Posts Tagged ‘Waterproofing’

Back to work, back to training!

Today some of our staff were retrained in First aid and we rolled out our online training program, starting with Health & Safety. We are hoping for a respite from lockdown by the spring, once Vaccinations have protected the vulnerable and alleviated the pressure on hospitals, but we are planning for Covid awareness and precaution for the long term, just in case it is the new normal. Training is one of the key principles for success so we have put all of our ongoing training online apart from the first aid ( you cannot kiss a virtual dummy ) and the practical training that requires hands-on learning like spraying waterproof coatings and applying products. Our staff are trained, Covid aware and we have the capacity for new projects of any size, which we can and will deliver promptly and professionally even in these difficult times.

Our MD Ian MacLennan is on the committee re-writing BS8102 Code of practice

MacLennan’s managing director has been invited to help re-write the BS8102 Code of practice for protection of below ground structures against water from the ground.

Why does this committee need consultant/contractors?

It is our site experience of hundreds of basement waterproofing installations per year and hundreds of investigations of sites, failures, issues that feed the industry with ideas for new products and new processes.

As a company that helps investigate it’s own and others mistakes in a specialist industry, to help come up with robust and sometimes unique ways to solve complex problems we are constantly learning, sharing and discussing these in-depth challenges & solutions to interesting problems. It’s what built our high-class team of specialists that can guide, advise and inform clients with a depth of knowledge that you cannot learn without our experience.

We provide hundreds of basement waterproofing solutions every year and the majority go without a hiccup but we’d be naive and in denial, if we weren’t aware that we work in the construction industry that is constantly evolving and has unique challenges each and every day. But this is also what allows us to be innovative and helpful in efficiently overcoming these stumbling blocks without holding up our client’s programs or compromising the watertight outcome. Access to our specialist skills is key when you are against the clock to deliver a project on time but also need to get the right detailing so you have no area of weakness in your complete waterproofing solution.

All this experience goes into every job we design each and every day, and this is what our  MD’s personal current contribution to the current & new BS:8102 advisory committee brings. As you cannot underestimate the value of a genuine specialist with the in-depth knowledge and experience to solve any problem that may come up, as well as having the capability to design & install you a waterproofing solution that is fully fit for purpose. Simplicity is often the key feature of someone at the top of their game as they see clearly what’s needed and quickly eliminate features that have limited value and come with higher risk.

That’s why a company that stands by its solution with a genuine guarantee for workmanship and the design is priceless in a high-risk industry as they are there to help remove your exposure to failure as they will always be there to help at every stage of the process, even after it’s completion. As it pays to never be complacent, always think through a design thoroughly, consider the clients budget to deliver value but without compromise, it’s buildability, to have the capability to communicate everything clearly and informatively. As to be a specialist consultant whether as an individual or a company comes with a responsibility that goes beyond a basic qualification but also covers the experience of the whole team that goes into delivering a full sub-contract package of works.

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.

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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.

Winter Deck & Roof Waterproofing Problems

Like all waterproofing and roofing contractors MacLennan have a tough time trying to apply waterproofing systems in Winter conditions.

Note to contractors, clients and project managers. If you are planning a roof or deck then do it in the spring / summer and hope it doesn’t rain.

All waterproofing and flat roofing systems require reasonable weather.

A responsible contractor will not even attempt to install if the temperature is below 5 degrees or if it is not 3 degrees above dew point. Relationships may be strained by a lack of progress on site, and then on the first day of reasonable weather every project manager will expect that they are next on the list for attendance, when in all likelihood a good busy contractor, will have a number of delayed projects and all for important , demanding clients who are desperate to complete their work and get there building dry. This is a problem shared by the whole industry, which leads to bigger problems when waterproofing contractors carry out installations in inclement conditions to keep the client happy, and then have a failure / leak as a result.

If you must programme work for Winter months remember the cost of a leak will be far more than the cost of a delay.


The golden rules are that work must not proceed unless :

  • Temperature 5 and rising Temperature 3 above dew point, no damp on surfaces.
  • Generally it is not possible to apply adhesives, primers, coatings for at least 24 hours after rain. It can appear dry and sunny but the dew point can still be very high in conditions of high relative humidity.

Remember if the contractor is not installing he is not earning, so he is just as motivated as you are.

MacLennan do have cement based systems for wet decks but not cold and Polyurethane systems for application when quite cold but not wet. Nobody has a system for cold and wet decks.

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