14 | GROUTING TECHNIQUE
1/2/3. Cut the end of the piping bag provided with the mortar to create a hole of approximately 1.5-2 cm.
4. DO NOT APPLY MORE MORTAR THAN IS REQUIRED ON A GRADUAL BASIS. The mortar should be ductile and friable, not too wet and not too dry.
5. THE PIPING BAG FILLED WITH THE MIX, should be supported in one hand while the other twists the upper section of the bag. This creates a pressure that pushes the material out of the nozzle.
6. THE NOZZLE MUST BE INSERTED DEEP INTO THE JOINT tilting sideways by 45° with respect to the grout direction. When injecting the material move at a speed that makes it possible to deposit the required quantity of mortar in the joint.
NEVER WORK WITH MORTAR WHICH IS STILL SOFT. Do not use WET spatulas, brushes or sponges.
Smoothing joints with brushes or wet sponges as typically occurs with stonemasons in some areas is to be avoided. In practice this operation deposits a thin film of lime on the stone in the form of a whitish film, which is invisible when wet but is not aesthetically appealing when dry.
7/8. CARRY OUT MANUAL CONSISTENCY TESTS to verify workability times. When surface water is no longer present (dry fingers) the mix can be worked and manipulated.
9. PRESS THE MIX INTO THE JOINT, removing any excess with a wooden stick and working it according to need and preference. Spatulas and trowels can be used for special mortar effects to recreate aged grouting or a scaling effect on walls (see section 15).
10. CLEAN THE AREA with a completely dry natural bristle or soft brush, observing grout setting times in relation to the finishing technique implemented (never clean immediately after working the mortar, always wait till dry).
Note! The colour of the mortar is sensitive to the following factors: type of manipulation, temperature, manipulation at different drying stages, rain or ice in the subsequent 48 hours. Changes in colour with the formation of marks or stains may transpire (see photo).
Avoid cleaning runs that are still wet on the stone, only remove them after initial shrinkage has occurred. Remove hardened lumps with a wooden stick then clean the remaining mark with a damp sponge, avoiding wiping where not required.