Sash Window Sand Mastic Repairs

Eco sash & case use burnt sand and linseed oil mastic as this is the original method for pointing the outside facing of the sash window to the stonework. This method of sealing is the preferred option for listed buildings and conservation areas in Scotland for its original look

The old and loose mastic around the window where the cement meets the stonework is removed as is the backing that is behind it. This is replaced with trade quality expanding foam which helps to improve the insulation.

The expanding foam also provides a solid base for the new sand mastic to be fitted against it to form a long lasting, completely wind and water tight flexible joint between the outside masonry and the timber frame. We then coat the new material with PVA. Finally, we hand apply the traditional sand mastic.

This is the original method for sealing the outside facing of the sash window. It is hand applied using a pointing trowel. This method of sealing is for it’s original look.

  • Cut out old window backing & mastic
  • Apply expanding insulating foam
  • Apply 1 coat PVA bonding, if required
  • Re-mastic windows by hand using high quality sand mastic
  • The mastic is available in red & natural to match the sandstone building.
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