Oatley House, Bristol

Client: St Monica Trust

Project Overview

Oatley House, Bristol

650 m²

Service: Roofing

Sector: High-rise flats

  • Approved Contractor: MLG UK Ltd
  • System Installed: Polyroof Protec Evolve cold-applied liquid membrane
  • Client: St Monica Trust
  • Duration: Two four-week phases, with a break between them
  • Work Carried Out: Cold-applied liquid overlay, recovery layer, bespoke leadwork, ProGrip walkways

Scope of Work

Seventy apartments, a Grade II listed care home built in 1925, and 650 m² of asphalt roof that had stopped keeping the water out. The roof was replaced across two phases with residents in their homes throughout.

  • 650 m² across the main house and reception roofs, delivered in two four-week phases
  • Core testing confirmed the existing build-up: felt, asphalt, insulation and concrete deck, was suitable for overlay, eliminating the need for full strip-out
  • 25mm Polyroof Tissue-Therm recovery layer to normalise the substrate
  • Polyroof Protec Evolve cold-applied liquid membrane throughout
  • Timber upstands hand-built to accommodate historic stonework, finished with lead flashings
  • Polyroof ProGrip Anthracite Grey walkways for safe maintenance access

Systems installed

  • Waterproofing: Protec Evolve: cold-applied, ultra-low-odour liquid membrane with RapidCure technology (Polyroof)
  • Recovery layer: 25mm Tissue-Therm to normalise the substrate (Polyroof)
  • Carrier: Foil-faced carrier layer (Polyroof)
  • Walkways: ProGrip Anthracite Grey anti-slip walkways (Polyroof)
  • Flashings: Lead flashings to hand-built timber upstands

Challenges & Constraints

01
Residents in their homes

Oatley House is a Grade II listed care home built in 1925 with seventy apartments, and the residents stayed in occupation across both phases of the work.

02
Intricate listed detailing

Crenelated sandstone parapets and undulating surfaces prohibited full encapsulation or invasive intervention on a listed building.

03
Traditional methods ruled out

Torch-on felt carried fire risk and mechanically fixed membranes meant disruptive removal of existing materials, and both would have pushed odours through an occupied care setting.

Project Execution & Techniques

Core testing first

Core testing confirmed the existing build-up of felt, asphalt, insulation and concrete deck was suitable for overlay, which eliminated the need for a full strip-out.

Cold-applied, ultra-low odour

Protec Evolve was applied cold over a 25mm Tissue-Therm recovery layer that normalised the substrate, so installation was safe with residents in place.

Cure controlled both ways

RapidCure technology let the membrane polymerise quickly enough to work around heavy rain, while summer inhibitors controlled cure times through high temperatures.

Upstands built to stone

Timber upstands were hand-built to accommodate the historic stonework rather than standardised, and finished with lead flashings.

Outcome & Long-Term Benefits

Fully bonded waterproofing

650 m² of failing asphalt was replaced with a robust, fully bonded and durable waterproofing system that futureproofs Oatley House while respecting its Grade II listed status.

Minimal disruption to residents

Residents experienced minimal disruption thanks to the overlay approach, the low-odour formulation and controlled scheduling.

Safe maintenance access

ProGrip Anthracite Grey anti-slip walkways give safe access for future maintenance in a colour chosen not to spoil how the roof looks.

Highly Commended, LRWA 2026

Highly Commended for Liquid Waterproofing Project of the Year under 1,000 m² at the LRWA Awards 2026, and published as a case study by both Polyroof and the LRWA.

Conclusion

Seventy apartments, a Grade II listed care home built in 1925, and 650 m² of asphalt roof that had stopped keeping the water out. Everything about the method followed from one constraint: the residents were not moving out, and the crenelated sandstone parapets and undulating surfaces would not accept invasive intervention.

Core testing proved the existing build-up could be overlaid, which removed the strip-out, the waste and the noise. A cold-applied, ultra-low-odour membrane made installation safe above occupied accommodation, RapidCure and summer inhibitors handled rain and heat, and timber upstands were hand-built to the historic stone. The £201,055 job ran across two phases and was Highly Commended at the LRWA Awards 2026.

"I've engaged MLG for several large-scale roofing projects with varying challenges, and have always found them proactive and responsive. Projects are completed on time and on budget, and they're always sensitive to the live nature of our buildings. I look forward to using them again."
, Mark Essex, St Monica Trust

Ready to start your project?

Contact MLG UK today.

Get your quote now