BCD 2017

T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 1 7 139 PROTECTION & REMEDIAL TREATMENT 4.1 References and Further Information V Brito and T Diaz Gonçalves, ‘Artisanal lime coatings and their influence on moisture transport during drying’, 3rd Historic Mortars Conference , Glasgow, 2013 N Copsey, Hot-mixed mortars method etc www.quicklimemortars.com E Hansen et al, ‘Effects of ageing on lime putty’, Proceedings of the International RilemWorkshop on Historic Mortars , Rilem Publications, France, 2000 M Hassibi, ‘An overview of lime slaking and factors that affect the process’, Chemco Systems LP, 2015, http://bc-url.com/hassibi S Jackson, Study on the Durability of Traditional and Modified Limewash Recipes , National Park Service, US Dept of the Interior, 2005 P Nicholson, The New Practical Builder and Workman’sCompanion ,ThomasKelly,London,1823 WMillar, Plastering, Plain&Decorative, 1st edition 1897, reprinted Donhead, Shaftesbury, 1998 CW Pasley, Practical Architecture , 1826, reprinted Donhead, Shaftesbury, 2001 AC Smeaton, The Builder’s Pocket Manual , M Taylor, London, 1840 JA Van der Kloes, A Manual for Masons, Bricklayers, Concrete Workers and Plasterers , revised and adapted by Alfred B Searle, Churchill, London, 1914 David Wiggins, ‘Lime mortar and sacrificial weathering – how it works’, presentation to Hot-Mixed Mortars Forum, Coventry Cathedral, October 2016 C Williams-Ellis, Building in Cob, Pisé and Stabilized Earth , 1919, reprinted Donhead, Shaftesbury, 1999 WHWright, A Brief Practical Treatise on Mortars , Thurston, Torry & Co, Boston, 1845 NIGEL COPSEY of The Earth, Stone and Lime Company (www.nigelcopsey.com) is a stonemason and building conservator based in Yorkshire, and a research associate at the Department of Archaeology, University of York. He is currently contributing to research on hot lime mortars. Hot limewash with salt on the timber walls of the French Jesuit Mission Church (1910) at Fort McMurray, Alberta (Photo: Ben Gourley, MacDonald and Lawrence Timber Framers) A CHEAP WASH For the outside of wooden cottages, barns, out-buildings, fences, etc, where economy must be consulted, the following wash is recommended: take a clean barrel that will hold water. Put into it half a bushel of quicklime, and slake it by pouring over it boiling water sufficient to cover it four or five inches deep, and stirring it until slaked. When quite slaked dissolve it in water, and add 2lbs of sulphate of zinc and one of common salt, which may be had at any of the druggists, and which in a few days will cause the whitewash to harden on the woodwork. Add sufficient water to bring it to the consistency of thick whitewash. To make the above wash of a pleasant cream color, add 3lbs of yellow ochre. For fawn color, add 4lbs of umber, 1lb of Indian red, and 1lb of lampblack; for gray or stone color, add 4lbs of raw umber and 2lbs of lampblack. The color may be put on with a common whitewash brush, and will be found much more durable than common whitewash. Jacques (1860) A TALLOWWASH The basis of most lime wash recipes is the mixing of a quantity of tallow, which may be from 2 to 10lbs, into a bushel of quicklime to form an insoluble calcium soap. The tallow should be placed in the centre of the quicklime and the whole should be slaked together. If the quicklime is slow in slaking [suggesting moderately hydraulic], it should be covered with sacking, and hot water should be used. The addition of pigment may necessitate an increase in tallow, but a useful mean to remember is 5lbs tallow to a bushel of quicklime. C Williams-Ellis (1919) WG SCOTT RECIPES The following recipes are taken from WG Scott’s ‘White paints and painting materials’ ( Modern Painter , Chicago, 1910) and are reliable: ‘Factory’ whitewash for walls, ceilings, posts, etc (interiors) 1 62lb (1 bushel) quicklime, slake with 15 gallons water. Keep barrel covered ’til steam ceases to arise. Stir occasionally to prevent scorching. 2 2½lb rye-flour, beat up in ½ gallon of cold water, then add two gallons boiling water. 3 2½lb common rock-salt, dissolve in 2½ gallons hot water. Mix 2 and 3 then pour into 1 , and stir until all is well mixed. This is the whitewash used in the large implement factories and recommended by the insurance companies. The above formula gives a product of perfect brush consistency. Weatherproof whitewash for buildings, fences, etc (exteriors) 1 62lb (1 bushel) quicklime, slake with 12 gallons hot water. 2 2lb common table salt, 1lb sulphate of zinc, dissolved in a gallon of boiling water. 3 2 gallons skimmed milk. Pour 2 into 1 , then add the milk 3 and mix thoroughly. Lighthouse whitewash 1 62lb (1 bushel) quicklime, slake with 12 gallons of hot water. 2 12 gallons rock-salt, dissolve in 6 gallons of boiling water. 3 6lb Portland cement. Pour 2 into 1 and then add 3 . Note – Alum added to a lime whitewash prevents it rubbing off. An ounce to the gallon is sufficient. Historic sources reveal a wide variety of hot-mixed limewash recipes.