Client: Housing Association
Our client, a housing association, contracted Timberwise to survey their property for a suspected dry rot fungal outbreak within the basement. This property was previously a school building, but had been converted into flats. The property was of brick construction, and was occupied during our visit. The weather was overcast and wet.
Observations
Our surveyor first completed an external inspection of the property, where several previous defects had recently been repaired.
Algae growth was identified around repaired rainwater pipes and guttering. This suggested that there had been a historic leak or blockage around the pipes, which would have fed the algae and encouraged its growth.
Perished mortar joint pointing and vegetation growth were identified further down the wall. Defects such as these indicate areas where moisture could ingress within a property. If water had previously been able to run down the wall from the faulty rainwater goods, this could be a possible contributor to conditions within the property.
Water ingress is also a valid concern due to the nature of the property’s construction. Our surveyor discovered that the building was primarily constructed with single leaf walls.
These are more prone to rainwater penetration and condensation, as there is only one layer between the outside and inside wall. This means that any moisture can ingress directly into wall plaster, and condensation can build up more easily as the wall is often colder when compared with a modern cavity wall construction.
Internally, Dry Rot fungal decay (Serpula Lacrymans) was identified in the lower ground basement level of the building. The cause was believed to be the recently repaired rainwater pipes and guttering, which had contributed a steady supply of water for the Dry Rot to feed on.
Dry Rot fungus germinates when moisture levels within timber reaches 20%. However, Dry Rot is also not attached to its source, and will often spread along plaster or masonry to find other moisture sources. It can even lay dormant until the ideal conditions for its growth are met. Fruiting bodies from the fungus were found on several surfaces within the basement, indicating that the fungus had been growing for some time prior to our inspection.
In a separate inspection, our surveyor was also asked to diagnose a further issue within one flat which was located several levels above the basement floor. Within, the windowsill was cracked and flaying. Our surveyor believed this to have had a historic issue, but it could not be confirmed whether this was dry rot spreading from the basement level, or a wet rot issue from a previous leak, either within the window frame or from the rainwater goods above.
Solutions
In cases of Dry Rot, the only truly effective remedial method is removing all affected materials within the area of infestation. As Dry Rot fungus is particularly hardy and able to lie dormant, leaving any amount of fungal material could allow the infestation to strike again, especially if a future leak were to create the ideal conditions for germination. As many of the external defects had been repaired previously, it was down to our team to recommend the ideal treatment to remove the dry rot infestation within the building.
To begin, our surveyor recommended removing all timber materials within the affected area, including window frames, timber frame walls, floorboards, and windowsills. All removed materials would then be passed on to our client’s preferred tradesmen to create replacement timbers to replace these once treatment had concluded.
Once removed, a toxic box would be created around the affected areas. This involves drilling small holes into the surface of the wall around any timber fixtures. These walls are then injected with a fungicidal solution which would prevent any future rot from spreading beyond this protective barrier.
Finally, any remaining undamaged timber would be treated with fungicidal gel. These timbers could then be returned to their original positions, and either capped or laid on a protective membrane to prevent future damp issues.
As a final preventative measure, our surveyor also recommended clearing the brickwork of paint and spraying a fungicidal solution to remove any remaining fungal material from the prior treatments. As Dry Rot can spread along masonry and plaster to find new moisture sources, this would ensure that any possible remaining material would be eradicated, especially if any were left underneath the existing paint and plaster. As it is also possible that the infestation could have spread beyond the basement, our surveyor also recommended performing checks periodically on the ground floor flats to ensure any spread was controlled and removed if found later.
Results
Our client was grateful for the professionalism of our surveyor, and highlighted their diligence in providing a solution that not only treated the immediate area, but also prevented future ingress into the other properties within the building. Our client also praised our ability to work with their own preferred tradesman to provide the ideal remediation work to return their property to its former condition.
Do You Want Help with a Dry Rot Solution?
Our dedicated and experienced team in Preston are ready to talk to you about your options for property preservation. Don’t hesitate to call us on 01772 471 375, or you can request a survey online.
