Client: Property Developer
Our client, a property developer in London, tasked Timberwise with surveying a property following a recent plumbing leak. We had previously visited this property in 2022 to install a basement waterproofing system, which had protected the property from extensive damage. This property was a house of solid brick construction, and was both occupied and furnished at the time of our inspection.
Challenges
Prior to our most recent visit, the property was occupied, and the basement had been converted into a lounge room with a small gym. The presence of furnishings, as well as fitted floor coverings, can make it difficult to completely diagnose an issue. As the property had been visited previously, our surveyor was already familiar with the property’s layout, as well as where previous defects had been identified, and this helped to coordinate the new survey and ensure a thorough investigation into the cause of the new water damage was conducted.
Observations
We had previously attended this property after our client’s basement had flooded. After a partial strip-out, several defects were identified around the window reveals, as well as within the wall linings, which had not been properly sealed. This had caused moisture ingress through both the walls and window linings, which passed through the defects and into the interior of the room, causing the flooding. Our technicians installed a replacement waterproofing system, including a new sump pump, cavity wall membranes, and drainage channels to divert any future floodwater off site.
Unfortunately, our client had asked us to re-attend recently after a suspected plumbing leak in a bathroom above the basement. Our surveyor began by investigating the basement room, where they noticed a large area of failed plaster on one wall. Our surveyor assessed this wall with an electronic conductivity meter, which returned with a moisture content of 73%. While this reading is only an indication of damp on masonry or plaster, the high level indicated that the leak had likely passed into the wall from above, bypassing the existing cavity drainage membrane from above the basement wall.
However, while the wall showed extensive damage, there was a silver lining. Upon inspecting the existing sump pump, our surveyor noted that the alarm had triggered, alerting the client to a flood within the pump. After testing the pump through a jetting port, our surveyor found that water flowed without issue. Our surveyor concluded that most of water from the leak had flowed behind the membrane from above. Because of this, our client evaded the risk of extensive damage to the high-value finished rooms.
Solutions
As the recent damage was minimal, and isolated to a single wall, it was a simple procedure to restore the basement to its former condition.
First, our technicians removed the water damaged plaster from the wall to assess the condition of the cavity drainage membrane beneath. After assessing the membrane, they found that it was sound, and had no punctures or defects. They further tested this by pouring a small amount of water behind the membrane, which did not pass through, and instead collected in the wall channel at the base of the wall as intended.
Once the membrane’s condition was confirmed, our technicians reinstated it to the wall, and re-sealed the connection to the adjacent membrane sheets to restore this layer of protection. Our technicians then resurfaced the membrane with a salt retardant specification plaster, which would prevent atmospheric moisture from building up in the interior wall plaster in future. This could then be redecorated to match the remainder of the room once the plaster was dry.
The team then completed the work by resetting the sump pump, clearing the flood error message on the alarm system, and testing the entire system to ensure it was again working as expected.
Results
Our specialist team successfully diagnosed and remedied the flood issue, confirming that the previously installed system was working as intended. The basement was restored to a habitable state, and our client was relieved that the system had prevented large-scale damage within the basement. This also proved the effectiveness of the pump protection system, ensured damage to the finished rooms was minimal and remedied swiftly.
Do You Want Help with a Waterproofing Solution?
Our dedicated and experienced team in North London are ready to talk to you about your options for property preservation. Don’t hesitate to call us on 020 8226 6486, or you can request a survey online.
