Dry Rot Control in a Commercial Premises in Lancashire

Peter Cox were called in to a property in Ashton-in-Makerfield, on the outskirts of Wigan, where a severe outbreak of dry rot had taken hold across multiple floors of the property in the highstreet.

With the building remaining fully operational during the remedial works, Peter Cox were able to carry out a specialist remediation programme to address the extensive fungal decay while keeping disruption to a minimum so business could carry on as usual.

The client had requested a detailed damp and timber survey following concerns about timber decay in the property. They had noticed the tell tale signs of fungal decay, but were unsure on what to do next.

On attending the site, our surveyor quickly identified the hallmarks of a serious dry rot outbreak (Serpula lacrymans), with evidence of sporophores and spore dust throughout both the first and second floors. The ground floor, being used as a commercial premises, was unaffected.

The root cause was traced to ongoing water ingress over several years, linked to unresolved external defects including damaged and defective roof coverings and guttering as well as delaminated sandstone sills and lintels.

A number of additional site-specific challenges complicated the survey process, and recommendations for work:

• Restricted access due to unsafe areas, due to the dry rot outbreak
• Operational restrictions due to the building being an active commercial property, requiring minimal disruption to staff and customers
• Potential asbestos present in wall coatings and flooring, requiring testing and a full asbestos register before works could begin
• Dust and disruption risks linked to hacking off plaster and removing decayed timbers within a public-facing space

To ensure safety, a full asbestos survey was completed prior to works commencing. This confirmed no asbestos in the areas we worked on, allowing Peter Cox to proceed.

In line with Peter Cox best practice, the first step was an exposure survey to uncover the full extent of the dry rot infestation before any remediation could begin.

Once the survey was completed, a full scope of work was provided to the client, along with a detailed method statement. Our repair specifications fully comply with any relevant British Standards.

The recommendations involved:

• Removing wall and ceiling plaster to full height in affected areas
• Stripping out skirting boards and other timber fixtures, which were affected by fungal decay
• Setting up a dedicated waste removal system using skips and a scaffold-mounted chute for efficient disposal
• Providing clear site preparation guidelines to the client, including removing electrical items, radiators, and shelving
• Technicians used a specialist dust filtration unit on-site to minimise airborne dust during disruptive works.

Following the exposure phase, our team developed a detailed specification for the treatment and restoration phase. This included:

• Wire brushing the wall surface to remove any mycelium strands
• Masonry biocide treatments targeting dry rot within the walls and on the surface of affected masonry
• Removal of decayed timbers cut back to at least 450mm beyond all signs of infestation
• Installation of new structural and secondary pretreated timbers
• Fungicidal treatment applied to any retained timbers
• Replastering specifications to restore the interior

Our works were coordinated alongside the main contractor’s responsibility to rectify the external maintenance defects, an essential step in ensuring the long-term success of the internal dry rot treatment.

The exposure works successfully revealed the full scale of the hidden infestation, allowing a targeted plan to be implemented by a trained and qualified CTSDB surveyor.

Despite the logistical constraints of working in a commercial premises still in use, Peter Cox delivered a well-coordinated, low-disruption solution that laid the foundation for long-term structural preservation for the client.

This project demonstrates the importance of early diagnosis and specialist intervention when tackling severe dry rot in commercial properties.

Peter Cox are well equipped to deal with commercial projects, our local teams have the necessary contract management skills in place, and an independently accredited health and safety regime that includes rigorous training for our surveyors and technicians, who carry CSCS cards.