The strength, reliability and durability of the foundation support structure largely depend on the quality and correct arrangement of the reinforcing frame. The reinforcing belt can be considered as a kind of skeleton, contributing to a significant increase in the resistance of the base to incoming loads.
Reinforcing belt 
Construction of a reinforcing frame
In preparation for the upcoming pouring of the foundation, you need, firstly, to figure out what kind of reinforcement is appropriate and optimal to include in such a structure, and secondly, in what ways can the connection of individual elements into a single frame be ensured.
You are invited to familiarize yourself with information regarding the listed points and important accompanying nuances below.
Fiberglass frame
Diameter
When choosing reinforcement for the foundation, first of all, pay attention to the diameter of the rods. The dependence is simple: the thicker the reinforcement, the more severe loads it can withstand. When determining the optimal diameter, first of all, the characteristics of the soil are taken into account (the main point is heaving) and the expected weight of the finished building, taking into account the weight of its internal arrangement and residents/visitors.
Reinforcement diameter, weight, total cross-sectional area 
This is how it should be ideally and according to the rules. Along with this, many private developers refuse to draw up design documentation and perform related extensive calculations, adhering to average and generally accepted values. In the case of the construction of relatively small buildings, for example, such as a bathhouse, such an approach is acceptable.
Class
The second important indicator is the class of the reinforcement. For a private foundation, class A-3 material is suitable.
Corrugated fittings A3, steel grade A500S, GOST 5781-82
The fittings of this group are very easy to use (easily bends without the use of special tools), durable and reliable. Less commonly used are rods of class A-2 (they can be bent 180 degrees, A-3 – 90 degrees).
Material
An equally important indicator is the material used to make the reinforcement. Previously, no questions arose regarding this point - the rods were made of durable steel, there were no alternatives.
However, the construction market is constantly developing and expanding. One confirmation of this was the appearance on sale of fiberglass reinforcement.
The rods of this group are characterized by improved operational and practical characteristics. Among the main advantages of fiberglass reinforcement, the following points should be noted:
- high levels of reliability, strength and durability;
- relatively low cost;
- light weight.
The use of fiberglass reinforcement allows you to save on average up to 30-40% on the purchase and transportation of material for arranging a reinforcing frame compared to more traditional steel elements.
The low weight of fiberglass reinforcement makes it possible to transport it in a simple passenger car. The reinforcement has no length restrictions. An ordinary grinder is used for cutting rods.
Important! Before cutting fiberglass reinforcement, be sure to wear protective overalls, gloves, goggles and a respirator.
Fiberglass reinforcement is available for sale in various diameters, suggesting the use of different knitting options. Mainly 8 mm rods are used for longitudinal reinforcement, and 6 mm rods for transverse reinforcement.
Fastening fiberglass reinforcement is most often performed in 2 ways:
- using knitting wire;
- using plastic clamps.
The procedure for implementing both methods remains identical for steel and fiberglass reinforcement and will be discussed in the relevant sections.
Prices for fiberglass reinforcement
fiberglass reinforcement
Wire, clamp, clamp: features of existing fasteners
Fastening reinforcing bars into a single frame can be done using wire, clamps and special clamps. About them in the table.
Table. Materials for fastening reinforcement
| Bonding material | Description |
|---|---|
| The most traditional, budget-friendly and familiar (especially for “old school” builders) material for tying reinforcement. Made from annealed steel. Sold mainly “in bulk”, i.e. in packages (more convenient, since the material is already cut into pieces of suitable length) or in special spools. Package weight and wire length may vary depending on the manufacturer. The most convenient are 5-kilogram packs filled with 40-centimeter pieces of wire. One such package usually contains from 1000 to 1500 pieces of wire. |
|
| The principle of use is not much different from knitting wire - the same methods, similar tools. Characterized by greater ease of use (easier to bend and twist). Costs a little more than wire. It has an increased diameter (on average 4 mm versus 1.2 mm for the wire). To ensure a reliable connection of reinforcing bars, it is enough to use a 20-centimeter clamp at one intersection point. | |
| The most modern option for connecting reinforcing bars. The clamps are made of plastic. They perform best in combination with fiberglass reinforcement. The advantages over steel reinforcement and tying wire are obvious. To fully understand them, you need to pay attention to just one drawback of steel reinforcement - it is susceptible to corrosion. Rust can increase the diameter of a metal rod by an order of magnitude. Its strength, however, does not change for the better. Corrosion causes pores to appear in concrete. Water penetrates into the pores. In winter, water expands and increases the size of cracks. The clamps do not rust, and using them to connect reinforcement is much easier, more convenient, and faster than using wire. There are several types of fasteners available for sale that allow you to connect reinforcing bars in various spatial directions, set up “stands” (as in the image) and solve other problems related to reinforcement. |
Due to the fact that the manual in question is dedicated specifically to tying reinforcement, the procedure for connecting rods with special clamps will not be considered - this process is not tying in the traditional sense and is generally intuitive.
More attention should be paid to the wire and clamps.
First, the wire.
For its manufacture, as noted, low-carbon steel grades are used. The annealed material bends relatively easily and copes well with the tasks assigned to it. Non-galvanized binding wire (black) and its galvanized counterpart (white) are available for sale.
Many craftsmen consider the purchase of galvanized binding wire for arranging a foundation to be an excess and an inappropriate waste of money, arguing that the reinforcing frame after pouring the concrete becomes inaccessible to air, therefore, nothing will rust. At the same time, the occurrence of corrosion, as noted earlier, cannot be ruled out.
