How To Survey Historic Properties for Damp Advice, House Guide, Home Decor

How To Survey Historic Properties for Damp

22 Nov 2020

Annabelle and Dean Webster Southeast Timber And Damp:

A significant part of our damp proofing work takes place in historic properties. Helping the owners, supporting them with building remodelling, redesign, and repairs is an exciting challenge for the team and one they particularly enjoy.

However, it can be a sensitive area and one that requires all due care and attention. Quite rightly, we understand that homeowners have a strong attachment to their property, but just as importantly, it has a special place in the history of the town or village within which it sits.

Recently, the Property Care Association (PCA), our trade body, worked alongside RICS and other organisations to create a written methodology regarding surveying historical or period properties in regards to damp defects and building repairs.

This document was very welcome as it supported the way we already work, but it also ensures the wider industry are trained and guided on this way of surveying.

Here are the critical areas of the report to help you understand the approach for undertaking building repairs on a historic or listed property.

Stage 1A – Understanding the building context

The first requirement is to take a holistic view. All parts of the building are interlinked and require an assessment that takes account of the full picture.

It is crucial to consider the age and construct of the building, along with the types of materials and techniques used. This stage also requires a review of the immediate surrounding area such as pathways, drives, sunken areas, flood areas, elevation, ground levels, drainage and plants, trees.

This contextual review will take various temperatures from around the building and focus on high-stress areas, such as those exposed to the elements.

The final aspects to include at this stage are any alterations or additions made. In reviewing any changes to the original building, it is essential to make a note of any newer materials used.

Stage 1B – Understanding The Building: Differences between old and new buildings

Traditional buildings are constructed entirely different from new buildings.

A surveyor requires knowledge of the various build and construct types, along with an understanding of the multiple methods and techniques.

The moisture level differences between modern and period properties are vastly different. Similarly, the thermal properties, along with varying occupant levels, can affect the various types of buildings in a very different way.

Stage 2 – Understanding moisture

To survey a historic building requires the surveyor to have a clear understanding of the various forms of damp and its relationships with multiple materials.

We have included a link to the document released, which details the

substantial knowledge required to understand a damp issue in a historic building fully.

Stage 3 – Understanding moisture-related building defects

Different styles of building have different types of building fabric deterioration based on the various construction methods and materials used.

These defects affect different parts of the building and must be reviewed.

There are several aspects to consider when conducting this review, including but not confined to:

The effect of moisture freezing within porous materials and then defrosting
When moisture dries out, and it leaves salts and/or moulds
Corrosion of metals

An infestation of timber affected by moisture
The decay of moist timbers
The types of fungus as some are very similar but affect the building very differently

Ventilation or lack of it is a consideration as well as heating and insulation positions.

Stage 4 – Diagnosis and Recommendations

Once the survey has been carried out, and all of the above matters considered it would be time to provide recommendations for the best way to resolve the building repairs.

This is not always a “one-stop” solution – it may require small steps in first addressing and stopping the source of moisture along with making changes to ventilation, airflow, removing materials then monitoring the matter over some time.

The recommendations for the works are all to be in accordance with Heritage Building Regulations and any listed property restrictions.

Some works may require listed building consent from the local council.

Any works should have as little impact on the building as possible. The above considerations, as well as legal and regulatory legislation, needs to be referred to in regards to any historic building works.

Comments on this guide to How To Survey Historic Properties for Damp article are welcome.