Traditionally used for basement construction, a waterproof concrete system from Sika has been chosen for a highly technical and unusual application - the construction of a rectangular concrete hull for a luxury houseboat. The Sika waterproofing solution ensures the boat would not only be watertight and offer long term performance but also help create a floating foundation that would stand the test of time.

Built by H & J Construction at Hythe Shipyard for Jeremy Swadling, the houseboat required a concrete hull as it would benefit from good resistance to impact, fatigue and cracks propagation resulting in less long term maintenance. With a heritage that goes back to before WWI, the use of concrete in boatbuilding is not new and as it requires no expensive moulds such as in glass-reinforced plastic boat construction, it can produce an inherently strong and rigid hull at a relatively lower cost.

 

To meet the requirements, the specification included 64m3 of Sika Watertight Concrete to deliver outstanding levels of watertightness to the heavily reinforced concrete box frame of the boat. Extensive reinforcement was required to prevent any flex in the base of the hull should the boat be subjected to any freak waves at its mooring.

Measuring 25 metres long by 7 metres wide by 3 metres deep, the massive concrete hull features a ribbed spine design along its length with 4 metre long strengthening piers on both sides.

 

Typically specified for below ground and basement construction, Sika Watertight Concrete is a high quality solution that prevents water from migrating through the concrete. State-of-the-art Sika admixtures work within the concrete, firstly to reduce the water/cement ratio, thus increasing the density of the mix and minimising the size, volume and continuity of the concrete's pores, and secondly, fill the remaining pores.

Luke Eastman, H & J Construction commented: “The Sika Watertight Concrete system was ideal for this unusual application as it was vital that the concrete created a watertight hull with a crack free and permanent seal.”

 

With the luxury houseboat fitted out and now moored at Bembridge in the Isle of Wight, the successful application of Sika’s watertight solution has played a crucial part in the longevity of this vessel and ensured it remains waterproof for the long term.