- if you decide to use steel reinforcement, you can knit with both galvanized and non-galvanized wire - if corrosion reaches the reinforcing frame, it will not care what “is”, be it reinforcement or wire, and it will not be possible to avoid deterioration in the quality characteristics of the foundation under such circumstances ;
- if you decide to use fiberglass reinforcement, it is better to tie it with galvanized wire - this will minimize the risk of corrosion and ensure a longer service life of the supporting structure.
As for the diameter, the most optimal in terms of ease of use and reliability is the 1.2-1.4 mm option. “One” is weak for the foundation; working with “two” will require extra effort.
Secondly, clamps.
This, as noted, is a modernized and improved version of the knitting wire. They are made of plastic, not steel, so when using such fasteners, the likelihood of corrosion inside the supporting structure is eliminated. Along with this, it is precisely because of the material used to make plastic clamps that many developers have a number of well-founded questions regarding the fasteners of this group.
- Will the clamps be able to withstand the loads created inside the foundation? They can.
- Will the fasteners break over time, disrupting the uniform distribution of loads and generally deteriorating the quality of the foundation? It won't break.
- Is a plastic clamp really reliable? Indeed, but you need to approach the issue of choosing it correctly.
Helpful advice! For tying reinforcement, plastic clamps using steel wire as a core are best. Such clamps are more expensive than steel wire, but they are easy to use.
Important note! Plastic clamps cannot be used for tying reinforcement when carrying out foundation work in the winter - in the cold, the material used to make the clamps almost instantly becomes brittle. The exception is special polyamide fasteners.
Prices for knitting wire
knitting wire
First, remember the main rule: the reinforcement is not connected by welding, but rather tied.
Tying reinforcement - diagram
The bottom line is this: contact of the metal with the electrode helps to reduce the strength of the first so much that even loads occurring with the minimum possible shrinkage of the foundation can lead to catastrophic consequences, the sequence of which is usually as follows:
- reinforcement connection points are destroyed;
- the reinforcing frame disintegrates;
- The concrete structure begins to crack.
How this threatens the structure built on the foundation requires no comment. As an exception, we can only consider special reinforcing bars, the manufacturing technology of which, according to GOST, initially assumes the possibility of subsequent welding.
Secondly, vertical support rods installed as supports for horizontally oriented rods cannot simply be driven into the ground. The correct thing to do is this: the lower reinforcing row is placed on special plastic clamps (the so-called “cup holders”, demonstrated earlier), and the upper part of the vertical rods is connected to the upper row of the frame. Such placement will prevent contact of the rods with the external environment.
Thirdly, the upper horizontal row of the frame must be tied from the inside - this is more difficult, but more correct. Often, uninformed developers make the mistake of leaving the top row of the frame unfixed. If concrete is poured manually, nothing bad will happen in such conditions. When pouring with a special concrete pump, the mixture is supplied under pressure. The pressure created will lead to the reinforcement moving apart, as a result of which the wire may burst.
Fourthly, when performing reinforcement, you need to pay special attention to the corners of the structure, because They are the weakest point of the foundation. In such areas, the rods are not laid at right angles, but are bent. The overlaps are hidden in the wall. It is important that adjacent reinforcing bars do not overlap at one point. The principle is demonstrated in the image.
Reinforcement is considered correct if the result is a rigid spatial frame that can support the weight of a person without visible changes in the structure.
Prices for plastic fasteners for fittings
plastic fixture for fittings
For tying reinforcement, you can use a wide variety of devices - from pliers to special automatic pistols.
The use of pliers and wire cutters with pre-blunted teeth is the most primitive option. Its only advantage is that there is no need to purchase additional devices, however, twisting the wire with such improvised means is time-consuming, inconvenient and tedious. Therefore, we will refrain from considering them.
If you're on a budget, make at least a basic homemade crochet hook. To do this, you will not need anything other than a nail with a diameter of 4-5 mm, a blank for a handle or an old unnecessary screwdriver/awl and a hammer.
To make a hook, do the following:
- prepare your pen. You can use any suitable wooden blank (it is more convenient and easier to drive a nail into wood), for example, from a used household tool. The handle can be made of other materials, the main thing is that it is convenient for you to use;
- drive a nail into the handle, leaving 3-4 cm free;
- cut off the nail head, for example, using wire cutters or another suitable device;
- bend the nail into the hook. This is done as follows: you place the nail on a suitable support, for example, a brick, and gradually use a hammer to give the workpiece the shape of a crochet hook.
The procedure for making a hook from a screwdriver/awl comes down to following the last step of the above tutorial. At the end you should get a device that looks something like this.
Knitting with regular crochet
Having prepared a homemade hook or purchased a ready-made tool at a hardware store, start doing the work. To begin, carefully practice on third-party pieces of reinforcement until you thoroughly understand the principle of operation. It consists of the following:
- a piece of knitting wire at least 200 mm long is folded in half;
- the resulting workpiece is wrapped diagonally at the connection point;
- the hook is threaded into the created loop;
- The free ends of the knitting wire are carefully pulled through the loop. A hook also helps at this stage;
- without taking out the working tool, turn it clockwise until a reliable connection is obtained. Usually several (up to 3-4) turns are enough. Do not twist the wire too much - it will break. Bend the excess parts of the ends of the wire. If the ends are too long, you can cut them off with wire cutters or other suitable tools.
