Posts Tagged ‘london’

JUNE Social Media Post Roundup

🔹Large Deck Over an Underground Car Park:

🔍 𝗦𝗶𝘁𝗲 𝗦𝘂𝗿𝘃𝗲𝘆 & 𝗪𝗮𝘁𝗲𝗿𝗽𝗿𝗼𝗼𝗳𝗶𝗻𝗴 𝗔𝘀𝘀𝗲𝘀𝘀𝗺𝗲𝗻𝘁
Our experienced surveyor recently visited this Bournemouth, mid-1970s purpose-built apartment complex comprising two 7-storey towers with a shared basement car park, to carry out a comprehensive inspection following reports of water ingress.
💧 𝗜𝘀𝘀𝘂𝗲 𝗜𝗱𝗲𝗻𝘁𝗶𝗳𝗶𝗲𝗱:
Water penetration was observed through the roof slab of the basement car park. The original deck was constructed using asphalt membranes, which are known to degrade under prolonged UV exposure. Over time, thermal expansion and contraction can lead to fatigue and cracking—especially at high-stress areas such as corners, structural junctions, and upstand details.

🔎 𝗞𝗲𝘆 𝗜𝗻𝘀𝗶𝗴𝗵𝘁:
It’s important to note that visible leaks on the underside of a concrete slab don’t always indicate the exact point of water entry. Water can migrate through construction joints, and movement joints before becoming visible below.
🏗️ 𝗦𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗮𝗹 𝗢𝘃𝗲𝗿𝘃𝗶𝗲𝘄:
The basement structure consists of reinforced concrete downstand beams supporting a 150mm thick slab. The ground-bearing slab includes perimeter edge thickenings and reinforced concrete walls to retain surrounding ground levels. Our inspection also highlighted the need for upstand and concrete repairs in several areas.
We’re now working closely with the client to develop a robust waterproofing solution tailored to the unique challenges of this buried deck system.

🔹Semi-Basement Extension, Salisbury: Following our pre-construction waterproofing survey, our technicians are now on site installing a 𝗧𝘆𝗽𝗲 𝗖 𝗰𝗮𝘃𝗶𝘁𝘆 𝗱𝗿𝗮𝗶𝗻 𝗺𝗲𝗺𝗯𝗿𝗮𝗻𝗲 𝘀𝘆𝘀𝘁𝗲𝗺 to protect the newly built semi-basement extension at this 𝗚𝗿𝗮𝗱𝗲 𝗜𝗜 𝗹𝗶𝘀𝘁𝗲𝗱 property in Salisbury.
Although not a full basement, the structure still requires effective protection against water ingress to ensure it remains dry and habitable—fully compliant with 𝗕𝗦 𝟴𝟭𝟬𝟮:𝟮𝟬𝟮𝟮 standards for below-ground waterproofing.

💧 𝗗𝗿𝗮𝗶𝗻𝗮𝗴𝗲 𝗦𝘁𝗿𝗮𝘁𝗲𝗴𝘆 – Gravity-Fed System:
As part of our design, we offered the option of a sump and pump system to manage any potential water ingress. However, the client opted for a gravity-fed drainage solution, which is a passive system that relies on natural fall to direct water away from the structure.

This approach involves:
✅ 𝗗𝗿𝗮𝗶𝗻𝗮𝗴𝗲 𝗰𝗵𝗮𝗻𝗻𝗲𝗹𝘀 integrated at the base of the cavity membrane system.
✅ 𝗣𝗶𝗽𝗲𝘄𝗼𝗿𝗸 𝗰𝗮𝘀𝘁 𝗶𝗻𝘁𝗼 𝘁𝗵𝗲 𝘀𝗹𝗮𝗯 designed with sufficient fall to ensure continuous flow.
✅ 𝗔 𝗻𝗼𝗻-𝗿𝗲𝘁𝘂𝗿𝗻 𝘃𝗮𝗹𝘃𝗲 fitted to prevent any risk of backflow from the external surface water system.

Gravity-fed systems are highly effective where site levels allow, offering a low-maintenance, energy-free solution for managing groundwater ingress.
We’re proud to support projects that combine modern construction with heritage sensitivity—delivering long-term protection and peace of mind.

🔹Cambridge House Walkthrough Video

🎥 Take a behind-the-scenes look at our installation work on the prestigious Cambridge House renovation project!

This video captures just a glimpse of the scale and complexity involved in transforming this iconic London landmark into a luxury 5-star hotel. With multiple phases and intricate detailing, it’s a project that demands precision, expertise, and collaboration—and we’re incredibly proud to be part of it.

From heritage preservation to cutting-edge waterproofing solutions, our team has been working closely with contractors and consultants to ensure the highest standards are met at every stage.

