In everyday life, it is often necessary to fix something on a concrete wall. And many people perceive this as a serious problem, which is quite natural, since even self-tapping screws on concrete without drilling a fixing hole do not pierce a monolithic surface.
However, the selection and installation of specialized fasteners, in fact, is not as complicated as it might seem at first glance. Concrete is one of the most durable artificial building materials today, which explains the complexity of the implementation of fasteners.
Phased installation of fasteners without the necessary knowledge and skill can cause a lot of difficulties and problems that can not be ignored. There are a lot of different items that are specially adapted for working with concrete, and each sample requires a special approach.
The most popular means for working with concrete surfaces are self-tapping screws for concrete, which are specially designed for installation by hand. They allow you to mount on the concrete almost any hinged structure without any special difficulties.
At the same time, the price of this product is quite democratic, compared with anchor analogues, which will cost you much more expensive.
In this article, you will be given detailed instructions on how to use the screw on concrete. With our help, you will be able to choose the name for your circumstances and carry out the correct installation of the purchased products.
There are several types of screws, which differ from each other type of attachment, material and structure. The choice of a particular name depends on the situation and external influences that have a direct impact on the fastener. Consider the most common types of screws and their scope.
This is the most common type of fasteners in the construction market - they are produced in the form of self-tapping screws with two types of thread and plastic dowels. The presence of the dowel is due to the fact that the hole drilled by the drill in the concrete is not capable of providing tight fixation, without which the fixing would not be reliable. The plastic casing performs the function of a seal that smoothes this circumstance as much as possible.
If you choose self-tapping screws for aerated concrete, fixings with dowels are the best option. Given the low density of the foam material, self-tapping screws on aerated concrete without a compactor will not be able to provide an adequate safety factor.
Plastic casing increases the contact area of the screw with the wall, which is especially important in the case of concrete of low density.
There are two types of screws with dowels, which differ from each other in the structure of the thread.
- “Herringbone”. Herringbone profile is a non-interlocking thread, which is fixed in the hole according to the principle of nailing in concrete. Such a screw after fixing can not be removed by twisting, which greatly complicates the dismantling. However, they also do not need to twist - just a few strong blows, which in some cases can significantly simplify the installation process;
- Universal profile. This product looks like an ordinary screw and is mounted accordingly. The screw is simply screwed into the dowel, and when dismounted, it is removed by twisting. This type of attachment is somewhat inferior in reliability to the previous name.
Note! The design and shape of the dowel is determined by the manufacturer and, as such, the difference in carrying capacity between the various names is insignificant, provided the quality of the material used.
The sizes of self-tapping screws on concrete make from 3 - 6 mm on diameter and from 12 to 220 mm on product length. Herringbone screws may be more massive in diameter, but somewhat limited in length.
Installation of self-tapping screws with dowels is carried out in pre-drilled holes, which must match the diameter of the plastic casing. The dowel must fit tightly in the hole and not hang out. After which the fastener itself is driven into it.
Note! The drilled hole should be deeper than the length of the screw with a complete set to compensate for the expansion of the shell after fixing fasteners. A few millimeters will be enough.
Screws without dowel
Шурупы без пластикового уплотнителя носят название “нагели” – их отличает переменная резьба, которая позволяет саморезу укрепиться в бетоне. Среди непрофессионалов, бытует мнение, что саморезы в бетон без дюбеля вкручиваются без сверления вспомогательного отверстия – оно является ошибочным. Таким образом, вкрутить шуруп можно лишь в газобетон, что не является целесообразным, как сказано выше (читайте также статью «Анкерные болты по бетону – разновидности и принцип устройства»).
Before twisting the screw into concrete without dowel, it is necessary to drill a hole with a special drill with a diameter of 6 mm (the diameter of the dowels is 7.5 mm). Only after that the screw is screwed into the hole by means of a screwdriver - a variable notch will expand the cavity, and the upper thread will fix the screw.
This type of fastening refers to stationary solutions - before screwing the screw into concrete, it is necessary to accurately determine its location, since after fixation, it will no longer be possible to unscrew the fastener.
For the most part, self-tapping screws for concrete are made of carbon steel, which is covered with a protective layer to protect against corrosion. The exception is made of stainless steel screws, but their price is much higher than ordinary counterparts.
There are several options for protective coatings, among which the following should be highlighted:
- Galvanized. The zinc layer has a characteristic metallic silver luster - it is the most reliable anti-corrosion coating today. These products can be used both indoors and outdoors;
- Copperplate. The yellow screws are coated with copper or brass - their use is limited to internal work;
- Oxidized. Black screws are blackened, as a result, on their surface an oxide film is formed, which prevents the formation of rust. They can only be used in conditions with normal humidity.
Self-tapping screws for concrete will help you greatly facilitate the installation of such things as a chandelier, kitchen set, etc. Larger difficulties with concrete structures will help you to solve diamond drilling of holes in concrete and cutting reinforced concrete with diamond circles (find out here how to install concrete on the wall).
Visual information on this topic can be obtained by viewing the video in this article.