The process is shown schematically in the following image.
For a better understanding of the technology, check out the step-by-step illustrations.
There are several other options for crocheting reinforcement, but the above method is the most reliable, and it is recommended to stick to it.
The method according to which the performer must sequentially perform the following manipulations also works well:
- fold the piece of wire in half, as in the previous case;
- place the folded wire under the reinforcement at the junction;
- grab the loop with a crochet hook;
- bend the remaining free “tail” over the hook;
- twist the resulting loop.
The procedure for performing work in accordance with this method is demonstrated in the following illustrations.
Video – Crochet reinforcement
Knitting with semi-automatic crochet
The semi-automatic, also reversible and screw hook is an improved and more convenient to use version of the above-mentioned device.
The length (as a rule, it is 32 cm) and, in general, the design features of the reversible hook allow for high-quality twisting of the wire with one tightening. The soft rubber handle makes working with the tool even more comfortable and safe, eliminating the likelihood of calluses on your hands.
The procedure for using such a hook is as follows:
- the performer circles the reinforcing bars with wire at the junction (the procedure is the same as in the case of using an ordinary hook, all the necessary information was given above);
- the hook is inserted into the loop;
- the performer pulls the handle of the instrument towards himself.
That's all. As a result of such simple actions, the device, which works like a “spinning top,” quickly tightens the wire, ensuring a tight, reliable and neat knot. The labor intensity and time required to complete the work are reduced significantly.
The tool is suitable for both professional and private use. The reversible hook does not require any special maintenance - you just need to periodically lubricate the working elements with oil.
The operating principle of a screw crochet hook is demonstrated in detail in the following video.
Video – Knitting with semi-automatic crochet
Hand crocheting is a rather lengthy and labor-intensive undertaking. And although the semi-automatic hook, discussed in the previous section, can significantly facilitate and speed up the implementation of reinforcing work, there is an excellent opportunity to do everything much faster and with even less effort. A drill/driver will help with this.
All you need to do is make a hook (an ordinary nail with a diameter of 0.5 cm is suitable as a blank; you have already become familiar with the principle of making a hook in one of the previous sections) and fix it in the screwdriver chuck in the same way as ordinary drills are installed ( The detailed sequence of replacing the working tool should be specified in the instructions specifically for your screwdriver, since these points may vary slightly for different models of tools).
This design will look like this:
The further procedure is no different from the technology of crocheting reinforcement: you still fold the wire in half, put it under the reinforcement, grab the loop with a hook, but twist it not by hand, but with a screwdriver, using minimal effort.
When twisting the wire, the tool experiences virtually no load, so even the most budget drill-driver with minimal power can be used for tying. It is better that the model is equipped with a rotation speed controller. Before work, set it to minimum.
Video - Tying reinforcement with a screwdriver
The gun makes tying reinforcement as fast, simple and convenient as possible - the most advanced models of such guns are capable of creating a connection in less than a second. No preparatory measures are required: the wire is wound on the spool of the gun, the user simply brings the tool to the connection point and presses the corresponding button. Please refer to your specific tool's manual for information on special options and functions.
It looks like this.
There is no need to cut the wire before work: the tool will do everything on its own. This is a big advantage - there is no waste in the form of tying wire scraps, due to which unnecessary costs and operating costs are significantly reduced.
The gun is easy to use - it can be held with one hand and the other, while holding the reinforcement frame, which eliminates the need to attract additional labor in the form of assistants.
An automatic gun, unlike hand tools, allows you to count on constant high quality knitting. By default, all models have functions for adjusting the length of sections and tightening force.
| Gun brand | Weight | Reinforcement size | Price |
|---|---|---|---|
| 1.4 kg | D19xD18 | RUB 48,780 | |
| 1.5 kg | D20xD22 | 60,920 rub. | |
| 2.25 kg | - | 52,000 rub. | |
| 2.4kg | from 20 to 35 mm | 165,000 rub. |
Among the disadvantages of an automatic gun for tying reinforcement, the following points can be highlighted:
- high cost of tools and components (spools of wire);
- the need for preliminary training in working with a gun (in general, nothing complicated, but additional time is still spent. In practice, it is more than compensated by the savings in time spent on twisting the wire);
- inability to use the gun in hard-to-reach places. Even with such a serious assistant, you still cannot completely abandon the use of hand tools for knitting. For example, you won’t be able to tie the rods in the corners of the reinforcing frame with a gun. In addition, you can only insert a hook between the whips to tie the 2nd layer of the reinforcing frame.
Video - Knitting reinforcement with a gun
A few words about clamps
To knit reinforcing bars, as noted, you can use special clamps. They look like this.
Thus, one end of the clamp is free, and the lock is located on the other.
The procedure for using the clamp is as follows:
- the product is inserted under the reinforcing bars at the intersection;
- the free end is pulled into the hole in the latch until it stops;
- the position of the fastener is fixed, thereby ensuring the connection of the reinforcement.
There are many types of clamps available on the market. In combination with reinforcement, products made from polyamide 6.6 perform best. Such clamps “feel” normally in the temperature range of -40-+85 degrees, without bursting, cracking or spreading. A good clamp should be elastic. You can check this parameter as follows: take the product and bend it in half. If a crack appears at the bend, stop using such a clamp.
Special guns are available for sale to make the process of arranging clamps simpler and faster.
