Correct! Not all drilling is the same. Of course, everyone will still manage to drill a hole in a wall. But the result will be very different. Kitchen cabinets have already fallen from the wall, freshly hung pictures have broken, and half walls had fallen over when an antenna cable breached because drilling is not just drilling. This article aims to help teach you how to drill properly in stone and concrete and to avoid making fundamental mistakes. Because to drill concrete properly, a lot has to be considered.
THE CHOICE OF THE DRILL BIT
As with painting, it is essential to know the subsurface when drilling properly. This is the only way to choose the right drill – and only the right drill ultimately leads to success. The subsurface alone decides which drill is right or wrong. In the case of plastered walls and ceilings, however, it is usually complicated to see which substrate is present.
But before trying, at least one property can be determined with certainty. Simply knocking on it will determine whether the wall or ceiling is a lightweight construction made of plasterboard or solid construction. If there is a massive construction, the further condition usually remains a secret until the second hole.
The existing drilling dust from the first hole provides further information on the composition:
- Brick wall – red drilling dust
- Limestone wall – white drilling dust
- Concrete – grey drilling dust
- The right drill for natural stone and masonry is always a hard metal tipped stone drill. For concrete, as is often found on the ceiling and floor, a concrete drill is always required. Without it, it is almost impossible to drill concrete properly.
IMPACT DRILL OR HAMMER DRILL
A hammer drill is usually sufficient for all holes in all materials – except for concrete drilling. Nevertheless, concrete drills up to 12 mm thick are also sold for impact drills. It may make holes in concrete, but it’s not fun. In addition to strength and effort, it also costs a lot of material, because the drills do not withstand this load for very long.
This can be remedied by a hammer drill – the tool for working concrete. With powerful blows forwards, the hammer drill works its way effortlessly through the concrete. When drilling with a rotary hammer, you should therefore not drill with pressure, because the hammer mechanism of the rotary hammer takes care of that.
THE SIZE OF THE DRILL
To do it correctly, the drill holes must always be drilled to match the dowel. These can and must be several millimetres longer than the actual dowel, but if the diameter of the hole is too large, the dowel has no hold. On the other hand, if the hole is too small, there is no place for the anchor. Correct drilling, therefore, depends on the size.
Piercing electrical lines in the wall can be life-threatening! It is also not particularly pleasant when water pipes or even the heating hoses of the underfloor heating are drilled. If you are not sure how the lines run, you can check it with a measuring device before drilling. There are measuring devices that can be used to detect live lines, but also water lines.
Tip: Power lines usually run vertically or horizontally and never diagonally away from the switch, socket or junction box. But be careful: control is better here!
CORRECT DRILLING IN CONCRETE AND STONE
Drilling in stone and masonry
In stone and masonry, drilling the first millimetres is correct without using a hammer or hammer, even if it takes a little more effort. If these functions were to be switched on immediately, the wall or stone could burst away directly at the drilling site, and the small hole inadvertently turned into a crater. Besides, only clinker, solid brick and solid stone are hammer-drilled, so that the hammering function is only activated when it is known that these are actually present.
When drilling concrete, many do-it-yourselfers slip right at the start of drilling. In order to drill the first millimetres of the hole correctly, a little trick helps enormously: An old drill, an old large screw or the like is placed on the future drill hole. Then, with a few strong blows of the hammer, an initial, minimal depression is created. In this way, the actual drill can then sit more firmly at the point to be drilled, and the drill prevents it from slipping or turning away. Then it is easier to drill into the concrete.
Drilling the wall breakthrough
If a wall breakthrough is required, then particularly careful drilling should be carried out. Especially when impact or hammer functions are used, a not inconsiderable part of the wall there can be knocked away when the breakthrough on the other side occurs. It is advisable to drill from both sides if possible. This prevents the surface from chipping off when the wall breaks through.
The final step in properly drilling stone and concrete is pulling out the bit while twisting it. This not only prevents unwanted from getting stuck in concrete or stone but also reduces the risk that the drill hole will break out at the entrance due to tilting. In addition, the rotary motion of the drill continues to propel the drilling material out of the hole.
Finally, the drilling dust is removed from the drill hole by blowing or sucking it out so that the dowel and screw find the necessary space.
Correct drilling means that too large holes and chipped parts of the wall are a thing of the past. If you take these tips to heart when you drill your next concrete drill, you can also enjoy precise drill holes!