Shell Tower


Structural Renovations Shell Tower

Structural Renovations have recently been carrying out waterproofing works in various locations within the Shell Centre in Central London.

Our works have involved controlling water ingress within the basement and lift pit areas of the main tower.

The 27 storey tower and 3 (now demolished) 9 storey wings were constructed between 1957 and 1962, on part the site used for the Festival of Britain. At the time the tower was the tallest building in the UK and the largest office building, by floor space, in Europe.

Our first phase of works involved pouring a new screed, laid to falls, within a double width lift pit using Flexcrete Fastfill repair mortar, modified with kiln dried quartz sand. The screed and 150mm of the adjacent walls were then waterproofed using Flexcrete Cemprotec E942, a cementitious waterproof coating, prior to the lift engineers reinstalling the lift buffers and rails.

The second phase of works to 2No. adjacent lift pits was based upon a bespoke waterproofing solution designed by Parkinson VTC Ltd. The works involved the installation of a wire mesh box around both sumps within the lift pits, prior to the installation of a 400mm thick layer of 10mm aggregate, to act as a soak away. A 450mm thick layer of Flexcrete Fastfill modified with 10mm aggregate was then installed over the soakaway. The screed and 150mm of the adjacent walls were then waterproofed using Flexcrete Cemprotec E942.

The limited space on site and strict delivery periods meant that up to 4 tonnes of material were being mixed and laid by hand each day.

A major redevelopment of the area, involving new office, retail and residential space has transformed the site and 1,700 Shell staff, who were temporarily relocated to Canary Wharf, have moved back to inhabit the main tower.

Enderby House, Greenwich


Structural Renovations Enderby House

The site was first developed in the 1830s by the firm Samuel Enderby & Sons, who were the largest commercial whaling and sealing company in Britain. The Company was so famous at the time that Hermann Melville immortalised the Enderby family in his book ‘Moby Dick’.

Enderby House was built in 1846, as both a home and office premises for the Company, until the decline in whaling led the Enderby’s to cease their enterprise in 1854.

Glass Elliott & Co. took over the site to manufacture and lay transatlantic telegraph cables. It is interesting to note that the SS Great Eastern was used as a cable laying ship due to its sheer size being capable of holding the required amount of cabling. Numerous takeovers and mergers took place over the years and the last cables were manufactured on the site in 1975. The communications company Alcatel, who purchased the site in 1994, eventually sold a large part of the site, including Enderby House, to Barrett Developments for housing, which commenced in 2014.

Enderby House was Grade II Listed in 1973, due to it close links with local industry and technology development.

Our works were concerned with extensive masonry stabilisation, as decades of neglect had taken their toll on the 170-year-old structure. A comprehensive scheme was developed between Helifix and ourselves, which saw 6mm diameter Helifix HeliBars being installed to form load-bearing masonry beams and to stabilise cracked brickwork. This was followed by the installation of Helifix 8mm diameter CemTies to pin the window head/arches to the newly formed beams.

The project was completed within a challenging contract programme, where numerous other trades were present.

Enderby House will now re-open as a public house run by Young & Co. Brewery PLC.

The Hoover Building


Hoover Building Structural Renovations

Structural Renovations Limited completed a 12 month concrete repair and specialist coating project at the iconic Hoover Building in Perivale, West London.

The building was constructed as a factory for the Hoover Company in 1933 to the design of Wallis, Gilbert & Partners, who were inspired by the Mayan and Aztec fashion displayed at the 1925 Paris Exhibition and remained operational until its closure in the 1982.

During the Second World War the factory was used to manufacture parts for various aircraft and the building was camouflaged with netting to help avoid being attacked.

Being of significant architectural importance the building was Grade II* listed in October 1980 and in 1989 Tesco purchased the site and set about converting the rear into a large supermarket, including sympathetic recreations of various original building motifs around its entrance and car park.

Structural Renovations were employed to carry out a condition survey of the concrete to the original structure and from the results of the survey we developed a specification for its repair and protection, based on the use Sika products.

Structural Renovations were instructed to carry out the repair and restoration works and following an initial clean we were able to identify all spalling and defective concrete. Where required the concrete was repaired using a polymer modified repair system, combined with the installation of a vapour phase inhibitor, to control any ongoing corrosion to the embedded reinforcement.

Previously painted areas received a multi-coat elastomeric system and unpainted elements of the building had a clear anti-carbonation coating applied.

Finally, all existing sealants at the junction between window frames and painted concrete were raked out, prepared by priming and reinstated with a one part low modulus sealant.

During our external works the internal areas of the original building were converted into 66 luxury apartments by IDM Properties.

We are proud to have been involved in prolonging the life of this prestigious example of Art Deco architecture and it demonstrates the capabilities of our Company.

The Observer Building, Hastings


Observer Building Concrete Repairs

Structural Renovations were awarded the contract to complete extensive structural repairs and apply protective coatings to all reinforced concrete within the landmark structure, known as The Observer Building, in Hastings town centre.

