COATINGS & FINISHES
SHOULD I REPAIR OR REPLACE LIME PLASTER? Lime plaster is extremely hard-wearing. It can last for hundreds of years, flexing as buildings move, regulating moisture and ensuring the building remains dry over time. Many older houses or historical buildings include lime plaster that is centuries old. LIME GREEN PRODUCTS
L
ime’s qualities, such as flexibility, breathability, durability and damp resistance, allow it to be repaired in a wide range of situations. But, when your lime plaster begins to appear aged and damaged, should you repair it or replace it? Simon Ayres, Co-Founder and Managing Director at Lime Green Products, shares the key indicators that can help you to decide whether repairing or replacing is the best option for you, sharing the techniques for doing so successfully. Replacing plaster can be expensive, so it’s important to ensure you make the right decision. Identifying problems and determining which method is suitable requires skill and knowledge. However, there are methods of salvaging and reattaching old ceilings and walls, so damage doesn’t necessarily mean replacement.
For most renovation projects, there are four options to breathe new life into older lime plaster: patch repair, reskim, replace or repair the key from above.
What are the options?
2. Reskimming
It’s difficult to replace older plasters to the same standard they once were, so, wherever possible, salvaging and repairing the existing material is key. Repairing can also provide a more authentic result, which can last for another lifetime or two. When refurbishing any existing plaster, it’s important to evaluate the materials and choose a complementary plaster for repair work. This is important to ensure the materials bond properly and stand the test of time.
It’s not uncommon to need a fresh top layer of plaster. In this process, it’s important to use a primer to ensure the new materials bond well with the old. Be sure to select a primer that matches the plaster. For example, when using lime plaster, consider using a primer that isn’t acrylic to retain breathability.
FC&A – MARCH – 2021
1. Patch repairs For small, aesthetic cracks caused by movement, patch repairs can be particularly effective. It’s important to evaluate whether a smooth and consistent finish can be attained, without the necessity to reskim the entire wall or ceiling. Specific plaster repair systems are available for small patchwork repairs, created to consolidate lime-lath plaster and historical limework.
26
3. Replacement For replacement, it’s still important to review the original structure of the wall to determine if any existing materials can be salvaged and rejuvenated in the remedial work.
4. Repairing the key Ceilings made from lath and plaster or highly ornate fibrous plaster can still be aesthetically pleasing, but they may be slowly detaching from the wooden or hessian supports holding them in place. The material can then eventually come loose and fall to the ground. This has been a common problem in theatres. There are now rules in place to survey and repair plasterwork ceilings in public buildings. The material can be repaired from above, by stabilising the hidden support structure and re-bonding the plasterwork.
Possible damage and how to repair Before undertaking any renovation or refurbishment work, you will need to address the issue that caused the damage in the first place, to prevent the possibility of the same issue reoccurring. Types of damage may include:
