Case Study: Addressing Moisture Ingress and applying a Waterproofing solution

Client: Private

Property Address:  Cirencester area

Inspection Date: August 2024

Contractor: Cannon Clarke Ltd

Project Overview

We were invited by our client to inspect and provide recommendations for the lower ground area of a property originally built and used as a Lock Keepers House. The property, circular in shape, is situated alongside an old canal.

Background

The property features a lock run-off designed to manage high water levels by channelling excess water from the canal into a drainage ditch. However, the canal now runs dry during summer, and the drainage ditch is no longer maintained. During winter, the canal fills to capacity, causing water to pond over the front gardens and eventually seep into the ground floor, which is approximately 300mm lower than the external ground levels.

Existing Issues

So we could address water ingress, two pumps were installed in a concrete box. However, this solution has proven inadequate due to:

• Water entering from the wrong side of the room, filling the floor area before reaching the pumps.
• The pump house not being watertight, causing the pumps to activate unnecessarily when groundwater rises.

Recommendations

We proposed the following solutions to effectively manage water ingress:

1. Water Management System: Install a water management system to full height.
2. Tile Lifting and Re-laying: Lift the existing tiles, which could potentially be re-laid following our works by others.
3. Double Pump System: Install a double pump system to enhance water removal efficiency.
4. Cavity Drain Membrane (CDM): Fit a CDM to the floor and walls to prevent water ingress and manage moisture effectively.

Works Carried Out

• Floor Tiles: Removed floor tiles and set them aside for re-use.
• Step Removal: Removed the step into the hallway.

• Wall Plaster: Removed wall plaster.

• Water Testing: Conducted water tests on the floor.
• Channel Cutting: Cut channels as required.
• Old Pumps: Removed old pumps.
• Sump Pit: Dug out for the sump pit.
• Pump Chamber: Fitted the pump chamber.
• Outlet Pipe: Dug out for the outlet pipe.
• Pump Installation: Fitted the pumps.

• Floor Membrane: Laid 20mm membrane over the floor.
• Wall Membrane: Installed 8mm wall membrane to the walls full height.

• Wall Battening: Battened the walls.
• Plasterboard and Skim Finish: Applied plasterboard and skim finish.

• Concrete Floor Slab: Laid a new concrete floor slab.
• Step Reinstatement: Reinstated the step.
• Site Cleanup: Removed all rubbish and debris from the site, leaving the treatment area clean and tidy.
• Guarantee: Provided an industry-standard 10-year Structural Waterproofing Guarantee.

Outcome

Implementing these recommendations and carrying out the specified works will significantly reduce water ingress giving additional protection to the property from water ingress and ensure a dry and habitable lower ground area.