Application Guidelines
Limewash as supplied by Ingilbys is a thick dilutable material and unless specifically instructed otherwise the material should always be diluted with fresh clean water immediately prior to application, this is to enable the limewash to penetrate the substrate or previous coat of limewash. Dilution levels will vary depending upon conditions at the time and which coat is being applied.
Surface Preperation
The most common surfaces to be limewashed are new lime plaster/render, new cementatious based plaster/render,
a mixture of both or previously limewashed surfaces. Newly rendered surfaces must be given sufficient time for the render to have ‘cured’ and dried out , on no account should limewash be applied to ‘green’ surfaces.
Extreme care should also be taken with surfaces that have been ’spot’ repaired. The use of silicone or polymer based fillers, sealers or water proofers are generally impervious to water and very often lead limewash failing to adhere. All loose materials should be removed from the surface to be coated. The substrate must be free from dirt, grease and any other contaminants likely to impair adhesion or absorption. It should be remembered that any repairs carried out (filling of holes, cracks etc.) are very likely to be of a different porosity to that of the rest of the substrate and therefore will offer a different absorption rate to the limewash, this may well lead to patchiness when the limewash is applied.. On bare render the surface should always be ‘damped’ down prior to the limewash being applied as this cuts down the render drawing out the water from the limewash at too quick a rate.
The result if this happens is a limewash that has very little ‘wet’ time, cannot be worked into the surface which ends in too thick a coating being applied which then ‘mud cracks’.
There are some basic rules/guidelines for using limewash.
After the surface has been prepared always ‘damp’ down prior to application. Do not work on too large an area at any one time. Thin the limewash with clean fresh water immediately prior to application. On bare render dilute with 100% water (e.g. 5 litres water to 5 litres limewash) for the first coat. Second and third coats of limewash should be thinned with at least 20% water, this will enable the limewash to be worked into the surface of the previous coat. On warm dry days it is also recommended that each previous coat of limewash should be ‘damped’ down prior to applying subsequent coats. It is important to recognize that each tub of limewash should be thinned with the same amount of water on each elevation of the building as failure to control dilution levels will result in uneven coverage and a patchy finish. Plan the wash in advance, NEVER coat in full sun as this will result in too fast a dry time and leads to a poor finish. Brushing is the recommended method of application, using a roller can result in too thick a coat being applied and this can also lead to a poor finish resulting in the limewash ‘mud cracking’.
Remember it can take several days for the limewash to dry out, only then will the final colour be achieved as varying moisture levels and atmospheric conditions can give variations in the tone of the limewash.