Two Property Conservation vans parked outside a period home in Coleshill, suffering damp and mould due to elevated external ground levels
Two Property Conservation vans parked outside a period home in Coleshill, suffering damp and mould due to elevated external ground levels

Location: Coleshill, Swindon

Type of property: Solid stone construction, with slate roof

Services used:

  • Free non-invasive damp survey and report
  • Installation of dampproof mesh membrane – guaranteed for ten years
  • Plastering – guaranteed for ten years
  • Carpentry
  • Ground excavation
  • Installation of Geo-Drain
  • Referred electrician

Materials Used: 

  • 3mm Delta Mesh Membrane
  • Natcem mortar
  • British Gypsum plaster
  • Treatment for existing skirting boards
  • CTB fan (Constant Trickle & Boost)
  • Delta Geo-Drain Quattro 9mm membrane
  • 20mm shingle

Problem:

Black mould and dampness evident on kitchen wall surfaces. Upon inspection using an electronic moisture meter, elevated readings were recorded up to an average height of 2m from internal floor level.

Identified cause to be lateral water ingress from elevated external ground levels 100-150mm above internal floor level, with no evidence of dampproof course. Identification backed up by discolouration of wall surfaces from hygroscopic ground salts, and presence of mould.

Our surveyor noted the presence of a PIV (Positive Input Ventilation) unit in the kitchen with no source of mechanical extraction installed, thereby creating an imbalance of heating and ventilation, a likely cause of condensation, mould being symptomatic of this.

Works completed: 

To remedy the internal wall conditions, we removed the skirting boards and wall plaster 50mm in height from the internal floor level.

3mm Delta Mesh Membrane was installed from floor to ceiling over the existing wall plaster (taken down 60mm below the flooring stones, sealed with Natcem for damp proofing.

We then installed new plasterboard or lightweight backing depending on wall depth which was replastered with British Gypsum plaster before the reinstatement of newly treated skirting boards ready for decoration by others.

With regard to the elevated ground level, we excavated the ground at the base of the walls 300mm in depth and 300mm in width.

Geo-Drain Quattro from Delta was installed as seen in the photographs marked green, and the trench backfilled with 20mm shingle for a pleasant aesthetic finish.

To aid future ventilation of the kitchen we appointed a trusted electrician to install a heat recovery fan (CTB) which as wired into a fused spur.

Before

During

After

Property Conservation Services Treatments