Is it possible to install an anchor bolt in wood? Wooden fasteners: main structural elements and methods of their installation (85 photos)

Are anchors suitable for wood? How to securely attach a chandelier, hanging bed or other massive thing to a wooden beam with them? What other means can be used when merging wood structures? Let's find out!

Types of anchors

The word “anchor” is of Germanic origin, its main meaning is “anchor”. Anchor fasteners are used when installing various products on a base made of wood or concrete.

There are several types of “anchors”:

• spacer;
• persistent;
• adhesive;
• Bolt Molly.

The expansion anchor is held in the workpiece by frictional force. To maximize it, the rod installed in the hole is expanded with a plastic dowel or wedge stop with a thread inside.

The fixation of the thrust bolt is ensured by the ribbed or expanding part of it embedded in the base. This is exactly how the fastenings used when installing heavy production plants on a concrete foundation are designed.

Adhesive “anchors,” as the name implies, adhere to the surface due to the sticky composition entering the void between the walls of the hole and the ribbed rod. Most often, the role of an adhesive mixture is performed by a polymer resin with a hardener.

The Molly bolt is used when hanging products on low-strength partitions made of gypsum fiber board, chipboard, gypsum plasterboard and hollow brick. In the process of tightening, Molly pushes the outer shell apart. As a result, a stop appears that is in extensive contact with the base.

Note: craftsmen often call adhesive anchors “chemical”.

Now let's figure out what type of anchor bolts are suitable for in various ways fastening to wooden structures:

• The Molly Bolt can only be used on surfaces that have large voids inside. That is, this method is only suitable for hanging relatively light objects on partitions made of boards, chipboard and lining;
• thrust anchors are used only in the process of creating a massive foundation. In the case of wood, this is the growth stage of the tree trunk, so such fastenings will not suit us;
• glue “anchors” can be used when working with wood, but this is not always advisable due to the high price of this product.

Important: large changes in humidity can lead to loss of adhesion between the body of the chemical anchor made of hardened resin and the walls of the hole, which will cause the fastening to become unusable.

Based on the above facts, we can conclude that the anchor fasteners for wood must be spacer. However, another important factor should be taken into account here: depending on where the force is directed, the strength of the wood may vary:

1. If the force vector runs parallel to the fibers, the material is more tensile;
2. If the force vector is perpendicular to the fibers, the destructive force will be several times less.

Speaking in simple language, wood is more likely to split if wedged between the grain. At the same time, typical expansion fasteners produce a radial expansion force that can pose a safety hazard. wooden base.

To reduce the pushing force, craftsmen resort to a simple maneuver:

• The wood itself is used as a dowel (propping element);
• The hole for the rod is made only slightly smaller than the diameter of the ridges of its thread.

The design that matches this description is probably familiar to you - it’s... an ordinary screw!

Wood fasteners

Fasteners suitable for connecting wooden structures have several features:

Manufacturing options

The most common types of wood anchors are:

• hex head bolt. It is used for attaching various brackets, plates and other flat and large structures with lugs to wooden bases;
• a stud with a nut, which is screwed in with a wrench (open-end or adjustable);
• a hook that acts as a strong suspension and is suitable for mounting chandeliers, hanging shelves, lanterns, and so on;
• the ring performs the same functions as the hook. Its main distinctive feature is that the ring prevents the suspended product from jumping off it when moving in space (for example, the ring can be used to create a children's swing). To attach a suspended structure to it, threaded or spring carabiners are used.

Installation

How to screw a wood anchor with your own hands so that the fastening is as reliable as possible and the base does not split?

The procedure in this case is not at all different from the technique of screwing in a large diameter screw:

• drill a hole at the mounting point. Its diameter must correspond to the diameter of the fastener along the thread recesses. So, a channel for a 10 mm rod must be made with an 8 mm drill;
• apply a certain amount of liquid or solid soap to the threads for lubrication;
• screw the rod in to its full depth.

Important! The depth of the hole should correspond to the length of the rod. If the depth is less, then the bursting force on the wood will increase sharply, which can lead to the appearance of cracks (if not immediately, then as the structure is used).

Other types of fasteners

In addition to the "anchors", wooden structures can be connected using conventional bolts, studs, perforated plates and angles.

