Sept & Oct Social Media recap

🏗️ Project Update: Prestigious New Development in St John’s Wood, London 🏡

We’re proud to be part of this high-end residential project in St John’s Wood, where the transformation involves the demolition of an existing property and the construction of a stunning new home designed to the highest standards.

📍 Our team is making great progress with the cavity membrane installation in the expansive basement. With multiple levels to work through, our skilled technicians are now focusing on the upper sections, ensuring every detail is executed with precision.

This is a complex and exciting build, and we’re thrilled to see it taking shape. Big thanks to our dedicated team on site, your hard work and expertise are driving this project forward!

🔧 Project Spotlight: Haslemere Swimming Pool Basement 🌿

We’re proud to be delivering the full waterproofing package for a luxury basement swimming pool in Haslemere, complete with changing rooms, kitchen, and dining area.

💡 Waterproofing Highlights
This fully buried structure sits beneath a landscaped garden and green roof, demanding zero tolerance for water ingress. Our solution includes:

Crystal Coat: Cementitious crystalline slurry applied to internal walls and slab to block capillary paths.
Type C System: Cavity membrane, perimeter drainage, and twin pump system with battery backup — all compliant with BS 8102:2022 Grade 3.

🧪 Deck Protection
Above the basement, we applied our PolyM liquid waterproofing membrane , a seamless, flexible coating that resists root penetration and accommodates movement, ideal for green roof applications.

🛠️ Installation is near completion almost, ready for the next phase,

We’re proud to be contributing our specialist waterproofing expertise to the restoration of the historic 20th Century Theatre in London, a venue soon to be revived as a vibrant space for music, dance, and stage productions.

Our experienced surveyor has designed a bespoke internal waterproofing system tailored to the unique requirements of this heritage building. The system includes:

Application of a lime inhibitor to the internal walls and floor surfaces, which helps neutralise the high alkalinity often found in lime-based substrates, ensuring compatibility with modern waterproofing materials.
Installation of a cavity drain membrane system, which manages water ingress by directing it to a controlled drainage point, preserving the integrity of the structure while maintaining breathability, essential in older buildings.

Once complete, the space will be warm, dry, and protected, ready to be restored to its former glory and enjoyed by future generations.

Our in-house aftercare team will arrange regular system checks and maintenance, so the client will always be cared for by us,

Data Centre Waterproofing – Oct Newsletter

Waterproofing in Data Centre Construction: A Critical Risk Management Strategy

With the surge in demand driven by AI and recent deals with major US tech giants, the data centre market is set to expand rapidly. But with growth comes risk—and waterproofing is one of the most critical yet overlooked aspects of data centre construction.

Why Waterproofing Matters

Water ingress, moisture migration, and gas penetration are among the most common causes of construction delays and post-completion failures. These issues can lead to costly downtime, especially for data centres where uninterrupted operation is essential. Main contractors risk millions in liquidated damages if waterproofing fails during or after construction.

Data centres require precise environmental control. Even minor leaks or humidity spikes can compromise sensitive equipment, delay commissioning, or breach service-level agreements.

That’s why compliance with British Standards and the Building Safety Act isn’t just a statutory requirement, it’s a vital safeguard for the design team, contractor, and client.

The Myth of Manufacturer Guarantees

British Standards (BS 8102 for waterproofing and BS 8485 for gas protection) and the Building Safety Act demand rigorous design and installation practices. Manufacturer guarantees alone do not meet these standards. In fact, no successful claims have ever been made against a manufacturer’s waterproofing guarantee, liability always falls on the installer. If you're not using a specialist waterproofing contractor with appropriate insurance, you don’t have a valid guarantee, and you’re not compliant, regardless of what the manufacturer promises.

Key Compliance Requirements

To meet British Standards and mitigate risk, the following must be in place:

Waterproofing design must begin at RIBA Stage 2, led by a qualified waterproofing design specialist
A Golden Thread of information must be maintained throughout the project lifecycle
All works must be carried out by trained, insured specialists with a minimum of £10 million Professional Indemnity (PI) cover
Service entries must be designed and installed early to ensure gas and water tightness from the outset
Gas protection is mandatory for most below-ground structures, especially in brownfield or contaminated sites
Inter-floor waterproofing and service penetration detailing must be handled by specialists to avoid weak points in the structure.

Only a specialist design-and-install company with a proven track record and genuine guarantees can deliver fully integrated waterproofing and gas protection systems.

Why MacLennan?

MacLennan has successfully delivered thousands of below-ground projects, including complex multi-storey basements in challenging environments. Our credentials include:

Full design liability backed by extensive experience
Insured long-term guarantees on workmanship and materials
Integrated systems combining structural waterproofing and gas protection
Qualified, experienced, and insured installers

Unlike manufacturers, MacLennan takes full responsibility for design, supply, and installation using our own trained staff. Our designers have real-world site experience, something manufacturers lack, often resulting in impractical or flawed designs.

We can demonstrate zero basement waterproofing failures across 200+ projects annually. Manufacturers can’t make that claim because they don’t install or guarantee the work.

Ongoing Support & Monitoring

MacLennan offers:

A dedicated aftercare department with qualified electricians for pump and backup system servicing
Remote monitoring services for critical components like batteries, floats, and alarms, alerting you to potential issues before they become problems.

Contact our technical design team today to take the risk out of your data centre waterproofing.

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Archive for October, 2025