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSpecialist Application:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Preparatory coat beneath Roundtower SuperTherm on appropriately assessed salt-affected masonry\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBag Size:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 25kg\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eApproximate Yield:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 14.5 litres per bag\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eApproximate Coverage:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 1.5m² per bag at 10mm thickness\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan\u003eSuitable Applications\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eRoundtower Heritage Trass Coarse is particularly suited to the restoration of older stone cottages, historic brick buildings, period properties and traditional solid masonry walls where breathable materials are required.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIt can also form part of a carefully specified internal insulation system using Roundtower SuperTherm Insulating Lime Plaster, helping prepare uneven or salt-affected masonry backgrounds before insulation is applied.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor best results, existing sources of moisture ingress should be identified and addressed before application. Where significant salt contamination is present, the suitability and expected service life of the basecoat should be assessed before installing additional plaster layers.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eRoundtower Heritage Trass Coarse offers a practical, conservation-focused solution for traditional masonry repairs and breathable lime plaster systems, combining compatibility with historic building materials and effective moisture management.\u003c\/span\u003e\u003c\/p\u003e","brand":"Roundtower Lime","offers":[{"title":"Default Title","offer_id":47433103737005,"sku":null,"price":26.75,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0648\/7297\/2461\/files\/RoundtowerTrassRender.jpg?v=1792932377","url":"https:\/\/www.roundtowerlime.com\/products\/roundtower-trass-mortar-render-premix","provider":"Roundtower Lime Ireland","version":"1.0","type":"link"}