Ridout Associates offer a range of different surveys, analysis services, expert advice and monitoring programmes. Homeowners, architects, structural engineers, chartered surveyors and heritage organisations (including English Heritage and the National Trust) frequently contract us for a variety of investigative works.

Our surveys can provide the following specific information:

Timber Decay

Ridout Associates are independent consultant biologists with a wide experience in providing advice on dealing with dry rot, wet rots, deathwatch beetles and other building pathology issues.

Our recommendations are based on an assessment of an insect or fungus’s current level of activity, and of its potential to cause further damage when building works have been completed. Our reports provide recommendations and specifications designed to deal with the causes of decay within buildings and we do not sell chemical treatments that only attempt to control the symptoms. Decay organisms that continue to pose a risk are identified and site-specific recommendations for their control or eradication are provided.

By employing an objective scientific approach to infestations and decay problems we are able to provide long-term recommendations based on environmental modification. Our approach minimises remedial treatments and provides clients with a cost effective method of solving current problems and reducing the risk of future decay.

The first aspect considered is whether there is a current problem: a high percentage of the fungus and insect attack that is treated in buildings is historic and dead, or has very little ability to cause significant damage. Remedial companies sell treatments, so that a minimal approach to intervention has little appeal for them. Millions of pounds are spent on needless dry rot repairs each year alone. Analysing the extent and severity of damage can also avoid a significant amount of needless and ineffective ‘woodworm’ treatments. We do not specify unnecessary blanket treatments for these beetles, instead highlighting the areas of activity to enable targeted use of insecticide.

Recent timber decay survey projects

 

Non-destructive Timber Testing and Strength Grading

To augment our timber decay surveys we can employ a range of non-destructive testing techniques including a micro-drill for detecting concealed decay. This instrument is particularly useful in establishing the condition of embedded timbers without the need for intrusive removal of masonry or costly replacement or support of bearings. We frequently use these drills when investigating oak timber framed buildings suffering attack by deathwatch beetles as the damage caused by these insects is often worst at embedded bearings.

Micro-drill analysis can provide information useful for structural assessment of buildings, particularly in re-use projects where changes in internal loading are necessary. Whilst we cannot make structural judgements we can provide cross sectional analysis of timbers to assist shear strength calculations together with recommendations for the repair of damaged sections and options for support.

In order to reduce the need for potentially damaging exposure work we use endoscopes to inspect voids and cavities within buildings where we feel it to be appropriate.

We can also visually strength grade historic timbers in situ to BS 4978: 1996. This type of survey is useful in determining the levels of support required (if any) for load-bearing timbers.

Recent micro-drill surveys
Recent strength grading surveys

Damp Masonry Analysis

We offer a damp analysis service. An accurate assessment of damp can only be made by a laboratory investigation of masonry samples removed from the walls. Our reports include recommendations based on these investigations.

It is our experience that high ground levels, faulty rainwater goods and blocked or damaged drainage systems are frequent causes of damp in walls. A superficial assessment of the internal surface with a moisture meter will not differentiate between sources of damp. It is important to remember these meters do not measure moisture: they measure electronic conductivity, which is influenced by a number of factors in masonry, not just water.

By ascertaining the source of the water and the severity of the problem, recommendations can be made to resolve damp issues without resorting to destructive and irreversible damp-proofing treatments. Most instances of damp can be ‘designed out’ with basic building work.

Recent damp surveys

 

Environmental Monitoring

Monitoring environments and specific parts of a building’s fabric can provide useful information as to the distribution of water and its interaction with the building. This information can be factored into drying regimes and other aspects of repair or renovation works.

We offer a range of monitoring options to analyse internal environments and changes within masonry and wood.

Recent environmental monitoring surveys

 

Fire/Flood Damage Monitoring

We are particularly experienced in providing independent consultant advice on water movement and the risks of timber decay following fire damage and flooding of buildings. We routinely undertake monitoring programmes to determine the drying rates and profiles of buildings, which help to inform refurbishment schedules.

Recent surveys/monitoring work relating to fire or flood damage

 

Expert Witness

We prepare reports for loss adjustments and building guarantee disputes. The legal works undertaken are often for cases relating to timber decay and damp in buildings, particularly those involving dry rot (Serpula lacrymans).

Recent expert witness cases

 

Termite Control Advice

We have undertaken consultancy work on termite control in Turkey, Morocco, Bahrain, India, Greece and Vietnam on behalf of UNSECO and The Getty Foundation as well as for private clients. We employ the same environmental control approach to termite advice as to domestic timber pests. We have achieved good results with minimal use of pesticides.

Recent termite infestation surveys

 

Lectures

Ridout Associates routinely provide lectures and seminars to academic and professional organisations on subjects relating to damp and timber decay in buildings and the benefits of a holistic approach to their treatment.

Recent lectures

Beetle screen light traps

Due to escalating costs, we have decided to cease production of Beetle Screen Light Traps. However, we are still able to supply replacement sticky pads and bulbs for customers who have existing traps.

Timber Decay in Buildings book

by Dr B V Ridout
ISBN 0-419-18820-7
Awarded the Best Technical Publication of 1997/2000
by The International Association of Preservation Technology

Timber Decay in Buildings is the first book to tackle all the issues relating to timber decay. It presents the facts and explores timber decay problems through case studies. These are illustrated with clear self-explanatory photographs for the reader to use as a diagnostic aid. The methods outlined are intended to reduce unnecessary damage frequently caused to buildings by uninformed timber treatments, and form the basis of the timber conservation methods advocated by English Heritage and Historic Scotland.