Care & maintenance of outdoor sculpture

Portland stone sculpture

Portland stone is suitable for permanent outdoor display.

My Portland stone sculptures are treated with a stone sealer to help protect against staining and frost damage. 
For outdoor pieces, over time a natural patina will develop on the Portland Stone and the outer crust of the stone will harden. Many people like this natural weathering, others prefer the pristine look.
To help maintain the sculpture's original appearance it can be cleaned with a damp cloth or soft brush and water.

Never jet wash a natural stone sculpture this can force water into the stone causing fissures and deterioration of the natural compaction and cementation of the sedimentary stone. (Jet washing is ideal for concrete and cement)

Any difficult to remove stains can often be lifted with a toothbrush and a natural stone cleaner or a little Milton sterilizing fluid, patch test first and rinse very thoroughly with plenty of water afterwards. But it is best to not clean the sculpture too often (once a year at most) and as little as possible with cleaning products, as it may begin to spoil the surface. A light sanding with fine sandpaper can be effective for stubborn stains if done very carefully, just remember you are removing the surface! Don’t attempt this on highly polished items, detailed or textured surfaces. Using a cleaning product or sandpaper will require the sculpture to be re-sealed once dry.

I find it is better to not place your sculpture too close to any large trees or under overhanging branches as it will begin to green quickly.

If we have a particularly harsh winter it may be best to wrap the sculpture with a blanket/old duvet and plastic or bubble wrap overnight to ensure there is no frost damage.

The stone sealer should be reapplied every 3-4 years after thorough cleaning to help maintain a pristine appearance. I generally use a water-based stone sealer, such as LTP Mattstone H20. Always follow instructions.