Bolts

With their help, you can fasten two or more overlapping parts (however, the joined products must be quite thin). This fastening method is convenient to use when building up rafters: two boards are laid overlapped by three of their widths and, after preliminary drilled holes, are tightened with two or three fasteners with nuts and wide washers.

Hairpins

The stud is similar, but has the advantage of having nuts on both sides. This design of the fastener allows you to tighten the fastener without turning the rod. This is convenient if the pin is jammed by the connected parts. In addition, if the rod is long, the force required to rotate it can be very large.

Corners and overlays

Perforated steel plates and angles should not be considered as competitors to anchors.

These types of fasteners complement each other:

using corners, you can join the floor joist boards with beams or crowns without cutting (butt-joint);
plates allow you to connect boards in a similar way when splicing rafters or joists.

Important! To make such a connection reliable, choose a plate with a length of at least five times the width of the board. In addition, to fasten boards with overlays, you should use not “anchors” or self-tapping screws, but bolts with wide washers.

Conclusion

Understanding how to interact with wood different kinds anchors will help you choose the optimal solution to your tasks.

Video: how to install anchors

Hello. Please answer, what diameter are holes made for anchor bolts in wooden beams (the size of the hole should be the same as the diameter of the bolt or less)? Thank you in advance.

Nikolay, Penza.

Hello, Nikolay from Penza!

Anchor bolts are a universal means for fastening parts of various designs. They are used both in combination with stone, metal, and in wooden structures.

Typically, an anchor bolt is a bolt with a wrench head or a screw with a slotted (cross-shaped) slot for a screwdriver. Complete with such a bolt, a washer is most often used, which is placed directly under its head, a sleeve (otherwise a spacer sleeve) with one, two or four longitudinal slots, as well as a cone-shaped nut.

The principle of operation of an anchor bolt is that when you tighten its head with a wrench, the cone nut moves along the thread and enters the sleeve, pushing it apart. Since the anchor bolt is placed in the holes of the parts being fastened (in your case, wooden beams), the sleeve fits tightly to the inner surface of the hole. Which to a fairly large extent guarantees reliable fastening.

The presence of a washer under the head of the anchor bolt prevents the head from falling into the thickness of the wood.

The weakness of anchor bolts is that once they are secured, they cannot, with rare exceptions, be dismantled. Because their components are deformed and the threads become jammed.

The size of the hole that is drilled for the anchor bolt is usually made equal to the largest diameter of the inserted kit. That is, a caliper is used to measure the outer diameter of the sleeve (spacer sleeve) at its largest location. In this case, the entire system (bolt, washer, sleeve, cone nut) should not dangle relative to each other, but should be very lightly tightened.

The anchor is inserted into the combined holes of the fastened parts of the structure to the maximum possible depth, after which, with not very strong blows of the hammer, it is driven completely until the head with the washer stops in the surface wooden beam. After which, using a wrench or a screwdriver with a corresponding bit (or head), it is turned, as they say, “to its fullest extent.”

If the hole for the anchor bolt is made slightly smaller than the maximum diameter of the sleeve, then when driving the anchor, the thread may become jammed and in the future it will be impossible to turn the bolt in the cone nut.

And if the hole is too large, the sleeve with its outer surface may not catch on the inner surface of the hole, no matter how much you twist the bolt.

All of the above does not exclude the possibility of small deviations in the diameter of the holes (about 1-2 millimeters) from the diameter of the anchor set.

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In order to ensure high reliability of the connection using an anchor bolt, it is important not only to select it correctly in size and type of structure, but also to know how to properly fasten such a product.

There is a wide variety of anchor bolts, differing in their design and principle of operation, so it is important to know how to attach a particular type of anchor

An anchor bolt of a classic design provides a reliable connection not only due to the frictional forces of its outer surface with the walls of the mounting hole, but also due to the fact that its spacer sleeve increases in diameter when the threaded element is screwed into it. The reliability of installation of such a fastening element is also influenced by the strength characteristics of the material. building structure, which should also be taken into account.

For all fasteners under consideration, the drill for making the mounting hole is selected according to the diameter of the anchor, with the exception of impact-type anchor bolts.

