Client: Property Developer
Our client, a property developer in Wakefield, tasked Timberwise with conducting dry rot treatment in their property following a recurrence of fungal decay within the basement. This property was a large, detached house of solid brick construction, and was both unoccupied and unfurnished at the time of our inspection. The weather conditions were dry and fine.
Challenges
The property was undergoing building works at the time of our inspection. This provides both benefits and challenges during an inspection. For example, visiting the property while it’s unoccupied and unfurnished allows our surveyors to fully access all areas of a property without being restricted by decorative features such as floor coverings or fitted units.
However, an active construction site also carries with it significantly more health and safety risks, not only to our surveyors, but also to any other tradesmen on site during our inspection. For example, access was restricted in certain rooms or areas due to the building’s condition.
Being aware of the situation before visiting, our surveyor liaised with our client prior to our visit to ensure the safety of all inhabitants within the building doth during our visit and later during remedial work.
Observations
Our surveyor first completed an external inspection of the building to assess its current condition. During this survey, our surveyor found that the building had not been maintained in an entirely watertight condition following initial works.
After discussions with our client, they highlighted that several external areas were to be renewed as part of the development project on the building. Content that the building would be rendered watertight again shortly to prevent internal dampness and condensation, our surveyor began their internal inspection.
Internally, our surveyor inspected the cellar, where they identified an active fresh growth of dry rot fungus (Serpula Lacrymans). A large fruiting body was confirmed on a wall underneath the ceiling boards, with several mycelia strands in the mortar joints. The spread was also identified within the ceiling above, with several timber beams and floorboards showing evidence of dry rot fungal spread. Some of the timbers also showed signs of cuboid cracking, a characteristic sign of fungal decay within affected timbers.
Dry Rot is an ever-present fungal organism, capable of germinating in damp conditions. Unlike its cousin Wet Rot, Dry Rot is especially hardy and resistant, and capable of spreading over masonry and behind plaster to find new sources of timber to feed from. This means that even if the source of moisture (such as a leak or penetrating damp) is treated, dry rot fungus can spread beyond the damp areas, taking over entire properties if left untreated.
Timberwise had visited the property previously to conduct treatment on a dry rot concern. As the dry rot had reappeared, our surveyor highlighted two likely conclusions: Either the property had not remained watertight, creating the ideal conditions for a new strain of dry rot to germinate and spread through the treated area, or the previous treatment had not been thorough enough, and some previously affected timbers had escaped treatment, allowing the previous strain to regrow.
In either case, with visual outbreaks of dry rot located just below the line of the ground floor timbers, there was an increased risk of upward growth, either behind dry linings in the walls or through the timber floorboards.
Solutions
Having seen the extent of the spread, our surveyor created a treatment plan to eradicate the new spread of fungal decay within the basement, and prevent transmission to the upper floors of the property.
To begin, our technicians first hacked off the remaining wall plaster in the cellar. This removed the fruiting body, as well as several strands of mycelia with it. The plaster was hacked off within 1 metre of any remaining strands, ensuring the spread was confirmed and removed prior to further treatment. As the spread was close to the ceiling, our technicians also removed a 1m band of plaster on the ground floor room above the fungal outbreak.
Once cleared, our technicians created a toxic box (cordon sanitaire) on the affected walls. This involved drilling several small holes at regular intervals, which were then filled with a fungicidal solution. This would create a protected area where fungal activity would be prevented from germinating and spreading.
In the timber floor, our technicians removed seventeen joists and one beam that each showed signs of fungal decay. In addition, three timber lintels above the ground floor windows were also removed and replaced, showing the extent of the spread from the cellar.
In each case, the timbers joists were replaced with new treated timbers. In the floor, the joists were also wrapped with a damp proof membrane where in contact with the masonry to prevent future moisture transmission.
In the case of the large timber beam, only a small section showed signs of significant decay. Instead of replacing the entire beam, our technicians instead cut out the affected material, splicing a new piece of timber into the beam. This beam was further strengthened with steel bars and epoxy resin, restoring the beam’s structural strength completely while retaining as much original material from the property as possible.
Once the repairs were completed, our technicians finalised the treatment plan by spraying each of the affected areas with a fungicidal solution. This would eradicate any remaining trace of fungal activity within the cellar or ground floor, and provide a final barrier of protection against future recurrence.
Results
Our client was satisfied with the works completed by our surveyor and technicians. Despite requiring a second round of treatment to completely resolve their concerns, our client was pleased that their dry rot issue had been successfully resolved. They were also pleased with our surveyor’s advice on maintaining the property in a watertight condition to ensure the effectiveness of these remedial works.
Do You Want Help with a Dry Rot Solution?
Our dedicated and experienced team in Leeds are ready to talk to you about your options for property preservation. Don’t hesitate to call us on 0113 208 9146, or you can request a survey online.
