Gwynne Anthony 2020

ART506 Dissertation 2019. Anthony Gwynne . 111 haired base coat External render Hydraulic Lime NHL 3.5 2 x 9mm Hydraulic Lime NHL 3.5 / NHL2 1 x 6mm Key: Fat Lime = non hydraulic lime; NHL 1 or 2: Natural hydraulic lime containing up to 12% clay (slow set); NHL 3.5: Natural hydraulic lime containing 12-18% clay (moderate set); NHL 5: Natural hydraulic lime containing up to 25% clay (faster set). o Dub out uneven surfaces prior to applying first coat. 1 May require more coats due to waviness of bales * Insulation blocks have very high suction, be careful to maintain moisture content in render/plaster mixes in accordance with manufacturer's details. **Lime Hemp plaster is preferred in these situations applied in accordance with lime specialist’s details (available from Ty-Mawr at: www.lime.org.uk ). Notes: Above table contains suggested mortar mixes only and the actual mortar mix, build up ant thickness of coats is to be specified by a suitably qualified and experienced conservation specialist- suitable for the type of wall material and degree of exposure. Exposed elevations may require additional coats Guidance Table 3.1: Hemp lime plaster mixes (internal use only ) Guidance Table 4: Mix ratio for lime render/plaster coats Application Type of lime Lime: aggregate mix ratio by volume Comments Internal plaster Base/levelling coats As above table 1 : 2.5 or 1 : 3 sand/aggregate Add hair/fibre at 1.5kg per tonne to provide tensile strength (unless using polypropylene render mesh, and that it is towelled into the first coat.) Top/finishing coat As above table 1 : 2.5 or 1 : 3 fine sand Use finer sand External render Base/levelling coats As above table 1 : 2.5 or 1 : 3 sand/aggregate Top/finishing coat As above table 1 : 2.5 or 1 : 3 fine sand Use finer sand Harling/roughcast finish coat As above table 1 : 2.5 or 1 : 3 course sand Apply to external render with Harling trowel or Tyrolene machine Notes: Above are suggested render/plaster mixes only and the actual mix is to be specified by