Stone Clips

* The two optional fixing points on the left and right hand side of the clip sometimes have to be fixed at a slight upward angle.

If pins finish in this position when installing and adjusting, you must fix to substrate with 2 fixings to maintain position of clip and load distribution.

If panels are resting on connecting shafts of the StoneClips used, they are in effect, only carrying the weight of the panel directly above and this is divided by the two pins. This can vary from:

Type	Density	600 x 300mm	600 x 600mm	400 x 800mm
20mm sandstone	2.350	4kgs per pin	-	-
30mm marble	2.500	6.5kgs per pin	13.0kgs per pin	12kgs per pin
40mm granite	2.700	9.7kgs per pin	19.45kgs per pin	17.3kgs per pin
50mm sandstone	2.350	10.6kgs per pin	21.6kgs per pin	18.8kgs per pin

These are shear loads and are for voids up to 12mm from substrate. Where voids are widened up to 30mm it is advised to open gaps from 1mm up to 3mm. These can be left open for circulation and movement of air around panels or can be silicone jointed (normally to a depth of 5mm). It is recommended that every 3000mm of floor height of next lift that you have an 8mm joint between levels. This allows for all movement that may occur on face of external or floors internally.

To achieve the above mentioned joint spacings between panels, it is best practice to install where panels are (600 x 400 x 20-40mm) out 3 fixing points to each StoneClip - that is one pin at 12 o'clock and one each at 3 o'clock and 9 o'clock. To achieve the gap required, you should use a router and indent the top of the panel in the back portion (facing substrate) with a 6mm deep indent.

You then lay in the bottom indent a piece of high quality nylon (the diameter of the joint you want to achieve), then rest the shaft of the StoneClip on this and fix into plumb position. 1 - 5mm spacers that have been cut with a sharp knife are ideal of this use.

The kerfs that are cut in the panels are always out in the middle of the panel edge (eg, 15mm in, in case of 30mm thick panels). This hangs all panel in neutral pressure on the fixings. Make all cuts from the front face, except in the case of rock or split faced stone. this ensure all front faces are aligned right and only required the panel to be plumbed in position as installing. Aim to use a diamond blade that cuts a kerf that is around 2mm wide. This allows room to install front disc of StoneClip with only a 0.3mm gap for movement in the kerf.

This is important to have to counter twists that may, and probably will occur in panels from 30mm down. The silicone that you inject into the top cut on the panels firms up after 12 hours. when working with the movement of the panel, it can been seen that by doing this, it fixes the top turning point of the panel and allows the bottom to move in the kerf.

When you are using the StoneClips as intermediates, having the bottom course ready to take the course stone above, you will notice that there is very slight movement there until the next panel above is fitted into place. This is not there when you use the top and bottom clips (see drawing on right).

DISCLAIMER: The StoneClips must be installed along the lines of the Engineers Detail, including the installation of angle restraints at each lift level and the use of the right fixing restraints.