Portman Square London Inverted Roof Refurbishment
- Project
- 40 Portman Square, London
- Structure
- Luxury Residential and Commercial Offices
- Client
- Portman Investment Unit Trust
- Contract
- Inverted Liquid Roofing Refurbishment
40 Portman Square is a prestigious development by architects Squire and Partners and located in Marylebone, Central London. It offers in excess of 100,000 Sq. Ft of office and commercial space.
It’s also home to twenty luxury residential apartments on one of London’s most prominent squares. The building offers floor to ceiling glass with stunning views over Portman Square and the sixth floor has an impressive terrace that spans the length of the building.
Triflex ProTect Liquid was chosen to replace failing waterproofing systems on the plant roof, perimeter roof and fifth floor balcony. Each system had reached the end of its life.
Initial investigation showed that each roof would need stripping back to the concrete substrate and at this time tapered insulation was utilised to upgrade the thermal performance and provide an artificial roof slop and eliminate ponding water. Triflex ProTect Liquid system was selected for its versatility and ease of use on site
With the building remaining fully operational and occupied throughout, the programme challenged Makers to produce the usual high standard of workmanship. Material access was strictly on a timed basis via basement and car lifts.
The central roof housed a large amount of plant that was servicing the entire building. With the programme running through the winter and the requirement for the plant to remain active, a new temporary roof was installed to keep the plant watertight and ensured the programme remained on time and without delay.
Makers developed their own block and tackle system and material sliders to lift and move the live plant. This allowed the heavy plant area to be fully stripped and new system installed. Prefabricated galvanised sheets were manufactured, T-washed and treated before applying the Triflex ProTect waterproofing system. With the plant raised off the deck, the systems were then slid under the plant support system. The coatings could then be increased and overlaps built up.
The main roof perimeter had a failing membrane and upstands. This was stripped back to the concrete substrate, cleaned and primed and all rainwater outlets refurbished and dye tests completed. The thermal performance was improved to achieve required 0.18 w/m2k with new taped insulation installed before the final liquid waterproofing applied.
The inverted fifth floor roof was also stripped back to concrete deck, substrate cleaned and primed and further dye tests completed on the rainwater outlets. The new taped insulation installed with pavers replaced and all lightning conductors reinstated. All new handrails installed across the project to insure safe practice on future roof inspection. This project demonstrates Makers Constructions ability to adapt to any working condition however difficult the access or existing roof build up. The project delivered the client a 20-year waterproofing warranty, piece of mind and protection.
