Roundtower Board RenderRoundtower Board Render Roundtower Board Render is a fibre reinforced, breathable lime render designed for use over insulation boards within both internal and external wall insulation systems. Formulated using Natural Hydraulic Lime and carefully graded aggregates, it provides a durable, vapour open basecoat for wood fibre, cork, wood wool, and other breathable insulation boards. Its combination of strength, flexibility, and vapour permeability makes

and install

Featuring a central internal shank

Roundtower Tanking Render is designed to provide resistance to liquid water while maintaining vapour permeability

and plasters

Why Use Isovit Lightflex

4–6m² per litre (varies with substrate and application)

the board is highly vapour open and moisture regulating

Roundtower NHL 5 is a high-strength Natural Hydraulic Lime (NHL) designed for demanding applications where increased durability

External wall insulation

Suitable for a wide range of substrates

timber frame conservation

and where a more robust sawn lath is preferred over softwood