The building was originally constructed for the publishers and printers, F. J. Parsons, in 1924 and was designed by the Hastings architect, Henry Ward.

The building was subsequently used by The Observer Newspaper as both a printworks and its administrative centre, until vacating in 1985. The building has remained empty and neglected in the years between, which has allowed significant deterioration to be caused to the entire building fabric and in particular the reinforced concrete structure.

A number of surveys have been conducted over the years, when various parties showed an interest in taking on the building and each survey shows the increasing damage caused, in the main, by water ingress.

The building was finally purchased by White Rock Neighbourhood Ventures in late 2018, who, together with the assistance of various funders, intend to bring this impressive building back to life and utilise the enormous space available.

Our works have involved surveying all concrete surfaces to identify the full extent of defective concrete, before its removal back to a sound substrate. All exposed reinforcement is carefully prepared prior to be in treated with a proprietary primer. The prepared areas are reinstated using a cementitious, polymer modified repair mortar.

Due to the sheer size of the structure internally (in excess of 5,000m²), it was decided that the protective anti-carbonation coatings would be applied by airless spray equipment, which was purchased specifically for this project and has enabled the process to be sped up considerably.

During the works approximately 15 tonnes of repair mortar will be used and over 2,000 litres of anti-carbonation coatings.

It is testament to the original design and construction of this building, which was left to decay for so long that its repair was viable, and demolition was not necessary.

The external elevations of the building are hoped to be completed as part of a separate phase, which will be carried out in the near future.

Westlands Primary School, Sittingbourne


Structural Renovations Helifix

Structural Renovations secured the works to complete concrete repair and masonry stabilisation to Westlands Primary School in Kent, working as a specialist sub-contractor to Kier Construction.

Westlands Primary School was constructed in the 1960’s and is a typical example of many schools built during the period with brick facades, reinforced concrete features such as window cills, window surrounds, columns and flat roofs with overhangs.

The window cills, lintels and surrounds are constructed from reconstituted stone or ‘engineered stone,’ using natural stone aggregates, such as portland, mixed with a cementitious binder, that is intended to resemble natural quarried stone. A recurring issue with this type of construction is that the embedded mild steel reinforcement which is used to provide tensile strength is compromised by both low cover and the relative high porosity of the reconstituted stone. This leads to expansive corrosion of the reinforcement (due to the presence of moisture and oxygen) and causes the ‘stone’ to crack and spall. Entire sections can be damaged by this process and repair is generally the most cost effective and practical method of treatment.

The treatment in this instance was to mechanically remove all loose and defective ‘stone’ together with any reinforcement that had lost significant section. New stainless steel reinforcement was fixed in position using a two part polyester resin. A temporary timber shuttter was formed to the profile of the area to be reinstated, which included drip, upstands and falls. The prepared broken back surface and reinforcement was coated with Sika MonoTop 610 and reinstated with Sika MonoTop 615 back to the original surface profile.

The brickwork in places at Westlands Primary School had diagonal, stepped cracking which required stabilisation. These were reinforced using Helifix Helibars set in Helifix Helibond Grout, a non-shrink cementitious grout, within the bed joints at regular centres along the length of the crack. Once installed the reinforced areas were repointed to match the existing pointing.

The works are to be completed over a number of phases to suit both the major refurbishment scheme by the Principal Contractor as well as the school term times and operating hours.

Royal Hospital Chelsea


Royal Hospital Chelsea

Grade I listed and designed by Sir Christopher Wren, ‘The Royal Hospital’ was founded by King Charles II in 1682 as a retirement and nursing home for soldiers of the British Army.

The hospital is situated close to the River Thames, in the the Royal Borough of Kensington and Chelsea on a 66 acre site. The residents of the hospital are known as ‘Chelsea Pensioners.’

Structural Renovations were employed by Wates Construction to stabilise the chimney breasts within the building, reform feature brickwork dressings around windows and repairs to stonework within a number of the rooms.

The chimney breasts had the timber panelling removed exposing the cracked brickwork beneath. Bed joints at regular centres were ground out, being careful not to damage the 300 year old hand-made bricks. Stainless steel helical bars, set in non-shrink cementitious grout were installed into the pre-soaked slots. The slots were then repointed using a lime mortar.

The deep red brickwork dressings around some window openings had, over time cracked and spalled due to expansive corrosion of metal inclusions and frost damage following moisture ingress. The defective brickwork was removed using only hand tools to avoid further damage.

Stainless steel pins were drilled in to sound substrate and set in a two part polyester. Usually a specially colour matched, modified mortar, the repaired areas were reinstated and whilst still not fully cured the brickwork was carved to the required profiles to include ‘dummy’ perp and bed joints, which were subsequently pointed with another colour-matched mortar.

Stone work repairs were completed using stainless steel pins for support and a colour-matched, modified mortar.

This project was secured with Wates following successful completion of masonry repairs to Somerset House another one of London’s Grade I listed buildings.