Prices for cable ties (clamps)
cable ties
Video - Tying reinforcement with clamps
Similar fasteners include metal clips (connectors) for connecting reinforcing bars into a single frame. One end of this mesh is equipped with a hook, the other with a loop. The diameter of a steel clip is on average 2-4 mm. At the point where the reinforcement is tied, the hook and loop engages the lower steel bar. The middle part of the clamp presses the upper rod to the underlying one.
Tying reinforcement with a paper clip 
Clips for tying reinforcement
Happy work!
Video - Knitting reinforcement for the foundation with your own hands
A strong and high-quality reinforcing mesh is needed to maintain the spatial shape of the foundation when it is poured. Therefore, you cannot cook it - otherwise, as experts explain, “the iron crystal is damaged.” And it doesn’t matter whether a large building or a compact bathhouse is being built, only tying reinforcement for the foundation is possible, and of high quality and with the right material.
But today there are quite a lot of ways to knit reinforcement. But, in general, most often it looks like this: the network is knitted in sections outside the trench, and then these sections are simply tied to each other. You can, of course, knit at the bottom of the trench, but for this the reinforcement must be secured in advance. After all, the main thing is that it does not sink to the bottom of the trench - and for this, experienced builders use special holders (sold on the market).
What to knit with? Tie wire VS plastic clamps
What is better for tying reinforcement: regular wire or fashionable plastic clamps? Let's figure it out together.
Steel wire: where to get it and how to make it yourself
Foundation binding wire is made from annealed low carbon steel. It is soft to bend and easy to use. The color is white - galvanized - and black, without any coating. By the way, interestingly, many craftsmen consider beautiful galvanized wire to be used for a foundation as a real excess - after all, there is no access to oxygen in concrete, and therefore there can be no corrosion.
Expert advice: if you suddenly bought a knitting wire in a store, but it doesn’t bend well, you don’t have to return it - just warm it up in a fire for half an hour and then cool it in the air.
What diameter should I use for the wire? Experienced builders say that the most convenient and durable option is 1.2-1.4 mm. A two takes a lot of effort, but a one is too weak.
Here's how you can get hold of tying wire for a foundation. We take an old truck tire and burn it. This tire contains metal cord - it is this that is used in the new capacity. The only point: tires from imported trucks may contain synthetics instead of metal. This is easy to check: use a knife to cut through the inner side, the one adjacent to the rim. Did the knife hit the metal? So, the wire will work. Didn't resist? Then the tire will simply burn in the fire, and that’s it.
Plastic clamps: pros and cons
Most builders look at the recently introduced plastic clamps with some apprehension - will they then withstand the load in the foundation? Won't they break? How reliable are they really?
And the advantages of this material, of course, are pleasing: the simplicity and speed of tying, the cost is not much more expensive than tying wire.
And the most popular in this regard today are plastic clamps with a heart made of steel wire. They are used for attaching pipes for cables to fences, and when installing perimeter security systems. They are more expensive, but they are especially convenient to use.
Another point that not everyone knows about: the foundation tied with plastic clamps cannot be left in the winter. From frost they immediately become brittle and burst.
How to knit? 4 most popular methods
A simple simple hook for tying reinforcement can be made from wire 3-4 mm in diameter - for example, from an electrode for electric arc welding. Of course, they won’t be able to knit quickly, but it’s quite tolerable. But let’s share this trick: make a nail attachment for a screwdriver - in the shape of a hook, like on a clothes hanger, and use it to tie around the reinforcement. This way everything will work out twice as fast, and your hands will get tired much less.
And the essence of the technology, how to properly knit foundation reinforcement, is simple. We place two rows of wire pendicularly. Next, we use a homemade machine, where the reinforcement is clamped with boards and we knit it manually, or we use a gun for tying reinforcement, which can be purchased at a construction supermarket. The main thing is that the rods do not sink to the bottom of the foundation, and to do this we either lay a brick or stick the ends of the mesh directly into the soil. Next, there are differences in how and where to bend the wire itself. Choose the method with which tying reinforcement will be more convenient for you!
Method No. 1
Here's how to knit foundation wire by hand:
- Step 1. Take the wire in your hands and fold it in half.
- Step 2. Bend around your finger about one-third of the way through the loop.
- Step 3. Now we put it on the reinforcement and insert the hook into the loop.
- Step 4. Turn the hook and grab the second end of the wire with it, pull the other end of the wire toward you.
- Step 5. Take out the hook and bend the ends. If they turn out to be long, cut them off.
How many revolutions will need to be made will be determined practically. If there is too little, the harness will be weak; if too much, the wire will break. Usually - from three to five turns.
Method No. 2
Work order:
- Step 1. In this version, the wire is also folded in half.
- Step 2. Press it against the rod with your fingers and bend the ends towards you.
- Step 3. Insert the hook, twist, remove and bend the ends.
Here the wire holds much better and more reliably.
Expert advice: the most common mistake when tying reinforcement is long twists. To prevent this from happening, you just need to bend the wire before rotating the hook - so that it has time to make 3-4 turns.
Method No. 3
Work order:
- Step 1. Take a piece of wire and fold it in half.
- Step 2. Start from below.
- Step 3. Grab the loop with the hook.
- Step 4. Bend the remaining “tail” over the hook.
- Step 5. Twist the resulting loop.
Method No. 4
But, according to reviews, the most convenient way to knit wire on reinforcement with your own hands:
- Step 1. Insert the hook into the loop and grab the other end with it - the one that you hold with your hand.
- Step 2. At the same time, bend the wire down through the hook.
