Category Archives: General Installation Guidelines

Lime Paints User Recomendations – Guide

Vibrant and beautiful, the St Astier lime paint range is the perfect compliment to lime plaster, render and harling, suitable for most backgrounds. Can be applied to gypsum plasters, lining paper, cement and lime backgrounds, bricks, blocks and untreated timber. Mixing: The general ratio is 1 volume of powder to 2 volumes of clean water. […]

Render on Wooden Lath – Guide

External rendering on wooden lath using St. Astier products. Timber framed buildings, historic or new construction have a tendency to greater movement than solid masonry construction, particularly new green timber construction.To achieve the maximum degree of tolerance to movement in a render on wooden lath, a low strength mortar of exceptional modulus of elasticity should be […]

Render on Metal Lath – Guide

External Plastering (Rendering on Metal Lath Using St. Astier Products) The main difficulty in working on lath is ensuring the lath is suitable for the job. Metal laths come in a wide variety of types and designs, some of which have specific functions and are not suitable for a broad range of rendering applications. It […]

Sands for NHL Mortars – Guide

Choosing the correct sand when making a mortar is of extreme importance. Sands should be clean and uncontaminated by clay/silt. These occur in the range from #300 and below and the most effective method to establish their presence is the wet sieve analysis. Normal dry sieve analysis does not accurately reveal the presence of clay […]

NHL Renders – Guide

NHL Renders General information Sands for renders Background preparation Two coat work Three coat work Protection Good working practices Render Diagnostics Some recommended mixes   Other General Guidelines documents: Render on cob Render on wooden lath Render on metal lath Render on blocks Rendering with a spray gun The correct specification for any render should […]

Pointing with NHL – Guide

Pointing with NHL Understanding mortars Choosing mortars Resistance to saltsProtection and working practices Repointing: preparation, application, finishing Repointing dense masonry Repointing ashlar masonry NHL Mortar mixes April 2001       Re-Pointing Masonry Walls: Brick, Blocks and Natural Stone. Understanding mortars.Before deciding to re-point a basic understanding of the function of mortars is required. Mortar is […]

NHL Render – Guide

Background Prepare background Re-point and dub out as necessary with compatible mortar. Stipple Coat Cast or sprayed on only Must be used on poor suction, dense / smooth surfaces. Leave as Cast Cure 2 – 4 days First Coat Cast, spray or lay on. Well-keyed background. Control suction. Leave Keyed Cure 4 – 7 days […]

Plaster on Blocks – Guide

External Plastering (Rendering) On Concrete Masonry Units To obtain the highest vapor permeability a block construction should be built with an NHL mortar. Sands: always use well graded coarse sand (#5 to #200) unless indicated. NHL mortar will not alter the color of the sand. See also Sands for NHL Mortar. Main recommendations: make sure that […]