Reinforced seam. We close the seams of drywall

In modern construction, there are different ways to connect reinforcement:

• mechanical;
• by welding;
• overlap without welding.

Benefits of mechanical docking

This method is the most profitable, respectively, and the most commonly used. If we compare the process of mechanically joining rebar with overlapping rebar, the main advantage here is that there is no significant loss of material. Overlapping leads to the loss of a certain amount of reinforcement (approximately 27%).

If we compare the mechanical connection of reinforcement with docking by welding, then in this case the speed of work wins, which takes much less time. In addition, welding should only be carried out by professional welders in order to avoid poor quality work, which in the future can lead to negative consequences. As a result, if you carry out mechanical docking, you can significantly save on the wages of qualified craftsmen.

Even as a result of this method of connection, a fairly solid structure is obtained. It is possible to obtain an equal strength connection using this method under various weather conditions and at any time of the year.

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Rebar mechanical connection process

Scheme of reinforcing the foundation with stiffeners: 1 - Mesh of working reinforcement, 2 - Vertical reinforcement.

To carry out the docking of the reinforcement mechanically, you will need an appropriate tool - a hydraulic press.

From the materials you will need:

• pressed and threaded sleeve;
• rebar bars.

The mechanical connection technology is quite simple and is as follows:

• a steel sleeve is put on the reinforcing bar;
• it is compressed by a hydraulic press;
• for the second rod, the process is repeated again.

As a result, it takes very little time to create a mechanical connection. Instead of couplings, it is allowed to use thick-walled steel pipes or couplings that have a partition in the center, which greatly simplifies installation.

A strong mechanical joint is possible for reinforcing bars of different diameters. This is due to the presence of interchangeable dies in the hydraulic press.

To perform this type of docking, you do not need the help of professionals; almost everyone can cope with the task. But there is one important condition: two people must do the work at once.

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Docking reinforcement by welding

Despite the popularity of mechanical docking, the connection of reinforcement by welding is also no less in demand in construction. There are several ways of arc welding:

• extended seams;
• multilayer seams without the use of other technological elements;
• with forced formation of a seam;
• point.

To perform this type of work, you will need the following tools:

• welding machine;
• electric holders;
• guards;
• protective glasses;
• hammer, chisel;
• metal brushes;
• skimmer;
• steel ruler;
• plumb, stigma.

The main working material is reinforcement.

Reinforcement welding with extended seams is used to connect horizontal and vertical rods. This type of docking is possible with overlays or overlap. The overlap connection is carried out with extended seams, but a variant with the use of arc points is also possible. It is also possible to connect reinforcing bars with a short and long overlap or a double-sided and one-sided seam.

Welded joints of overlays with reinforcing bars are short or long. In this case, it is allowed to shift the lining along the length. Welding of fittings is carried out with various flank seams.

In the process of welding with double-sided seams, hot longitudinal cracks sometimes occur during the application of the second joint on the other side. To prevent their occurrence, it is necessary to carefully select the type of electrodes and strictly maintain the technological mode of welding.

Welded broaching seams are multi-pass or single-pass, it depends on the diameter of the joined rods. The current for arc welding is selected depending on the type of electrodes. It is important to take into account one condition: in the process of welding reinforcement located in a vertical position, the current is 10-20% less than for rods in a horizontal position.

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Welding with multilayer seams

In the presence of highly qualified welders or with small amounts of work, welding with multilayer seams without the use of forming elements is often used for joining reinforcement. This method is most suitable for connecting fittings located in a vertical form. Bevel angles, their direction, blunting and dimensions, cutting shapes, gaps between the rods are standard.

Welding of reinforcement with multilayer seams is carried out using a single electrode. The welding seam is first applied on one side of the groove, and then to the full width on the other. During the melting of the groove, it is necessary to periodically clean the deposited metal from slag.

The mode for this type of welding is set to the one indicated in the passport data of the electrodes. In this case, they are usually applied with a calcium fluoride coating.

As you know, the seams at the joints of drywall should not be inferior in strength to the drywall itself. Otherwise, with temperature and other deformations of drywall, cracks may appear at the seams, which will negate all the work done. In this article I will tell you in what ways you can close the joints on the seams of drywall, and how to do it preferably.

In the past few years, when reinforcing drywall joints, builders mainly use 2 types of materials - this is a reinforcing self-adhesive "serpyanka" mesh, a gossamer glued on glue, or perforated construction paper tape. Both of these options are quite common and have slight differences in the installation method, and also have different quality. Consider both options, and I will tell you why paper tape is preferable.

Option one, using sickle to reinforce the seam

We use a self-adhesive sickle, stick it on the joint of drywall sheets along the entire length.