- Step 3. Pull the hook towards you and twist it several times. That's all!
This method has a fairly significant advantage - the left hand remains free and you can use it to hold the reinforcement, which is very convenient.
We knit reinforcement with special guns
And they come in a wide variety - electric and battery-powered, from a variety of manufacturers. The Japanese were the first to come up with such a miracle of technology - thanks to their device, the wire on one node is twisted within a second and strictly within a certain tension force: not weakly, but not so much that it breaks.
There's just one problem: these pistols are very expensive. And here Russian craftsmen get out of the situation as best they can: someone buys and then resells a pistol, someone prefers a cheap Chinese counterfeit (enough for one foundation), and someone is looking for an opportunity to rent such a pistol - and In fact, such a possibility exists.
But it doesn’t matter which method or tool you choose - the main thing is that the reinforcement is connected conscientiously. Then the foundation under the bathhouse will delight you for many years with its strength and the absence of any cracks.
Construction symbiosis. It seems like a concept from biology. Animals and plants enter into symbiosis, that is, mutually beneficial cooperation. One, for example, can serve as a home for another, receiving useful substances or protection from viruses from the “tenant”.
What is the construction symbiosis? Let's look at an example and. Steel rods give rigidity to the latter, saving it from destruction. Concrete saves the reinforcement from oxidation and rust, protecting it from the harmful effects of the atmosphere and moisture on the metal.
For symbiosis to work, you need to learn knit reinforcement correctly. Without preliminary coupling of its rods, walls and interfloor ceilings are not poured. Why? More on this and more below.
Why knit reinforcement
You can understand why to knit reinforcement by knowing the diagram for pouring reinforced concrete structures. First, the metal frame is installed. However, there are also composite reinforcement. The latter is lighter in weight and is rolled into coils.
The first is unbending and heavy. But the principle of operation of classic and modern frames is the same. A kind of network is made from rods in the center of the foundation, wall, concrete. The reinforcement should remain in the center.
By moving to the edges of the fill, the frame will redistribute the loads in the final structure and become vulnerable. Close to the concrete surface, water vapor can reach the reinforcement, causing corrosion of the metal. That is why the rods are tied together so that the base does not “float” under the concrete mixture being poured.
How to knit reinforcement for a foundation
Question, how to knit reinforcement for a foundation, is popular because laying rods in the foundation is always required. A metal network is needed even under a private house, not to mention multi-apartment high-rises.
Under the latter, it is customary to pour monolithic foundations, that is, solid slabs. For private houses, it is often enough strip foundation. How to knit reinforcement for both? Same. There are several ways:
Classic reinforcement knitting
We take steel wire with a diameter of 0.8 to 1.2 millimeters. The exact diameter depends on the width of the reinforcement bars. It ranges from 6 millimeters to 8 centimeters. The degree of strength that the metal will impart to the concrete pour depends on the diameter.
Classic crochet reinforcement
However, this strength is also related to the quality, as well as the type of knitting. In addition to manual connection of reinforcement, there is the option of welding. The latter is rarely resorted to, since the docking turns out to be rigid.
The frame has no gaps for a step “right” or “left”. Such movements are necessary when there are critical loads on the foundation. Where welded joints break, knitted ones will only stretch, maintaining the integrity of the structure.
The main load in the foundation is carried by the longitudinal reinforcement bars. Transverse – their support. Connect the corners of the frame and the intersection of the rods. Usually, the fastening wire is worked with pliers. They twist the ends of the harness, securely fixing it. The shape of the fastening is a single loop.
Knitting reinforcement with a hook and a screwdriver
Crochet reinforcement does not imply a fishnet, as some ladies might think. The hook for the foundation frame is not so much a knitting needle as it is a pair of wire cutters that remove unnecessary ends of the wire.
Tying reinforcement using a screwdriver
Before this, the fastener is picked up and twisted into a bundle. A hook also helps to secure the loop. He picks up the wire. All that remains is to make rotational movements.
They are made manually or using a screwdriver. The latter speeds up the knitting process by about 5 seconds on each loop. For the method to work, the ends of the wire are inserted into the screwdriver chuck and turned on.
Knitting reinforcement with a gun
A rebar gun is a battery-powered electrical device. The device speeds up and partially automates knitting. One knot with a gun takes 1.5-3 seconds, as opposed to at least 10 with other methods of connecting rods.
Knitting reinforcement with a gun
A microchip in the gun regulates the tension of the wire during tying. Convenient, because with manual connection it is rarely possible to make identical nodes. One may be tight and the other flimsy. The wire for tying in the gun is wound on a drum. The part is removable. This saves working time. A new drum immediately takes the place of the old one.
You have to pay for the convenience of working with a pistol. The device is expensive. Therefore, a reinforcing gun is used, as a rule, on large construction sites that need to be completed in a short time. In private housing construction, they prefer hooks and pliers.
Tying reinforcement with staples
A staple is a piece of wire. It is already folded into a loop. All that remains is to tighten it. As a result, the process of knitting a joint is accelerated by 3-4 times. Minimal skill is required to work with staples, and a beginner masters the process in just a couple of hours.
Tying reinforcement with staples
In addition, each bracket is of a standard size, which ensures uniformity and stability of connections. The ease of drawing up an estimate is also attractive. One staple is needed for one joint of reinforcement bars.
