Barbecue Table

The barbecue table carries the hardest combination of conditions in stone work: both high heat and outdoor exposure. The recessed barbecue section at the centre heats the stone at a single point while its surroundings stay cold. That temperature difference creates stress within the stone, and where it is not detailed correctly a crack can appear on the work's very first use.

The solution is a two-part arrangement. The firebox does not sit directly on the stone; a thermal insulation gap and insulating material are provided between the firebox and the stone, so the stone is in contact with indirect heat rather than flame. The edge of the firebox opening also matters: because a sharp internal corner is the point at which stone will begin to crack, the corners of the opening are radiused. This cut is made by CNC in the workshop, not on site.

Outdoor exposure is the second condition. Water entering the stone's pores through the winter expands as it freezes and cracks the stone from within; this is called frost damage. To prevent it, a stone of low porosity is chosen for outdoor work and the surface is always saturated with an impregnator. A very slight fall is also given to the table top so that rainwater runs off rather than collecting on the surface. The barbecue table in this catalogue was made in a grey stone; dark grey and smoked tones carry both soot marks and limescale better outdoors than light colours do.

The leg and support system is also built for outdoor use. If the table is not fixed to the ground, the legs need to be stainless or galvanised; painted steel rusts by the end of a season, and the rust runs onto the stone surface leaving a permanent mark. In the work shown here the table stands on a timber deck and the leg bases were kept wide, so the weight does not bear on the timber at a single point.

On the use side there is one warning: ash and fat from the barbecue section can leave marks when they contact the stone surface while hot. Waiting for the surface to cool before wiping, and renewing the impregnation at the start of each season, keeps the table looking as it did on the first day.