Wattle & Daub: Craft, Conservation & Wiltshire Case Study
3.6 Daub
4.1 Soils
4.1.3 Strength
4.2 Dung
4.2.2 Lignin
4.2.3 Urine
4.3 Fibre
5.4.2 Renewal

Title Page Previous Next | Conservation >Repair >Removal of Impermeable Paints and Coatings

5.3.2 Removal of Impermeable Paints and Coatings

It is often found that wattle and daub panels have been covered with impervious coatings such as exterior emulsions, masonry paints and high-build ‘construction paints’. This may cause rapid decay of wattle and daub and it is therefore desirable to remove them and replace with limewash.
Modern paints will often delaminate after approximately five to ten years after application. They may then be removed by carefully lifting off with a small trowel or scraper.
Where modern paint remain firmly bonded to the plaster or daub, the choices are either to leave the paint and attempt to monitor the condition of the wattle and daub or to use a more aggressive method of removal. Latterly, there has been much research into the removal of paint for the conservation of stone and brick. The industry has developed its experience in the use of chemicals, dry abrasives and poultice strippers. Unfortunately, there is very little experience in paint removal from earth materials such as wattle and daub and cob.[96]
Paint Removal Case Study

A timber frame building in Wiltshire had been ‘modernised’ during the 1980’s. The panels were of hazel wattle, daub and a lime plaster top coat. Some panels had been painted using an exterior emulsion, some with a high-build ‘construction’ paint and some coated with proprietary textured wall coating. The following conservation work was performed during 1999 and 2000:
  • The emulsion had become flaky. Small sections were easily peeled away with a scraper, but many areas remained bonded. The thinness of the paint made it difficult to position a blade underneath without damaging the panel. The construction paint appeared intact but had delaminated in large areas. Once a pallet knife was under the paint, large areas were easily removed. Some areas remained tightly bonded to the plaster. The wall coating was thick and remained well bonded to the plaster.
  • Chemical stripping of the two paint types was attempted. Firstly, the timbers were protected to avoid bleaching and staining. The formula selected was a combination of solvent and caustic strippers comprising methylene chloride and ammonia, which was applied by brush. A scraper was used for the cleaning, followed by hand rinsing with water using a sponge. A water lance was not used. The dwell time was adapted so that the resulting ‘jelly’ could easily be scraped away, but not left so long that it began to dry. The method was particularly successful on both paints. No residue was noted and the panels readily accepted a limewash. The stripper had no effect on the wall-coating.
  • A caustic poultice stripper based on sodium hydroxide was tested. Removal of both paints was successful. However, the residue was harder to rinse away than the chemical product and it left an odour in the panel that indicated a residue had been left in the plaster. These panels also accepted a limewash after priming with limewater. There was no effect on the wall-coating.
  • Dry-abrasive was thought to be a possible candidate for sensitive removal of the paints. Careful control by skilled operators can often remove coatings without damaging the substrate. It was felt that limited damage to the plaster could be tolerated since it could be easily repaired. This method was not tested and so its capabilities on wattle and daub remain unproven.
  • The wall-coating had been used only on the upper storey of the leeward side of the building and where the panels were sheltered under the eaves of thatch. It was decided to take a pragmatic approach by leaving the wall-coating on. The panels would be monitored for dampness. It was decided that if, in the future, decay was noted, the coating could be removed along with the plaster and refinished.

[96] There is no published reference to active paint removal from wattle and daub. Enquiries to well-established operators dealing with chemical and dry-abrasive solutions indicated they had no experience of wattle and daub.