PREFABRICATION
The mosaic is pre-fabricated at the workshop, and can be compared to a giant jigsaw puzzle with pieces of very varied shape. Installing a mosaic is similar to laying large-scale stone slabs, except that the extra depth of the mosaic and the different shapes make the job more challenging. We provide a site plan which shows the shape of each section; these are numbered to enable the jigsaw puzzle to be put together with ease.

DIMENSIONS
Slabs average 750x750mm. Depth: 75mm. Maximum weight: 150 kg.
All slabs can be conveniently handled and laid by two men.

SITE PREPARATION
A base should be provided for the mosaic, with layers of stone or concrete suitable for its intended usage. Detailed recommendations are available on request. A border of stone or sets should be planned, to protect the edges.

THE CASTING PROCESS
Fabricating the mosaic can be described as a “reverse” technique; (like an “upside-down” cake). Each section has an individually-constructed mould into which the pebbles are placed with their top-side down, & packed vertically within the mould. Like icebergs, there is a lot more of each pebble embedded in the slab than is visible on the surface. This technique ensures that the finished surface feels comfortably flat underfoot.

The first stage of casting uses a non-shrink cementitious grout, which penetrates the tiny gaps between the pebbles and ensures a very hard final surface. The slab is completed with concrete (3:2:1), tamped and vibrated. The slabs are cured under polythene wraps for 4 weeks to attain maximum strength.

INSTALLATION
The mosaic is delivered to site packed vertically on palettes. Maggy Howarth or another craftsman from Cobblestone Designs undertakes to supervise the installation continuously.

The mosaic slabs are bedded on mortar on to a previously prepared site. Since it is more economical to use local labour already on site to lay the slabs we usually estimate for supervision only.Then we complete the job personally by grouting the joints between the slabs of mosaic, using the same non-shrink grout which was used in the casting process.Altogether, the time taken for the installation varies from 1 day (for a 3-metre mosaic) to 5 days (6 -metre mosaic)