Back to basics - Whitewashing

When confronted with an abundance of products when it come to masonry paints it can be quite confusing, especially when you are working in an older property without damp proofing and you would like to allow the masonry to 'breathe'.
It was for this reason that we decided to go with traditional whitewashing.  Whitewash (lime and water) can be easily prepared at home.  Lime wash besides being breathable has certain advantages namely:

• very cheap to prepare
• has fungicidal activities 
• seems to deter wood bring beetles
• does not contain petrochemicals and is therefore greener

Disadvantages include:

• difficulty in matching different batches so mix all you need in one go
• can rub off on clothing
• may need a new coat every few years

Preparing the whitewash
Needs list:
Clean bucket, lime, drill with mixing paddle, water, gloves, eye protection, respirator.

Lime (gir) can be easily bought from most ironmongers.  It must be mixed carefully as it is caustic (will burn), so gloves, eye protection and a respirator are essential.

• mix the lime to the water not vice versa, this will reduce airborne lime dust (even though you should be using a respirator).  Use the drill and mixing paddle for this.  Keep the revolutions low so as not to raise a cloud of lime dust.  Mix until the mixture has the consistency of milk
• Close the bucket and leave it for a few hours.

Applying lime wash

Lime wash cannot be applied to any surface.  In our case it was limestone which is a suitable substrate.

Needs list:

Safety gear as above, paintbrush, spray gun, brush, stirrer

Ceiling prior to painting

• the surface to be painted (in our case a limestone slab ceiling) should be brushed to remove any loose particles and dust
• the area should be sprayed with water (lime wash should always be applied to a moist surface).  Spray the surface as you go along as (dependent of weather conditions) it may dry out fast.  I used a spray gun with an adjustable nozzle set to a fine mist.
• all that is left is to apply the wash with a brush.  Do not apply thickly.  At first it will seem as if you have barely covered the surface but with a few hours the colour will come through.  The paint was stirred at intervals during the process.  A second coat can be applied. I applied this after 24 hours, however the surface was moistened again in the same manner.

After 2 coats