It has been suggested that if one thing could be banished from old buildings it should be the use of cement. Agreed. And we would add that the second material to be abolished should be modern paints.
The appeal of being able to quickly improve the appearance of a building using modern plastic (alkyd) paints is undeniably attractive. However, the impermeability of these paints prevents a building from performing as it was intended by trapping moisture within the wall, accelerating its decay. The decorated wall may look good for many years but the paint is often causing damage to the substrate behind. It can cause brick, stone and plaster to spall due to frost damage or through increased concentration of salts and can result in timbers rotting due to increased dampness.
It is therefore often beneficial to remove modern paints. Unfortunately, removal is easier said than done. Sometimes paint will lose key and can be lifted off with a palette knife, but usually large areas remain tightly bonded to the wall. Various paint removal systems are available to the conservator, including paint-on chemicals and 'packs'. In addition, softening the paint using steam, super-heated up to 150ºC, is often the most effective and least-invasive. Proprietary conservation systems are available that minimise the quantity of water entering the substrate and avoid abrasive scrubbing of the wall surface.
Once the paint has been removed and any other remedial work completed (such as repointing and plaster repairs), the wall can be redecorated with a more suitable finish such as limewash or, for stone, a sheltercoat may be beneficial.
During inspection of local buildings, Tony Graham & Co has often noted modern paints that are best removed. To ensure we can offer the most appropriate method of removal, we have invested in the DOFF steam system. Tony Graham personally carries out this work to ensure the greatest care is always taken when operating on historic buildings.
If you believe there may be a need to remove paint from your building then please contact us for further advice.
Removal of Paint from Daub Infill.
Wright, A. 'Removing Paint from Old Buildings', SPAB, London, (1986. 3rd. Ed 1994).
©Copyright 2005, Tony Graham & Co.