There are many ways of laying sandstone, here are some: you can put it under the joining in a finger as thick as it is; you can saw clear shapes with smooth edges and put with 2-3 mm seams; you can do exactly the same but also chamfer. Consider the last way.
Sandstone as it is
Sandstone cutting without chamfers
To complete the work, we need:
- grinder with a circle on a stone,
- cardboard for cutting templates,
- construction pencil,
- sharp scissors,
- mixer for mixing glue,
- Master OK.
Before laying a wild stone, it must be thoroughly washed, since it has a rather thick layer of its own dust. If this is not done, then there is a high probability that it will fall off very soon. A hose with a spray at the end is well suited for washing, and in the absence of one – a hard brush with a short nap and a bucket of water. The stone is carefully sprayed with water pressure and, if necessary, cleaned with a brush until dust and loose particles disappear completely. In the case of laying stone on glue for tiles, it must also be dried, which is due to technology.
Drying the stone
We pull the threads
Due to the fact that sandstone does not have a clear, uniform thickness and its surface is quite rough, it is most convenient to lay it along threads (or fishing lines), maintaining the same gap of 2-3 mm. To do this, you need to pull two parallel threads along the level (or with a slope so that the water flows down), and already along them pull the thread-slider, which should move freely over the entire area.
Sawing a stone
Next, we cut a few stones and lay them out on dry so that they fit together. It looks most attractive when the corners of different stones coincide with each other. It is most convenient to first select and cut out a cardboard template, redraw it onto a stone, and then cut it. After that, a chamfer is removed with a width of 3-5 mm – at the discretion of the master. A small grinder or water-cooled tile grinder is used as a sandstone cutting tool. It should be noted that this job is very dusty, so a water-cooled machine looks preferable.
Lay out on dry
We continue to pick up dry
Sandstone is placed on tile adhesive, cement mortar 1: 3, or a mixture of both. The mixture is made at the rate of 1 part of cement mortar (1: 3) plus 1 part of glue. The density of the solution is made such that it does not float in the bucket, but stands still, that is, it is plastic and therefore maintains the position set by the trowel. The optimal layer is 1 – 2 cm. The stone is pre-coated with a thin layer of glue (rubbing in the glue), and then put on the main layer, beating with a rubber hammer.
For wedging stones, it is better to use large wedges for tiles or, in extreme cases, matches. There must be glue in all seams, because if water gets into the seam and freezes, then the stone can rebound. Excess glue is carefully removed with a small spatula or stick, so as not to stain the edges of the sandstone in any case, because then the whole view will be lost. The surface must be pre-impregnated with a deep penetration primer such as Ceresit CT17 to improve adhesion.
Alone, the speed of sandstone laying is low – about 0.5 m2 per day, as it takes a lot of time to fit templates and cut stones. It turns out that the master first needs to manually make the material for the masonry, and then put it down as well, but there is no other way to do it. Work can be accelerated by using large stones as often as possible.
When working with a wild stone on the facade, remember that laying can be done at temperatures above +5 degrees, and you also need to remember about rainy weather and plan work based on your climatic zone.