A Parapet is a low wall usually found on the edge of a roof on buildings.  

A Parapet is also the term used to describe low walls around roofs and flat roof terraces.  Parapet is also the correct word for similar low wall barriers used in castles, fortified structures, churches and cathedrals.  

The term comes from the Italian ‘parapetto’ (parare = to cover or defend, and petto = breast).

Types of parapets

  • Plain parapets are simply extensions of the wall, sometimes they have a coping at the top.
  • Embattled parapets have ‘piercings’, turret-like structures that tend to have a purely stylistic purpose. Originally they were used for the discharge of defensive projectiles.
  • Perforated parapets are pierced in various designs such as circles, trefoils, quatrefoils.
  • Panelled parapets are ornamented by a series of enriched, but not perforated square panels.  

History of parapets in London

Parapet roofs are extremely common in London. After the Great Fire gutted the city in 1666, the Government enacted a series of measures that were aimed at making the city fire resistant. The Building Act of 1707 banned projecting wooden eaves across the cities of Westminster and London. It was deemed that the wood created a fire risk.  

While the stone parapets were excellent fire retardants, they were unfortunately weak points in the water proofing of the property.

Leaks occurring at parapets are now a common cause of under-roof rot, condensation and borer infestation.