When Stone Sheds its Skin
"Exfoliation" or spalling is when the top 2-3mm of the stone flakes off. It looks terrible and ruins the patio.
The Cause: Salt & Ice
Sandstone like Mint Fossil is porous. Water enters.
Winter: The water freezes and expands, popping the surface off.
Salt: If you use de-icing salt in winter, the salt crystallizes inside the pores, creating massive internal pressure that shatters the stone face.
The Cure
1. Never salt sandstone. Use sand for grip instead.
2. Seal it. A breathable impregnating sealer keeps water out, minimizing the freeze-thaw risk.
3. Drainage: Ensure the patio has a 'fall' (slope) so water doesn't pool and sit on the stone.
#Sandstone#Damage#Winter#Maintenance
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