With nut

The structural elements of this type of anchor bolt are:

• a threaded rod, one end of which is made in the shape of a cone, and a nut is screwed onto the other;
• a spacer screwed onto a stud (its lower end has longitudinal slots on the side surface, which form peculiar petals).

Reliable fixation of such a fastening element is ensured due to the fact that the petals of the spacer sleeve are unclenched, which occurs when they are exposed to the conical end of the pin. In order for the tapered end of such a bolt to begin to enter the bushing and open its petals, a nut is used.

Fasten an anchor bolt with a nut in the foundation or any other building structure made of concrete, performing the following steps:

• drill a hole, the diameter of which should correspond to the size cross section spacer sleeve;
• thoroughly clean the mounting hole;
• carefully hammer in with a hammer;
• By tightening the nut, you achieve reliable fastening of the anchor.

After the installation of the anchor bolt is completed, you can unscrew the nut from the top of the stud and begin installing the required item.

When choosing products of this type, you should keep in mind that they demonstrate their effectiveness only if they are mounted in durable and solid materials (concrete, brick, natural stone, etc.). Manufacturers, in order to ensure high reliability and corrosion resistance of such products, make them from high-quality steel with a zinc coating.

An improved model of this type of anchor bolt is a double-expansion anchor, which, due to its design features, can be successfully fastened not only in durable concrete, but also in hollow and porous materials. Such a bolt has two bushings at once, which expand during the process of tightening the threaded element, creating a more reliable fastening in the wall or foundation.

Wedge

An anchor of this type, the spacer or wedge sleeve of which has a shortened length, is also a modification of a fastener with a nut. The wedge element that expands such a bushing is the reverse end of the threaded part of the bolt, which has a conical shape.

The big advantage of using them is that for their reliable fastening there is no need to maintain the exact diameter of the mounting hole; moreover, it does not need to be cleaned of construction dust. Such a bolt is secured in the mounting hole, and its spacer element is expanded by tightening the nut.

Hex head

The threaded part of such a fastener is a classic bolt, the reverse end of which also has a conical shape. Screwing into the spacer sleeve, such a bolt opens it with its conical shank, ensuring reliable fastening of the product to the wall or foundation.

Such an anchor should be secured by inserting and carefully hammering it into a previously prepared and cleaned hole. Then you need to securely fasten the bolt by tightening its hex head.

Bolts of this type, which may have a hook or ring instead of a hex head, are used to perform installation work for concrete, stone and others building materials with a dense internal structure.

Drums

Anchor bolts of this type consist of:

• a hollow metal rod, on the upper part of which there is a thread for a fastening nut, and the lower part is a spacer sleeve with longitudinal slots on the side surface;
• a striking element (nail), which, when driven into a hollow rod, precisely ensures the expansion of its lower part;
• nuts and washers, which are needed only to secure the required object with such a bolt.

Thus, in order to correctly and reliably fasten such a bolt in a wall or other building structure, it is necessary not only to insert it into the mounting hole, but also to drive an impact element into it, which will open the petals of the spacer coupling.

Taking into account the fact that when installing such a bolt, significant shock loads arise, it is not recommended to fasten it in porous and fragile materials.

Four-segment

The design of such an anchor bolt does not include a wedge part, and the expansion of the spacer sleeve, divided into four segments by longitudinal slots, occurs when the bolt is screwed in, which moves the tetrahedral element in its internal cavity. The four lobes, which are formed by slots on the side surface of the spacer, are initially compressed and form the conical tip of such a bolt. When a bolt is screwed in, which moves a threaded tetrahedral element inside the spacer sleeve, the segments expand, which allows the anchor to be securely fastened in the mounting hole.

The petals of such a product open quite wide and this happens very carefully. That is why it can be mounted in porous and even hollow materials. The threaded element, which is usually not supplied with such an anchor product, can be a bolt with a regular hex head or a bolt top part which is crowned with a ring or hook.

Drivers

A drive-in anchor is the simplest anchor-type fastener, the design of which consists of a spacer sleeve with a conical-shaped internal hole. To install this at the required point of the building structure, it must be hammered into the mounting hole, and then a threaded element must be screwed into it, which will ensure the expansion of the bushing petals.

