For the construction of a new single span bridge in the small Welsh village of Cwmtwrch the concrete deck had to be sufficiently robust to resist vehicular loading, de-icing salts and possess long term durability. Sika’s new Sikalastic fast-curing deck waterproofing system was specified to ensure the longevity and integrity of the bridge.


In a bid to maintain the links between the villages of Cwmtwrch and Pen Rhiwfawr, Neath Port Talbot and Powys Councils decided to demolish the current Crown Bridge which was suffering from ageing and concrete degradation and was structurally unsound for vehicles over three tonnes. The replacement would be a new 20 metre steel beamed bridge with a reinforced concrete deck which was protected with the Sikalastic 841 ST waterproofing membrane.


Following the construction of the bridge and concrete deck, the main contractor Ian Davies Plant Limited was appointed to complete the waterproofing application which involved levelling out the surface with Sika concrete primer, utilising its fast curing abilities and low viscosity to ensure deep penetration of the concrete substrate and rapid overcoating with the waterproofing membrane.


The contractor then installed the Sikalastic 841 ST waterproofing membrane, a two part, elastic, 100% solids, very fast curing pure polyurea spray applied membrane. With excellent crack bridging properties and a high weather tolerance from -30°C to +100°C, the Sikalastic 841 ST allows a smooth installation process during an extremely cold winter or summer period.


“The Sikalastic waterproofing membrane met our specification requirements for the waterproofing and provided a very cost affective material,” commented Paul Ransome, Senior Assistant Engineer, Port Talbot Borough Council.


Once fully cured, the membrane was covered with a hot rolled asphalt – comprising fast setting Sika concrete primer broadcast with Sikalastic-827 LT hot pelt pellets. Fully bonded to the substrate and the asphalt, it provided excellent adhesion and shear strength.


With BBA-HAPAS accreditation covering manufacture, specification and performance the Sikalastic system gives highway designers peace of mind to specify this fast-curing bridge deck system at projects across the UK.


With the bridge now open and the link between the villages reinstated for all vehicles, Sika’s innovative products proved once again why they are a favourite for specifiers and operatives the world over.