Resources

Bricklayer / Plasterworkers

Bricklayers

Brickwork (mortars and pointing) Raking out and repointing of brickwork, if carried out incorrectly, can lead to permanent and extensive damage to brickwork. Procedures for repointing should be carefully laid down; the use of mechanical saws and grinders should be avoided, if possible, on historic facades. Correct pointing will enhance the appearance of the façade.

If damaged bricks have to be replaced, care should be taken to match existing colour and texture, possibly using salvaged bricks. Damaged bricks can sometimes be reversed. Dense cementicious repairs only cause further damage.

Mortars, like renders, must be pliable and porous and the most important ingredient in this respect is lime. Lime based mortars allow moisture which is absorbed into a building to evaporate safely. Cement based mortars are hard and impermeable, and water and moisture, trapped inside, have no means of escape, except through the bricks, causing damage.

Cleaning brickwork The repair and cleaning of brickwork and stonework demands skilled operatives, following a careful specification, and using appropriate methods. Cleaning is not always necessary. Inappropriate abrasive cleaning methods can cause irreversible damage. Cleaning procedures require careful specification and the skills and experience of trained operatives. If in doubt, don't clean.

Structural defects, resulting from decayed timber elements, or foundation movement, should be rectified prior to any repair or cleaning. This sort of remedial work, as well as the repair of wall cracks arising from timber failure or settlement, is part of the experienced conservation professional's expertise.

Plasterworkers

External Plasterwork Traditional buildings require flexibility of movement, so that moisture can be absorbed into the building and evaporate out again. Renders (and mortars) must be pliable and porous and the most important ingredient in this respect is lime.

Lime based renders were in universal use up to the early 19th century, until the use of cement based products took over. Cement based renders and mortars are hard and impermeable, and water and moisture get trapped inside with no means of escape. This leads to damp timbers or damage to bricks and stone as the moisture is forced out through them.

Houses built of rubble stone, and then rendered, are traditional and can be found all over Ireland, giving character to our towns and villages. The current trend to remove the protective and charming render, leaving the stone exposed, is inadvisable technically and visually. In general, rubble built walls were never meant to be seen and, as well, the house loses its protective and insulating skin. These exposed walls are often pointed, in cement with a raised crazy paving effect, which again is visually wrong as well as potentially damaging, and particularly inappropriate in a terrace of traditional rendered houses.
Internal Plasterwork Traditional internal plasters were made with a lime and

sand mixture. This produced a crack resistant soft plaster, which took a long time to harden. In more recent times, it has become customary to add cement, to speed up setting times and increase hardness. In general, this should be avoided, if possible. If cement has to be added, because of the substrate material, or for other reasons, as little as possible should be used and it should be avoided in the final coat.

Resources

Bricklayer / Plasterworkers

Bricklayers

Plasterworkers

Further Reading