Architectural surface innovation using Venetian and lime-based finishes

Abstract

Venetian and lime-based finishes are experiencing renewed interest as breathable, low-carbon alternatives to polymer and cement-based wall coatings, yet quantitative, side-by-side comparisons of their engineering behaviour remain scarce. This study examines five representative systems; Grassello Veneziano, Marmorino, Tadelakt, traditional limewash, and a pozzolan-modified lime plaster through a unified experimental programme that links formulation and application parameters to measured performance. Specimens were prepared on standardised mineral substrates under controlled curing (20 °C, 60% relative humidity) and characterised for bulk density, surface microhardness, flexural and adhesion strength, dynamic elastic modulus, water-vapour resistance, capillary absorption, carbonation depth over ninety days, specular gloss, and surface roughness. A normalised multi-criteria framework was then used to synthesise durability, breathability, aesthetic finish, workability, and CO₂ uptake into a single comparative profile. Results show a clear performance gradient: Tadelakt achieved the highest gloss and the lowest capillary absorption owing to saponification-driven pore sealing, whereas limewash offered the greatest breathability but the weakest mechanical response. Pozzolan modification produced the strongest, most durable, and most CO₂-efficient system without compromising vapour permeability, while Grassello Veneziano balanced aesthetics and mechanical integrity. The findings provide a practical, evidence-based basis for selecting and engineering Venetian and lime finishes for contemporary and heritage architectural surfaces.