The material for the manufacture of such fasteners, the process correct installation which can be seen in the video, can be galvanized steel or brass.

An anchor is a combined independent fastener that is fixed in a load-bearing base and holds certain structures. The element is made of aluminum, brass, of stainless steel and other similar materials. The anchor is available in various sizes. Length varies between 55-220 mm, width 8-24 mm.

The anchor is used for bricks, concrete and blocks, natural stone and sheet materials(plasterboard, chipboard, etc.).. There are furniture, facade and foundation bolts, which are respectively used to fasten furniture, facade or. In addition, elements are divided according to the type of “anchor”, installation and fixation.

Types of anchor

• Spacer products are held in the structure due to friction. To increase the strength of the fastener, the installed rod is expanded using a wedge stop with an internal thread or a plastic dowel;
• Thrust bolts have a flared or ribbed portion that provides a strong, secure fit. This anchor is suitable for arranging foundations and concrete structures;
• Adhesive or chemical fasteners are secured using a sticky composition. Most often it is a polymer resin with a hardener;
• The Molly bolt is suitable for insufficiently strong and hollow materials, including chipboard, plasterboard, plywood sheets, and hollow brick. When this anchor is tightened, it begins to push the outer shell apart, which forms a stop.

Anchor for wooden structures

When connecting wooden structures and in wooden construction, it is important to choose the right fasteners that will not only ensure reliable fixation, but will also not damage natural material. In this case, an adhesive or chemical anchor is not recommended, since the resin hardens with large changes in temperature and humidity. This loses grip and renders the mount unusable.

The Molly anchor is only suitable for surfaces where there is a significant void. Such fasteners are used to hang light weight objects on internal partitions or walls made of clapboard, boards or chipboard. Thrust products are used only for massive foundations. These include only the trunk of a growing tree, so these fasteners are not suitable for building a house from logs or timber.

Wood fasteners must have a large thread diameter of over 6 mm to enhance the low mechanical strength of the wooden base. To prevent corrosion and negative effects on wood, fasteners need to be brass-plated or galvanized. Or you need to choose products made from anti-corrosion materials. In this case, wooden dowels are perfect.

Classic metal fasteners are subject to corrosion, which leads to wood rotting. Lumber becomes covered with mold and mildew, swells and softens, and gradually collapses. Therefore, choose anchors and other fasteners made from anti-corrosion materials or with special treatment. How to install a log house with your own hands, what fasteners and materials will be needed for this, read.

How to screw an anchor into wood

It is important to screw the anchor into the wood correctly to ensure secure fastening without splitting the wood. First in in the right place make a hole using a drill that corresponds to the diameter of the fastener along the grooves of the thread. Then the thread is lubricated with solid or liquid soap and the rod is screwed in.

It is important that the depth of the hole made is equal to the length of the rod! With a shorter or insufficient length, the bursting pressure on the wood increases, which leads to the appearance of cracks. “MariSrub” craftsmen will select the necessary fasteners and materials, competently assemble the log house and finish the house. We follow the technologies and rules for the construction of wooden houses!

The MariSrub company harvests wood and produces lumber independently, which guarantees high quality and durability of the products. Each log and timber undergoes antiseptic and protective treatment, which prevents rotting and cracking of natural wood, mold and mildew.

We offer individual design and the change is already finished project. We carry out turnkey work with selection necessary materials and fasteners, prompt and reliable installation of the log house, insulation and waterproofing of the house, installation of the foundation and roofing, installation and commissioning utility networks, finishing and finishing works. We guarantee efficiency and timeliness, quality and durability of construction!

All photos from the article

Are anchor bolts suitable for wood? How to properly anchor a massive product - a lantern, chandelier or hanging bed - to a wooden beam or wall? What other ways can wooden structures be connected? Let's figure it out.

Types of anchors

The word “anchor” itself is borrowed from German language and literally means "anchor". Anchors are used for.

The following types of these fasteners can be distinguished:

Useful: adhesive anchors can often be found under another name - chemical.

Now let's try to analyze which type of anchor is suitable for which:

• The Molly bolt requires a significant area of ​​voids inside the structure. As a result, it can only be used for hanging relatively light products on thin partitions made of boards, lining or chipboard;