Client: Domestic
Our client, a homeowner in Southampton, tasked Timberwise with surveying the property for problems associated with dry rot fungal decay. This property was a detached house of cavity brick construction, and was both occupied and furnished at the time of our inspection. The property had been built circa 1930, and the structural walls were cavity brick with an external render. Our inspection was limited to the property’s living room and utility room. The weather conditions were overcast but dry.
Challenges
The inspection was restricted strictly to locations the client specifically requested, which included the front right ground floor room and the utility room. There was a significant challenge during the assessment, as there was limited visibility and physical access to the area due to the fitted floor coverings and fitted units.
We noted that there was a restriction to the subfloor’s airflow which was being caused by blocked air bricks, which was most likely due to the cavity wall insulation failing or faulty. There was a strong risk of rapid fungal spread and severe structural damage if the dry rot issue was not taken under control quickly.
There was also an obligation on behalf of the client to remove all floor coverings, furniture, stored items, skirtings, and lounge units prior to our technician’s arrival on site.
Observations
No external inspection of the property was completed, as the inspection was requested solely for the living and utility room. Our surveyor found an active dry rot fungal decay outbreak in the property, which was identified within the internal ground floor timbers which was affecting the aforementioned rooms. Inadequate subfloor ventilation was noted beneath the floor space, owing to the air bricks being obstructed because of the cavity wall insulation.
Solutions
To prepare the area for treatment, we protected unaffected areas by taping down dust sheets and hardboard to floor surfaces to limit dust settling. We covered any large, freestanding personal items in the work area with polythene sheeting. We removed all of the affected, existing wall plaster up to one metre high, bagging debris and disposing of it off-site to prevent the dry rot from affecting anything else.
To control the dry rot outbreak, we created a toxic box barrier (cordon sanitaire) across the affected masonry walls. We drilled holes ranging from 12mm to 16mm in diameter at 450mm staggered centres in a 300mm wide band around wall perimeters exceeding 150mm thickness and around wall openings. We then filled these holes with a LignaTek Fungicidal Treatment alongside a surface application to all affected wall perimeters, effectively containing the outbreak.
For the timber replacement, we cut back four linear metres of the affected wall plate to sound timber and replaced it with pre-treated timber. We coated cut ends of wall plates with a fungicidal treatment and isolated it from the masonry using a damp proof course membrane. We repeated this process to remove and replace all of the affected floor joists as well. We then removed degraded floorboards and replaced them with a 22mm treated moisture-resistant chipboard flooring.
To resolve the precipitating issue of the poor ventilation system, we supplied and installed new plastic air bricks complete with sleeves to restore subfloor cross-ventilation and prevent airflow blockage from the cavity wall insulation.
To finish off the project, we re-plastered all the treated wall areas up to one metre in height, using our standard specification which included incorporating specialist salt-inhibiting additives such as a DryTek DPC and finishing system.
Results
Our team successfully identified a dry rot outbreak across the ground floor lounge and utility spaces, also providing the client with a detailed map of defects caused by the dry rot throughout the area.
We were able to completely eradicate the dry rot infection and contain any potential future fungal growth through the use of a chemical toxic box masonry treatment. We structurally reinstated the floor joists, wall plates, and decking that had been affected using pre-treated timber that we isolated from wall surfaces.
We were able to permanently restore the subfloor ventilation to prevent moisture accumulating and causing any further dry rot or other damp-related problems. We reinstated wall surfaces using a salt-inhibiting plaster to allow for natural wall drying whilst protecting the client’s decorative finishes. All of this work was backed with a 10-year guarantee which covered the dry rot treatment, timber replacement, air bricks, and DryTek plastering.
Do You Want Help with a Dry Rot Solution?
Our dedicated and experienced team in Southampton are ready to talk to you about your options for property preservation. Don’t hesitate to call us on 01489 807063, or you can request a survey online.