When purchasing wire in coils, you have to take into account the footage and split it into the approximate length of one fastener. In general, if you plan knitting reinforcement with your own hands, staples are a convenient and affordable option. The price tag for blanks is slightly higher than for regular wire. But the time saved on mating covers the costs.
Tying reinforcement with clamps
Clamps are plastic “straps”. They have something like plaques on them. The end of the belt is inserted into the plaque and tightened. Fastening is not as reliable as wire fastening, but it is sufficient for fastening rods in the foundation of a private house.
Tying reinforcement with plastic clamps
In addition, plastic has advantages over steel reinforcement. The polymer does not rot, even if it comes into contact with water. In addition, working with clamps is simple and non-traumatic. You can still get hurt and scratched with wire.
An additional advantage of clamps is self-sufficiency. No additional tools are needed to work with plastic belts. The only problem is that in sub-zero temperatures it is difficult to use polymer fasteners. Plastic hardens in the cold. The connections are poor. But you can work with wire in any weather.
Most often people think about clamps when deciding how to knit fiberglass reinforcement for a foundation. The design is 100% polymer, excluding the weaknesses of metal in terms of intolerance to atmospheric phenomena and moisture. However, there are also complex clamps.
A thin wire is implanted into these. Plastic protects it and makes it easier to work with. But clamps, even ordinary ones, are about 3 times more expensive than wire for the same number of fasteners.
Knitting reinforcement with a double knot
The tying methods already described provide sufficient fixation of the reinforcement rods laid in the foundation pit. However, if the frame needs to be made separately and then moved to the main place, it will fold. Welding provides rigid fixation, but its disadvantages have already been discussed.
It is advisable to leave minimal play in the rods. Double knitting comes to the rescue. It requires hard training and involves simultaneously tightening steel rods on both sides. The scheme is difficult to explain in words. It's easier to watch a training video. It should have 5 steps. Exactly as much in double knitting.
There is also a scheme for connecting two spatial frames into one volumetric one. It already consists of 6 steps. Having mastered them, you can prepare reinforcement in advance while the foundation pit and formwork are being prepared. Then all that remains is to move the frame.
How to knit corners of foundation reinforcement
Knitting the corners is a separate issue, since they account for the lion's share of the load. In addition, angles are right, acute and obtuse. The acceptable method of knitting depends on the configuration. Blunt connections are made rigid, overlapping.
Correct knitting of foundation corners
It is produced by bending one of the free ends of the reinforcement. Afterwards, the inner horizontal rod is attached to the same outer one. An internal horizontal rod is attached to the resulting bundle.
Fasten with a paw. In length it is equal to 35-50 diameters of the longitudinal reinforcement. As for the step between the corner transverse rods and the vertical ones, it is equal to 3/8 of the height of the foundation.
The corners of the junctions in the foundation are fastened with U- or L-shaped clamps. 90-degree joints of reinforcement bars are usually fixed with L-shaped anchor elements. Almost always the process consists of 5-6 steps. To master them means to provide the house with a bright, that is, strong future.
The combination of concrete and reinforcement provides any reinforced concrete structure with strength and durability. In order for the finished metal frame to last a long time and withstand serious loads, you need to know how to knit reinforcement.
Using special knitting wire
To quickly and reliably make the strapping, a special baked steel wire of round section with a diameter of 0.8 to 1.2 mm is used to fasten the reinforcing elements. It bends easily, fits tightly to the joint, and stretches well (that is, it does not tear when knitting). When working with such material, the knitter does not require any special skills. This method is successfully used both for tying the reinforcement of a reinforced concrete monolithic slab and for any foundation. How to quickly knit reinforcement, what materials, tools and equipment will be required for this.
Application of hooks
To work with wire, you can use: a manual crochet hook (it can be easily purchased at any hardware store), a homemade hook for tying reinforcement, a semi-automatic mechanical hook (more expensive than a regular manual one) or a crochet hook made using a screwdriver.
How to make a hook for tying reinforcement:
Option #1:
We take a thick electrode or a metal rod of a suitable diameter, sharpen one end of it and bend it at the desired angle. We bend the handle from the second end of the rod (if desired, you can wrap it with electrical tape). The hook for tying reinforcement with your own hands is ready.
Option #2:
The material for production is a metal rod, both ends of which are sharpened. On one end of the rod we place a round wooden blank for the handle (with a drilled hole in diameter slightly smaller than the diameter of the rod); We bend the second end of the rod to the required (convenient) angle.
Option #3:
An old screwdriver (or a construction awl) is suitable as a starting material, the metal end of which is sharpened. Then we bend it to the required angle and get a hook for knitting reinforcement with a comfortable handle.
On a note! The photo will help you easily make hooks for tying reinforcement.
Tying reinforcement with a screwdriver significantly speeds up and facilitates the work. We clamp a hook for wire tying reinforcement, made from a thick nail, into the chuck. By adjusting the rotational force of the screwdriver, you can easily achieve the required joint density. How to knit the reinforcement cage: with homemade tools or purchased ones (or both) - decide for yourself.
How to crochet
The methods of tying reinforcement are quite simple and understandable. Scheme of step-by-step knitting of reinforcement:
- We cut the wire into pieces (we select the size experimentally depending on the diameter of the rods).
- Fold the prepared piece in half.
- We bend the double workpiece around the intersection of the reinforcing bars.
- Insert the hook into the loop and place the loose ends on it.
- Rotate the hook (usually 3-4 rotational movements are enough) until a tight twist is obtained.
Attention! You can tie the reinforcement using the above technology using any type of hook.
