External Redecoration - Choice of Paint
Some 20 years ago it became clear that the major cause of breakdown of paint decoration on stucco surfaces of mid-19 th century buildings is inherent seasonal movement of the structure, leading to fine cracking of the stucco rendering and the build up of coatings applied thereto over the years. The traditional lead, and later alkyd, paints used in these situations become very hard and brittle and have a tendency to delaminate and crack and craze with the movements in the structure. Water ingress at these points subsequently causes lifting and curling back of the edges of the paint film.
After appropriate research, TOLA adopted the acrylic paints produced by Dacrylate Paints Limited. These paints remain slightly plastic over the years and, if painted directly onto a stucco or previously Dacrylate painted surface, will resist very fine cracking and will not curl back at the edges.
A further advantage of Dacrylate is that due to its characteristic to bond one coat to another Dacrylate coat, separation of coatings does not occur. Further, on surfaces maintained in good repair, one ‘refresher' coat of Dacrylate may be sufficient in subsequent painting cycles.
The Dacrylate paint system has good colour retention, enabling the painting of larger terraces to be phased if desirable as separate contracts during a painting season or over subsequent years.
Dacrylate acrylic paint also has microporous properties which will allow moisture vapour, although not droplets, to evaporate through the paint film.
Thorough pre-painting preparation is paramount to the success of any paint system and, in order to achieve the full advantage of using acrylic paint on stucco surfaces, it is beneficial that any old brittle paint films be removed back to the bare rendered surface; this also has the additional benefit, after many years of paint build up, of revealing the clarity of the original architectural moulding detailing to cornices and architraves.
The use of Dacrylate acrylic paint on stucco surfaces on the South Kensington Estates has been a significant success over the past 20 years and remains our preferred choice and recommendation for principal terraces. In the case of the Anstruther South Kensington Estates, this particularly relates to the three sides of Thurloe Square and will also continue to be our advice.
However, in recent years, the masonry coatings divisions of other leading paint manufacturers have also developed decorative paints suitable for use on stucco surfaces of listed and conservation area buildings. Such manufacturers include Johnstones Paints and ICI Dulux. In the case of the smaller scale and more individual properties of say South Terrace and Alexander Place, such products would be acceptable, subject to colours being true white (BS 00 E 55) not “brilliant” white and to the level of surface texture and reflectance being consistent with conservation area policy, all in order to maintain the overall appearance of the Estate.
Some questions often arise as to the identification of previous use of Dacrylate paint on stucco. In these cases our records may be of assistance or arrangements can be made for the Dacrylate London Area representative to call on individual owners and, by a simple process, identify Dacrylate material.
Timber and Metal Surfaces
Timber and metal surfaces require less technical discussion; although thorough pre-painting preparation remains paramount. Johnstones and ICI Dulux paint products are recommended on both these surfaces.
True white (BS 00 E 55) not ‘brilliant' white should be used for windows and door frames and black paint for railings and rainwater gutters and downpipes, save where the latter pass painted stucco surfaces when they should be painted white to match the background. Front doors in Alexander and Thurloe Squares should be black, whilst those in the smaller streets may be painted in suitable colours from the historic colour ranges developed by ICI Dulux or The National Trust.
Dacrylate Paints Ltd
London area technical representative –
Mr P Copson
Telephone: 01623 753 845
Mobile : 07778 863 987
Johnstones Paints Ltd
Unit 401/405 Old Field Lane North
Telephone: 020 8575 1604
London technical representative –
Mr A Walker
Telephone: 01924 354107
Mobile: 07718 514025
Telephone: 0870 241 0889
London area technical representative-
Mr C Argent
Mobile: 07720 068 355
Issue 2: 23 rd June 2005 S A Crowsley