We breed putty for drywall, it is better not to save on it and purchase gypsum putty from well-known manufacturers, such as Knauf.

We apply the putty on a wide spatula and putty the seam with the mesh, I prefer to work in several steps, making the widest possible layer of the solution.

The wider the seam is smeared, the less it will protrude on the wall and the less it will be visible in the end. Therefore, do not strive to make narrow seams, as thick as a tape or a little wider, the normal width is 10-15cm.

After drying, the seam is ready. However, although the mesh method is the simplest, it has its drawback - the lack of a margin of safety. Due to its qualities, the reinforcing mesh can stretch in one direction or another in the wake of the drywall, which will subsequently lead to the appearance of cracks in the seam. Repairing such seams is a rather laborious task, and if the room is affected by temperature or moisture, the choice in favor of a reinforcing mesh, sickle, is not the best.

Here it is necessary to say a few words about drywall, or rather about its edge. At the moment, almost all good drywall has a thinned PLUK edge, this is the optimal type of edge.

The rounded edge leaves a lot of space for putty, which has a positive effect on the strength of the seam.
However, if the sheet originally came without an edge, or if a piece had to be cut off, such an edge must be recreated. This can be done either with a special edging knife or with an ordinary knife (with caution).

Option two, using reinforcing paper tape

Paper tape for reinforcing drywall joints is not ordinary paper tape. Firstly, it is reinforced with fiberglass, but secondly, a high-quality tape has micro-perforations that allow air bubbles to escape from under the tape, and thereby create a better seam. It is this tape that is preferably used when reinforcing seams. In general, the paper tape is stronger than the mesh and holds normal loads when drywall moves from humidity and temperature changes, which helps to avoid cracks in the seams.
Since the paper tape does not have an adhesive layer, putty is first applied directly to the seam, then the tape is glued, and the finishing layer of putty is applied on top.

We apply putty in the same way as when using a grid, evenly filling the seam.

We glue the tape on the putty layer, try to fix the tape in the center of the seam. Iron the tape to stick and release the bubbles. It is important that the extra putty is gone, but the necessary one does not come out. You can only understand this with experience.

We close the tape with a finishing layer of putty. Do not overdo it, the layer should be thin so as not to form a bump on the wall.
This completes the reinforcement of the joint. Not much more difficult than using a grid, but much more reliable.

How to close a corner joint

Often they make all sorts of complex drywall constructions. Here a metal profile for drywall, putty and paper tape will come to the rescue.
Especially for an example, I will show on this small piece of drywall by the window how this is done. We mark the holes for the profile and fasten it to the drywall.

We also pass with a spatula with putty one side of the joint, covering the profile, then we do the same with the second side.

Glue the paper tape to the putty.

We pass with a layer of putty from above, trying to make the most even transition from the sheet to the edge of the metal corner, you can try to completely cover it with putty.

That's all, the corner is ready. For reliability, at the end of the repair, it is necessary to glue a plastic protective corner so that the putty does not crumble from accidental impacts. Here's another good one.
This is where my story comes to an end, I tried to talk in detail about how you can seal the seams on drywall, explained why it is better to use paper tape and not mesh. The choice of which technology to use in your repair is always up to you. Thanks for watching and good luck with the repair!

What will be required in order to correctly, quickly and beautifully reinforce the seams on drywall, internal and external corners? To begin with, you should not use such a sickle for this.

Even with a little effort, it spreads. No quality can be expected from her. It is better to use paper for seams.

She has a place of inflection, and this place should be placed along the drywall seam.

You should not use PVA glue, patch up paper, we will use the Sheetrock universal putty. The manufacturer believes that such a putty is quite enough and you can only get by with it.

For external and internal corners, we will use special paper-based corners from the same manufacturer Sheetrock.

Here is the outer corner with such a profile.

Here is the inside corner.

There is obviously less metal here, good perforation is noticeable at all corners. Perforation is necessary so that air bubbles come out, and also some amount of putty will come out through it. The corners themselves have a height of 3.05 meters, from which you can cut pieces of the desired size. Let's start with paper, show how to use it, apply it correctly, so that everything is competent and beautiful. The Knauf drywall itself is 12.5 mm thick, ordinary, not waterproof, GKL-PLUK 12.5X1200X2500.

If we immediately apply Sheetrock and try to stick a piece of paper, then a lot of putty will remain in the depth, no matter how we squeeze it out.

Gradually, the paper in this place will get wet and warp, increase in size and take on an unsightly appearance, creating difficulties for subsequent work.