There is another way to crochet reinforcement - overlapping.
- We cut a piece of wire twice as long as in the first case.
- Fold the piece in half and in half again.
- We place the double bend on the top bar.
- We place two double pieces under the lower bar and lift it up.
- We insert the hook into the loop and press the two free ends to it.
- Rotate the hook and crimp the joint. If we use a mechanical hook, then with force we pull the handle towards ourselves. We obtain a tight twist due to the fact that the translational motion is converted into a rotational motion by means of a worm gear.
Using a knitting gun
A gun for tying reinforcement greatly simplifies the work of creating any reinforcing frame.
Convenience and advantages of use:
- the cassette is inserted inside the device;
- it is supplied automatically;
- the knitting gun is powered by a built-in battery;
- correct knitting of reinforcement with minimal use of manual labor;
- An automatic gun for tying reinforcement allows you to make all twists with the same tension.
But such a convenient and useful device has disadvantages:
- impossibility of carrying out work in hard-to-reach places;
- a gun for tying reinforcement is expensive, so its use is economically justified only when carrying out large volumes of work.
Table with approximate prices for the main models available for sale on the construction market:
| Model | Ø fittings (mm) | Unit production time (sec) | Number of nodes from one battery charge | Approximate price (RUB) |
|---|---|---|---|---|
| GS308-6512 | 6.5÷12 | 0,8 | 1000 | 19000÷21000 |
| GS308-1016 | 10÷16 | 0,8 | 1000 | 22000÷24000 |
| GS24T | 6÷24 | 0,8 | 1000 | 26000÷28000 |
| GS34T | 8÷34 | 0,8 | 1000 | 28000÷30000 |
| RT308V | 4÷19 | 0,8 | 1100 | 31000÷35000 |
| BM400 | 10÷29 | 1,0 | 2000 | 44000÷46000 |
| BM200 | 9÷21 | 0,85 | 2000 | 28000÷30000 |
| KW-0039 | 10÷22 | 0,8 | 1200 | 47000÷54000 |
| RDL40 | 12÷32 | 0,9 | 3000 | 43000÷45000 |
| RDL20 | 9÷21 | 0,9 | 3000 | 41000÷43000 |
| PVA-32 | 6÷18 | 1,6 | 450 | 44000÷45000 |
Pliers and pliers
For tying, ordinary pliers, pliers (with slightly blunt cutting edges) and special pliers for tying reinforcement (manual or automatic) are often used.
Knitting reinforcement with pliers and pliers according to production technology is no different from fastening reinforcing bars using hooks. The only difference is that there is no need to form a wire loop.
Strapping using electric welding
Advantages:
- A fairly reliable way to tie reinforcing bars.
- High speed of work completion.
- Less labor-intensive process than hand knitting.
Flaws:
- Under the influence of high temperature during welding, the physicochemical properties of steel change (the crystalline structure of iron is disrupted). At the joints, the bending and tensile strength of the reinforcing bar is significantly reduced. Ultimately, this leads to a decrease in the reliability of the entire reinforcing frame.
- significantly increases the rigidity of the frame made of reinforcing bars. When compacting the solution with vibrators, there is a risk of deformation or destruction of rigid welded joints.
- The frame metal in the area of welding seams is more susceptible to corrosion, which reduces the durability of the entire reinforced concrete structure.
- To carry out welding work, special equipment is required.
- The site where such work is carried out must be connected to the power supply, which is not always possible (especially during suburban construction).
- Work can only be carried out by a qualified specialist (welder). How firmly and reliably the frame made from steel reinforcement is knitted depends on his experience and qualifications.
Tying with metal staples
The reinforcement can be tied using special metal staples.
Advantages:
- high speed of connection execution;
- no tool is required for tying reinforcement (everything is done by hand);
- even an untrained person can do the job;
- equal density of connected compounds.
Flaws:
- the need to purchase a set of special staples for the production of tying reinforcement of a certain diameter;
- limited area of application: only for fastening simple cross connections;
- insufficient fastening strength (mainly suitable for light horizontal structures, for example for reinforcing screeds).
Tying with plastic clamps
Knitting reinforcement using plastic clamps is a simple and convenient method for creating a reinforcement frame.
- plastic is not subject to corrosion;
- ease of installation;
- high knitting speed;
- low cost;
- there is no need to use special tools.
- work cannot be carried out at subzero temperatures (plastic becomes brittle);
- the strength of the connections is questioned by many professionals;
- a fairly large elongation coefficient of plastic can lead to a decrease in the rigidity of the reinforcing frame (or a violation of the geometry).
The rules on how to knit reinforcement for a strip foundation and for a foundation are the same. The length of a standard reinforcing bar is 6 meters. Very often they have to be joined. The overlap of the reinforcement during tying should be 40÷50 cm, the rods should be tied together evenly in 3-4 places.
The same requirements apply when strengthening corners and junctions with L-shaped and U-shaped additional reinforcing elements.
Metal knitting can be done not only in the formwork, but also in separate fragments (made in a place convenient for you), which are then lowered into a box.
Important! It is necessary to tie the reinforcement of individual fragments together.
The combination of reinforcement for the foundation and the correct choice of its diameter are the main factors influencing the strength of the foundation of the future structure. When tying reinforcement for the foundation, special attention must be paid to the tightness of all connections.
