Period properties

Damp in period or historic properties

admin Damp, Period properties

Damp is a common issue for old houses, whether period, historic or listed. The Multiskill team have worked on a number of historic buildings in the Yorkshire area, as well as many typical period homes, so are well-placed to look at the problem and how to treat it.  

Older properties were built using different methods to those of today and have an increased tendency to condensation and damp. In the UK, we have a large amount of housing from Edwardian and Victorian times, in which damp is a common problem.

It may surprise you to know that the damp proof course is not a modern invention. Some form of damp proof course can be traced back to the Romans. As excellent engineers, they recognised the phenomenon of rising damp and had efficient solutions to combat it. For example, Roman architect and engineer Vitruvius in his famous ‘Ten Books on Architecture’ recommended a special type of plaster mix that should be used on the lower parts of the walls (those subject to ground moisture).

This picture shows another common Roman technique of using a horizontal course of slate inserted in a wall to act as an impervious barrier.

A Roman damp proof course at Hardknott Roman Fort

Moving forward in time, although the builders of Georgian houses (1714 – 1837) understood the need for good ventilation, there was no formal system for damp proofing.

In Victorian times (1837 – 1901), solid walls were common, often leading to condensation. Timber frames were also routinely used; these are vulnerable to rot. 

However, later in the Victorian period, cavity walls were introduced. A cavity wall is made up of two walls with a gap in between, known as the cavity; the outer layer is usually made of brick, the inner of brick or concrete block. The air between the two was meant to stop damp passing from outside to in. 

The use of air bricks also began in this period; they were used in walls and under floors to help increase the amount of air in a building and provide improved ventilation.

Damp proof courses became compulsory in 1875, but many installed in the immediate period after this were poorly laid and no longer fulfil their purpose. Initially, damp proof courses were slate or lead barriers, fitted into the walls to protect against rising damp (much like the Roman example shown earlier!). More modern properties used bitumen felt, but today’s properties most commonly rely on chemical injection or a physical damp membrane.

Georgian, Victorian and Edwardian houses (image from Foxtons)

There are many causes of damp in older properties, and identifying the root issue is the first step in combatting damp and mould. It can be hard to differentiate between rising damp, penetrating damp and condensation, so getting an experienced company like Multiskill to diagnose the problem is sensible and can save money in the long run.  

Sometimes damp problems in older houses have been caused by ‘improvements’ such as:

  • Adding pebbledash to the exterior walls
  • Using inappropriate waterproofing treatments which prevent the building from ‘breathing’
  • Blocking of airbricks or vents
  • Adding flowerbeds or driveways above the natural ground level, meaning the damp proof course is no longer in the correct place and water is absorbed above it

Not treating damp can lead to a host of problems in older properties, including:

  • Unpleasant musty smells
  • Health problems like asthma
  • Structural damage to the building
  • Damage to furniture and soft furnishings
  • Heat loss and bigger energy bills

If you’re considering buying a period property, we always recommend a specialist damp and timber survey. This will identify any existing damp problems and as well as other property care issues like timber rot or woodworm infestation. It’s important that you choose a professional, PCA approved damp proofing contractor like Multiskill, who can correctly diagnose the issues and recommend the most effective treatments.

If you’re concerned about damp in a period property you already own, don’t hesitate to contact Multiskill for practical advice.