Whitley Bay’s Dome: strong again

When it came to renovating the one of the country’s earliest reinforced concrete domes, English Heritage and North Tyneside Council, working with project conservation architects Spence & Dower of Morpeth, needed a proven and durable method of refurbishment.

The Spanish City was originally Whitley Bay’s famous permanent seaside fairground until its partial demolition in the late 1990’s. Now the Grade II listed Spanish City Dome has become the centrepiece of a multimillion pound regeneration of the seafront complex, which will include hotel and leisure developments.

Featured in Dire Straits’ famous song Tunnel of Love and enjoyed by thousands of holiday goers over its 99-year history, the Dome’s careful restoration was of paramount importance. With its seafront placement, it also meant that the work had to be able to stand up to tough coastal climates.

Following careful examination of the concrete rotunda, it was found the structure was sound, testimony to the engineering and the durability of concrete, but a number of repairs were required to ensure the building’s future. This included repairs to the building’s ground breaking Hennebique ferro-concrete construction.

It was proven that a range of products would be able to repair and protect the concrete dome and provide future protection for the building’s steel reinforcement.

Monotop 610, the chosen repair product is a one-component, cementitious, polymer modified mortar containing silica fume and corrosion inhibitors. It provides a proven method of preventing continued corrosion of steel reinforcement in concrete as well a bonding bridge for the company’s Monotop 615 cement based polymer modified high build repair and re-profiling mortar.

This was applied to the exterior of the structure which, due to its dome shape. After preparing the surface, two coats of Monotop 610 were applied before being followed by a layer of Monotop 615. This was completed as a ‘wet on wet’ application in subsequent layers until completion. Together this provided a seal over the dome, preventing any corrosion or degrading of both the concrete and steel reinforcing.

The dome’s steel reinforcements were protected by Sika’s Ferrogard 903. Surface applied, it works by seeping through the pores of the concrete and defending them against corrosion – retaining its strength for many years, it is a simple and economic means of keeping the structure in good condition.

Further weather resistance was provided by the outer layers of Elastofill which is an elastic filler coat that seals the pores of concrete and prevents its carbonation, fur-ther preventing the corrosion of the steel reinforcement beneath.

Elastic coating is water based pigmented elastomeric protective concrete repair product. As a result of detailed analysis of all the existing layers of paint on the dome, by a specialist paint consultant, was deemed to be the closest match to the original 1910 colour and was added as the final finishing coat to the structure. This hard wearing top layer also prevents carbonation and is resistant to salts - perfect for a seaside attraction.

The twin elements of Elastofill and Elastic provide the final weather resistance to the structure – crucial on the unpredictable North East coast. Designed to stand up to any climate and resistant to freezing and thawing due to their elasticity, they will ensure that the dome is protected from the weather all year round.

Designed in 1909 by architects Cackett & Burns-Dick of Newcastle, the Dome is an early example of the Hennebique patented system of reinforced concrete construction and when opened in May 1910, it was the largest dome in the UK after St Paul's Cathedral. Now restored and protected bymarket leading know how, Spanish City will be keeping Whitley Bay’s tourists happy for at least another century.