This video will help you understand how to properly knit foundation reinforcement:
In custody
How to tie reinforcement to a foundation or under a floor screed: using a gun for tying reinforcement or a regular homemade hook, the decision is yours and depends on the amount of work and financial capabilities. The main thing is to follow the rules and technology, then the reinforcing frame will be reliable and durable.
Reinforcement of reinforced concrete structures is a key factor determining their reliability and durability. Concrete structures are reinforced with reinforcement cages assembled using binding wire, which we will discuss in this article.
The publication presents wire for reinforcement, discusses the scope of its use, types and features of application. Instructions for calculating material consumption and recommendations for its selection are provided.
1 Knitting wire - where and why is it used?
Reinforcing wire is used in the field of individual and industrial construction for the manufacture of frames used to reinforce reinforced concrete structures. By means of a knitting wire, adjacent reinforcement bars are connected at the point of their overlap.
The material can be used in assembling the following types of frames:
- foundation (strip, monolithic, columnar);
- ceilings (basement and interfloor);
- floor screeds.
The most common wire for reinforcement in monolithic construction. In the industrial production of reinforced concrete products - piles, floor slabs, reinforced concrete blocks, their frames, in order to save time, are joined using spot welding.
1.1 How to calculate material consumption?
According to the provisions of SNiP, the consumption rate of tying wire when assembling a reinforced frame is 30 cm per connection or 4 kg per ton of reinforcement. To find out how much material you will need to use, you need to determine the number of reinforcement joining points in the frame and calculate the total consumption.
As an example, we give the calculation of wire consumption for reinforcing a strip foundation. We use a conventional foundation size of 5 * 6 m, it will have 2 belts of longitudinal reinforcement - upper and lower, 3 rods in each, connected by vertical and transverse jumpers with a pitch of 40 cm.
Algorithm for determining flow:
- We calculate the perimeter of the frame: 5 * 6 = 30 meters.
- We determine the number of jumpers based on a step of 40 cm: 30/0.4 = 75 pcs.
- Each jumper will have 6 joining points (3 rods on each belt), determine the number of connections: 75*6 = 450 pcs.
- We calculate the consumption of the binding wire: 450 * 0.3 = 135 m.
In total, to connect the frame rods we will need to use 135 meters of material. Similarly, by determining the number of connections and multiplying them by the standard consumption, you can calculate the total wire consumption for assembling a reinforced frame of any configuration.
2 Classification and varieties
Reinforcement wire is classified into varieties according to the following parameters:
- presence or absence of a protective coating;
- heat treatment;
- strength class.
Depending on the presence of a protective coating, the material is divided into two types: made from ordinary and. The coating is applied by hot-dip galvanizing, which involves soaking coils of wire in baths of molten zinc.
Material with a protective coating is divided into two classes - 1C and 2C. The differences between them lie in the thickness of the galvanizing layer; in class 2C material, the protective layer is much thicker: for comparison - 155 versus 85 g/m2 in wire with a diameter of 6 mm. An alternative to galvanized materials is MNZHKT wire made of a copper-nickel alloy, however, its use in construction is unjustified due to its high cost.
According to the type of hardening, reinforcing wire is classified into untreated and annealed (marked with the letter O). The essence of heat treatment is to heat the material to a given temperature in a blast furnace and then cool it. As a result of annealing, the crystalline structure of the metal changes and the internal stress of the steel is destroyed, which provides increased elasticity and mechanical strength of the wire.
Depending on the strength class, products are classified into two groups B-1 (regular) and B-2 (high-strength). The difference between them lies in the brand of alloys used; low-carbon steel is used for the manufacture of V-1 wire, and steel with an increased number of components is used for V-2. Material B-2 is used to connect frames made of prestressed reinforcement, while class B-1 is intended for the installation of non-prestressed structures.
2.1 Dimensions and weight
The diameter of the material depends on the presence of a protective coating - galvanized wire is available in diameters of 0.2-6 mm, uncoated - 0.16-10 mm. From the factory, products are supplied in skeins (weight from 15 to 250 kg) or reels (500-1500 kg). The skein should consist of one piece of wire, the coil - no more than 3.
Here is a table of knitting wire weight 1 meter, BP brand, the most popular on the market:
- VR-1 (diameter 1 mm) - weight 0.012 kg;
- VR-2 (diameter 2 mm) - weight 0.025 kg;
- VR-3 (diameter 3 mm) - weight 0.06 kg;
- VR-4 (diameter 4 mm) - weight 0.1 kg;
- VR-6 (diameter 6 mm) - weight 0.23 kg.
A characteristic feature of the VR brand is the presence of corrugated walls, due to which the adhesion (adhesion) of the material to the reinforcement bars increases, which has a positive effect on the overall strength of reinforced concrete structures.
Wire "Cossack"
"Recently, wire for tying reinforcement with rings, also called “Kazachka”, has become widespread on the market. It is produced in the form of lengths of 8, 10, 12 and 14 cm, at the ends of which there are rings for a hook for tying. Connecting reinforcement with “Kazachka” is carried out much faster than with a standard analogue, since there is no need to cut and independently form rings. The material is supplied in the form of spools consisting of 1-5 thousand pieces.
2.2 Knitting reinforcement with wire (video)
2.3 How to knit?
To assemble a frame from 10-14 mm reinforcement bars you need use wire with a diameter of 1.2-1.4 mm. If the material has poor elasticity, the coil must be kept in a fire for 20-30 minutes, and then allowed to cool at natural temperature. You can use products with a smaller diameter, but in this case, when making a connection, you will need to bend it twice.