Therefore, to work with these seams, it is better to use UNIFLOT. This is such a putty that sets very quickly, after 20–25 minutes it can already be sanded. First you need to putty the depth of the seam with UNIFLOT, go through with a spatula, and after 20 minutes you can put a piece of paper on Sheetrock here. All work will be completed in one day.

So, to work along the seam, you will need paper and a spatula of different widths.

With each subsequent layer of putty, you need to switch to the spatula of the next size. With a wide spatula, it will be possible to perform the final puttying of the seam.

We hammer UNIFLOT into the seam.

The sheet has a factory chamfer, very long, you don’t need to hammer all of it, since paper should still be located in this place. Therefore, we hammer only the very depth. You can take a narrow spatula with a width of, for example, 5 cm, and remove everything superfluous so that the putty remains only in the groove.

Now we will show how to reinforce the internal corners. We will use such a small comb spatula for this.

Such corners do not require any preparation. They have a metal part that Sheetrock will not stick to.

The metal will only reinforce the corner, and Sheetrock will be on the piece of paper itself. Therefore, if there are any gaps, they can not be sealed, but left as is. A gap of 3-4 mm wide is not at all scary, its preliminary sealing is not required. It is enough to make a few strokes of Sheetrock with light movements. It doesn't have to be pretty. The faster the better.

Then we carry out several times with a comb spatula.

Sheetrock is applied evenly, there are practically no empty spots. We take a corner, put it in its place, draw it with a spatula, squeeze out the excess from there.

If the corner is three meters, it is better to apply a little Sheetrock on the spatula. When we lead with a spatula, it will immediately level this piece of paper and create a small layer on top. A few movements - and the corner is reinforced.

Now you need to wait until it dries, take a larger spatula and putty the corner itself again. This is done easily, simply and quickly.

External corners are good because they do not require any preliminary puttying. Let's put some putty on. You don't need to level it hard.

We pass with a comb spatula. Now the corner is completely ready for installation.

We set the angle, orient it along the plane, press it on one side. You can put some sheetrock.

The putty is squeezed out from under the paper, the corners themselves are of high quality, the paper does not get wet, does not increase in size, and wrinkles do not form on it. If Sheetrock is under metal, it cannot have any effect on this metal and on paper. Therefore, here you can do the following. Do not wait for a long time, but immediately apply some more Sheetrock putty and remove it in one motion.

Leave the seam in this position until completely dry. Irregularities, dimples do not need to try to straighten immediately. One pass is enough, you still have to go 2-3 times to the outer and inner corners, and to the seams.

About half an hour has passed, UNIFLOT has dried up, there are no wet spots, nothing is scratched. Grinding with emery is not required, you can immediately apply paper. We take Sheetrock, fill the groove.

We take a piece of paper, put it with a curved place inside so that the tubercle does not stick out.

Squeeze out the entire Sheetrock slowly from there. On the spatula, you can apply a little putty for sliding.

You can move on to the next step. Since there is very little putty left under the paper, the paper will not get wet and warp. Remove excess putty from the edges immediately and leave to dry. Only after the Sheetrock is dry, you can proceed to the next steps.

Another 2-3 hours passed. Before completely puttying the entire wall, you need to go through this seam again with a wide spatula.

If there are small irregularities left, they will be covered by Sheetrock when we putty the entire wall. This is how it happens in reality with the full sizes of the corners:

We managed to work without any complicated devices, bazookas and other things, working on the “spatula technology”. This did not greatly affect the quality of work, in the end, everything can be compensated by experience.

All rights to the video belong to: Alexander Perikov

The expansion joint is an integral part and the most important event in the installation of concrete floors.

There are three main types of expansion joints:

1. insulating seams;
2. Shrink seams;
3. Structural seams.

Types of expansion joints

Seams are arranged along the walls, around the columns and around the foundations for equipment in order to exclude the transfer of deformations from the building structures to the floor screed.
An insulating joint is arranged by laying insulating material along the building structures immediately before pouring the concrete mix.

Shrink seams necessary in order to prevent chaotic cracking of the screed during the hardening process. They allow you to create straight slack planes in concrete. As a result, the screed gives a crack in a given direction.

Shrinkage joints should be cut along the axes of the columns, and join with the corners of the joints running along the perimeter of the columns.

Floor maps formed by shrinkage joints should be as square as possible. Stretched or L-shaped cards should be avoided. The length of the card should not exceed the width by more than 1.5 times. Shrink joints should be straight and, if possible, without branches.

In passages and driveways, shrinkage joints should be located at a distance equal to the width of the screed. Tracks wider than 300-360cm should have a longitudinal seam in the center. When concreting in open areas, the distance between the seams should not exceed 3 m in all directions. The general rule is that the smaller the map, the less chance of random cracking.

