Posts Tagged ‘Blog’

How To Prevent Basement Waterproofing Failures

June 2025 Newsletter

June 25 newsletter

Basement waterproofing failures cost the UK construction industry millions of pounds every year—not just in repairs, but in project delays, reputational damage, and client dissatisfaction. The most frustrating part? These failures are entirely preventable.

At MacLennan, we’ve spent decades refining our approach to waterproofing design, installation, and maintenance. In this post, we’ll explain how we prevent failures before they happen—and why our systems are trusted across the UK and beyond.

It All Starts with Smart Design

Most waterproofing failures can be traced back to one root cause: poor design. At MacLennan, we believe that good design is the foundation of waterproofing success. But we’re not just talking about detailing—we mean integrating the installation process, maintenance strategy, and repairability into the design from day one.

The British Standard and all major codes of practice are clear: waterproofing systems must be designed with repair and maintenance in mind. Yet, many systems are installed without any consideration for how they’ll be accessed or serviced once finishes are in place.

🧱 Why Type C Systems Are the Gold Standard

If your basement includes finishes, internal walls, or linings, then only a Type C cavity drain system can provide the level of repairability required for long-term performance.

Unlike other systems, Type C solutions are designed to manage water ingress by directing it to a controlled drainage system. But even these systems can fail—if they’re not properly maintained.

🔍 Inspection & Servicing: The MacLennan Difference

Most service providers focus on pump maintenance, but the real Achilles heel of a cavity drain system is the drainage channel. If this becomes blocked or compromised, the entire system is at risk. At MacLennan, we’ve solved this with:

  • We design and manufacture our own inspection ports, allowing directional camera access for full visibility.
  • We commission and inspect the system after finishes are installed—when many issues first appear.
  • We provide ongoing servicing through our dedicated in-house team, ensuring long-term performance.

📡 Remote Monitoring & Superyacht-Grade Reliability

We’ve taken it a step further with remote monitoring technology built into our systems. This allows us to track performance in real time and alert clients to potential issues before they become problems.

And when it comes to power reliability, we use state-of-the-art battery backups and inverters—the same systems trusted on ocean-going superyachts. These can even be upgraded to power essential services during outages.

🛠️ Servicing Is Not Optional—It’s Essential

You wouldn’t buy a car and never service it. A waterproofing system is no different. Regular maintenance is the key to preventing failures, and it should be built into the design from the start.

At MacLennan, we don’t just install systems—we design them for life.

💬 Want to Learn More?

We’re passionate about helping clients avoid costly waterproofing failures. If you’re planning a basement project or want to ensure your current system is protected for the long haul, get in touch with our team.

MacLennan raise money for charity

MacLennan raise money for charity

Here at MacLennan waterproofing, we have been helping raise money and awareness to a local, Wiltshire charity, Julia’s House. So far, we have raised £208.67 to this wonderful charity who, provide essential respite and care for seriously ill children.

Back in 2016 we installed a much-needed damp proofing system to the Charity’s care home in Devizes. Our work not only safeguarded the building against water ingress and damp issues, it also ensured that the children could continue to stay in their familiar surroundings.

You can read the full case study from that project here: https://maclennanwaterproofing.co.uk/case-studies/damp-proofing-case-study-julias-house-hospice-devises/

MacLennan raise money for charity

We will continue to support and raise money for this amazing charity. If you would also like to donate, you can do so via their website:

https://www.juliashouse.org/appeal/christmas-appeal-addys-story?utm_source=homepage&utm_medium=donate_button&utm_campaign=christmas_appeal

Safe Contractor Accreditation

Safe Contractor Accreditation

We’ve done it again! MacLennan Waterproofing are proud to announce that we have successfully renewed our Safe Contractor accreditation for another year!

Safe Contractor Accreditation

So, what does this mean to you and your clients?

  • This will give you peace of mind that we are a safe company to use
  • We are committed to continuously improving health & safety standards
  • We are committed to sustainable and ethical practices
  • We work compliantly in line with all current regulations

Maclennan take the risk out of waterproofing. Protect your client, protect your project, give us a call for design and installation with no split liability 0330 3200 240

Design meeting at MacLennan headquarters

Waterproofing, Better by Design.

ian scroggins

Ian Scoggins CSSW

I have worked in the construction industry for 28 years and have been specialist waterproofing surveyor for 12 years, my time as a waterproofing specialist has given me a rounded experience of the industry.

During that time in the industry, I have seen projects that have gone very well and some not so great.

Based on my personal experiences, I have come to realise that its early engagement and collaboration with the overall design team that delivers the best results. By everyone investing time in early engagement, I find that designs can often be simplified as sitting around a table and everyone giving their input can often take out expensive complexity and give a much better overall solution, that ultimately benefits the end client.

This only works when the correct sub-contractors are engaged on project early, so they are associated with the project from day one, one thing that sets us apart from manufacturers offering technical support is that we are involved in projects on-site every day and know the practical solutions to problems that aren’t always evident when looking at a drawing.

When it comes to high-risk elements like the basements and waterproofing, going out for multiple tenders and the lowest bidder often leaves you with skills and scope gaps as there is a clear lack of ownership. It can then become about delivering a solution to a budget, rather than a simple but effective solution that works with all the other key partners on the project in mind that’s actually deliverable on-site.

This doesn’t mean the client shouldn’t benchmark the competition and capabilities, as I live in the real world and want to offer real value for money to my clients but I want to do this without them un-intentionally building in unnecessary risk by accident by being insightful and helpful early on. It’s what falls between the cracks where the real risks sit (no pun intended) that really sets out your specialist subcontractor as part of a collaborative team that makes all the difference.

"My role is as much about sleeping well at night, as it is about waterproofing."

As myself, my MD, our insurance company, the main contractor and my end client all want to never ever worry about what the waterproofing is doing as it’s a hidden system in their beautiful property that just does what its supposed to. Its why our company takes full design and solution responsibility and hold genuine guarantees as we offer our clients leak free basements from a waterproofing perspective rather than material warranties.

If you found this blog helpful or would like to hear more technical advice, try booking a CPD with MacLennan! We offer free, lunch provided 1 hour CPD's at your premise.


CPD Booking Form

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maclennan waterproofing spray

Deck hunting season is open!

The MacLennan staff are starting to emerge from the basements, blinking in the sunlight and preparing to work on decks. Winter work on basement decks is at best difficult and at worst, carried out incorrectly in poor conditions.

Sprayed and hand applied liquid Waterproof systems should never be applied on damp decks. They should never be applied when the ambient temperature is not at least 3 degrees above the dew point, even if the sun is out. We rely on bond to resist outgassing.

This applies to most forms of waterproofing on decks and around basements. Even the sheet membranes normally have a primer which relies on the dry warm conditions for installation.

Planning a basement.

If you are planning a basement you should be sequencing the work so as the critical deck and external waterproofing is carried out in the spring, summer and early Autumn.

If the work has to be carried out in the winter then you have to cost in Winter primers, tenting, frost blankets, installing and removing covers, drying of surfaces and downtime when work just cannot happen unless fully tented and heated.

All of this preparation is very rarely considered even when set out in supporting information and data sheets supplied by contractors and manufacturers.

This is all critical.

If you allow or worse force the work to happen in inappropriate weather and environmental conditions you will have failures.You cannot apply waterproofing the day after rain, you need at least a good days drying after the water has been cleared off of the deck.

Get in touch!

Ready to start a project or require more information about us?
Call us about your project or problem and we will be happy to help.


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0330 3200 240
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