London Radon Protection

We're thrilled to be working with new clients on an incredible restoration and refurbishment of an existing house in London. This project includes the addition of a one-level basement that will feature a guest bedroom, gym, and utility room. 🏡✨

As local authorities become increasingly concerned about radon, we're seeing more projects that require radon protection measures. Starting from February 1, 2023, all new construction plots must have radon protection measures installed in accordance with updated mapping to comply with NHBC Standards and Building Regulations. 🛠️💧

While radon gas may not be as prevalent in London as it is in areas like the South West, it's still a significant concern for property owners. Radon gas can affect properties and their occupants across the UK, and it's important to be aware of this issue.

For more information or to discuss your project, contact our experienced team at enquiries@maclennanuk.com.

Bankside Yards West, London

Work progressing nicely at Bankside Yards West – a large commercial project we are working on. This incredible new tower is located along the South Bank of the Thames. The project reinvigorates a large and under-utilised site between Blackfriars Bridge and the Tate Modern museum, replacing two divisive blocks on either side of the mainline railway running north-south through London. The residential-led development combines housing along with offices, cultural and retail space as well as leisure amenities. MacLennan are waterproofing two basement levels of the Bankside Yard West tower. The design of a commercial basement, like with all basements, is critical and can be more challenging because of the mixed-use and often over several levels. Involving a specialist waterproofing company at the design stage for such (and any new builds) is critical.

Design meeting at MacLennan headquarters

Waterproofing, Better by Design.

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

Inspector allows two-storey Kensington basement despite policy limiting basements to one storey

A planning inspector has granted planning permission on appeal for the construction of a building with a two-storey basement in west London, despite an adopted planning policy restricting basement developments to one storey.

Planning
UK
Europe

The inspector decided that allowing the proposed development would not be contrary to the underlying aims of the relevant policy, which sought to keep the construction impacts on neighbouring homes to acceptable levels.

Sugar Bay Hill Limited (SBH) had proposed to construct a four storey building with two basement levels at the vacant site of the former Kensington Tavern in west London. Commercial uses were proposed for the ground and below-ground levels, with 13 homes to be contained on the upper floors. The Royal Borough of Kensington and Chelsea decided to refuse permission for the scheme in January. The Borough had adopted a core strategy policy seeking to limit basement developments to 50% of the open part of any development site and for basements not to comprise more than one storey. In an appeal decision dated 18 September (9-page / 163 KB PDF), planning inspector Peter Rose said he attached significant weight to existing planning permissions for the site which allowed for the same amount of excavation at basement level as the appeal proposal. Rose noted that the only additional excavation that would take place under the appeal scheme would be a small lower basement area and that SBH had provided evidence that this additional excavation would add a maximum of 17 further days of work across a two-year construction period.

The inspector was satisfied that the proposed development “would not significantly harm the living conditions of neighbouring occupiers during the construction period” and was not, therefore, contrary to the underlying aims of the Borough’s basement development policy. Rose considered that the impacts of the development would be “outweighed by the overall net benefits of the scheme”. He noted that, compared to the proposals for the site that had already received permission, the appeal scheme would have greater benefits “with regard to housing and townscape” and offered more beneficial use on its upper floors thanks to the additional lower basement space for commercial uses. Planning expert Victoria Lindsay of Pinsent Masons, the law firm behind Out-Law.com said: “The construction impact on neighbouring residents and homes from basement development is a key concern for London boroughs at the moment, particularly in the Royal Borough of Kensington and Chelsea which is consulting at the moment on a draft Code of Construction Practice. The consultation draft Code of Construction Practice seeks to impose greater controls on hours of construction work and audible noise levels. The Borough is also looking at introducing an Article 4 direction in April 2016 to withdraw permitted development rights for basement development works.”

“Although this appeal decision grants planning permission for a two-storey basement contrary to adopted planning policy, it cannot be taken as a precedent for two-storey basements in the future across the Borough,” said Lindsay. “The inspector clearly placed a great deal of weight on the extant planning permissions for the site permitting the same amount of basement excavation as the appeal proposal and decided that there would be no significant additional construction impact over a two year construction period. Therefore, the purpose of the policy, seeking to keep construction impacts on neighbouring homes to acceptable levels has not been hindered.”

“This appeal decision helps to focus minds on how basement policies should be applied and properly interpreted,” said Marcus Bate, another planning expert at Pinsent Masons. “The size of a proposed basement can be given too much weight in isolation. What really matters is whether the impact on neighbouring living conditions is acceptable. The Inspector rightly recognised that this was the only way to reach a proper balanced judgment in the case.”

Ian MacLennan
CSSW CSRT