A commission to construct an underground cavern structure around a new build swimming pool and sauna saw our Managing Director and gunite crew travel to Southern Ireland for something very out of the ordinary. A ninth century Celtic keep requiring a complete rebuild without ‘Disneyfying’ was the basic brief, but no formal specification or design in place for the underground constructions.

Our remit was to create a natural rock formation to replicate a cavern in the underground pool area.

Sprayed concrete was the preferred method to create an organic natural space in an otherwise utilitarian rectangular basement, to include all walls and ceiling, and presented several construction issue for the type of materials to be utilised in this construction.

The chlorine rich environment of an enclosed swimming pool required a heavy reliance on stainless steel mesh and stainless dowel bars in preference to standard mild steel reinforcement to mitigate the potential problems of chloride attack.

A lack of access to quality construction materials or high specification ready mix concrete meant that Dry Spray Gunite materials (C50 fast set) were shipped in from the UK, together with stainless steel mesh, stainless straight bar and high specification resin anchor grout.

Without a formal specification or design, every part of this construction was overbuilt and done to the highest possible construction standard that we could achieve (actual costs were not really an issue for our client, just the highest standard of work and structural integrity / longevity).

Following successful completion of this phase of works, we were asked back to site later in the year to construct an additional sprayed concrete natural rock formation waterfall to fill the moat around the castle!