Cutting of shrinkage joints is carried out after the completion of the finishing treatment of the concrete surface.

Usually, the seams are cut with 6x6 m cards in the same sequence in which the concrete was laid. The seams should be cut to a depth of 1/3 of the thickness of the screed. This creates a slack zone in the screed, and during shrinkage, the concrete cracks in this zone, i.e. cracks directionally, not randomly. In this case, the edges of the formed crack have a certain roughness, which excludes their vertical displacement until the crack becomes too wide.

Construction seams are arranged where the day's work of laying concrete has been completed.

The shape of the edge of the screed for a structural joint is usually made according to the principle of a spike in a groove; sleepers (slats) laid across the joint can be used. The slats must be installed in the middle of the screed depth at right angles to the seam. One end of the rail must be lubricated with bitumen in order to move freely in the screed.

Structural joints work like shrink joints - they allow small horizontal movements, but not vertical ones. It is desirable that the structural seam coincide with the shrinkage one.

The device of the expansion joint should be carried out in strict accordance with the developed project. If there are any changes (for example, the size of the joint or the replacement of material), the design of the expansion joint must be agreed with representatives of the design organization.

Seam sealing

In the presence of wet processes in the room, the tightness of the joints is of particular importance, since the lack of tightness leads to peeling of organic coatings from the floor slab. This process is especially active at elevated temperatures in the premises.

In the course of work, the number and location of seams are set based not only on the coefficient of thermal expansion of materials, but also taking into account the shrinkage of concrete and possible deformations that most often occur in areas where the floor is mated with foundations for equipment, walls and columns.

Seam sealing protects the seam from water penetration and aggressive environments, as well as from clogging.
The type of sealant depends on the loads and operating conditions. For example, in many industrial and food plants, floors must be easy to clean and withstand high traffic loads.

Sealants for such floors must be hard enough to support the edges of the joint and prevent them from chipping, and ductile enough to withstand easy opening and closing of the joint.

Crack problem

Cracking in concrete can be reduced by reducing the amount of water used for mixing. But concrete, even with a low water content, shrinks, and besides, concrete made with fillers alone can shrink more than concrete with other fillers.

In view of the fact that it is impossible to eliminate the shrinkage of concrete made from traditional cements, the best solution is to allow the crack to appear in the place where its occurrence is desired and, moreover, in the form of a straight line. This is the expansion joint.

Seams can be made in freshly laid concrete with a special cutter. In dry concrete, the seams are sawn through. But even in screeds with cut or sawn expansion joints, cracks sometimes appear in other places. The likelihood of such cracks occurring can be reduced by doing the following:

cut the seams in time

By calling or writing to us, you can always get free samples of materials for trial application and consultation of our specialists.

If the seams are cut in freshly laid concrete, then time does not play a role. But if they are cut later, then random cracks are likely to appear. Joint cutting in freshly laid concrete is carried out immediately after surface grinding. On dry concrete, cutting joints should be done as quickly as possible so that the edges of the joints do not begin to crumble. It is usually recommended to do this after 12 hours at normal temperature, at low temperature - 24 hours after the concrete has been laid.

Cut the seams to the required depth
Seams cut with conventional seam cutters should have a depth of 1/4 to 1/3 of the thickness of the screed. Seams made by special cutters on fresh concrete may have a shallower depth.

Cut seams at the required spacing
Usually, the interval for cutting seams is chosen within (24-36) x (screed thickness). On a 10 cm screed, the seams are cut at a distance of 240 cm to 360 cm from each other. For concrete with greater slump and shrinkage, it is preferable to have a cutting interval closer to 240cm.

Exclude interior corners
Cracks are more likely to appear at inner corners. The grid of seams should be such as to exclude the formation of internal corners.

Eliminate T-shaped intersection of seams
The T-shaped intersection of the seams leads to the formation of a crack passing through the crossed seam. When planning a grid of seams, T-shaped intersections should be avoided.

The areas bounded by the seams should have a shape close to a square

If the length of the section is 1.5 times the width, then the crack will most likely appear in the middle of the long side. The seam pattern should be such as to avoid the formation of long and narrow sections.

Eliminate the formation of triangular areas with sharp corners
Triangular areas with sharp corners usually crack at the end of the sharp corner. In general, triangles should be avoided, however, if required, the seams should form an equilateral triangle.

Sometimes cracks form in concrete that has not gained strength. These shrinkage cracks usually occur during dry, hot and windy weather. If such weather conditions are expected during the laying of concrete, then concrete with synthetic fibers should be used, and during the laying and grouting of concrete, moisten its surface with water.