Repair Design Furniture

Lags on a concrete floor: how to fix them (with anchors, self-tapping screws, corners), put them correctly? Do-it-yourself fence from a professional sheet: a step-by-step photo report How to fix veins to metal posts

The fence performs not only a protective function - it is also a kind of "visiting card" of the owner of the site. It is by his appearance that passers-by judge the level of wealth of the owners, their taste and even character. This means that the fence must be given no less attention than the house and outbuildings. What should be the fence? Of course, durable, unpretentious and attractive. It is also desirable that its installation be as cheap as possible.

All these requirements are met by fences from a profile sheet on concrete pillars. Judge for yourself! The corrugated board is not afraid of either frost or hot sun. It has good soundproofing and windproof qualities, and can make your site more comfortable. It is a strong and durable material, since its service life is not less than twenty years. And concrete supports are durable, durable and inexpensive.

Construction methods

There are two options for building a fence from a profile sheet on concrete pillars. Ready-made supports can be purchased. In this case, time is saved, but you cannot be sure of the quality of concrete, you will have to be content with pillars of standard shapes and sizes. In addition, the problem of fixing the corrugated board to a completely smooth concrete post will inevitably arise.

Or you can cast the supports yourself, spending some time on this, but be sure of their strength in the future, be able to create exclusive pillars, and, in addition, solve the problem of embedded elements, to which the lags will be attached in the future.

If you choose the second option, we start building the fence, breaking it down into several stages.

Frame material

It is possible to create a column with its subsequent installation in the ground or monolithic casting, in which the support is made directly at the installation site. To create a pillar in the first way, you first need to make a formwork. The material can be:

  • a wooden box of appropriate dimensions (for a square post). The inner surface of the box is upholstered with plastic and closed with polyethylene;
  • a metal pipe cut along the length, tightened with clamps (for round supports). The inside of the pipe must be coated with diesel fuel or mining so that the concrete does not stick to the metal.

In addition, keep in mind that concrete, for all its advantages, does not differ in fracture strength. Therefore, to eliminate this disadvantage, you will need fittings.

Two manufacturing technologies

If the post has a section of 10x10 cm, then four rods with a diameter of 1 cm and a wire 0.8 cm thick are enough to tie or weld them, creating a reinforcing cage.

The dimensions of the frame must be such that it is surrounded on all sides by a layer of concrete with a thickness of at least 2 cm, otherwise moisture will quickly destroy the reinforcement, and after it, the post itself.
For the concrete mixture, fine gravel and sand are used - 3 parts, cement - 1 part, water - 20% of the volume of solid components, various dyes and additives that accelerate the setting of concrete, hydrophobic, increase frost resistance and other additives.

The first way

First, a layer of concrete 2 cm thick is poured into the formwork. Then the reinforcement cage is installed and the mold is poured to the top. The concrete mix must be vibrated to avoid the formation of cavities that weaken the structure. After the concrete hardens, the formwork is disassembled, so it is better to do it with screws.

Do not forget about the mortgages, to which the logs will subsequently be attached! They should protrude about 15 cm beyond the pillar, so it will be necessary to make slots in the formwork in the right places, and weld the metal plates themselves to the reinforcement, having previously determined their location.

Second way

The process of monolithic casting is similar to that described above, with the difference that in this case a hole is made in the soil, a layer of crushed stone 2 cm thick is poured into it. Further, the frame is installed and poured with concrete.

After it grabs, the formwork is placed, and the post is concreted in several stages, the mixture is compacted each time by vibration or bayonetting.

Before installing the pre-cast posts, or when drilling holes for monolithic casting, carefully mark the area and determine the position of the corner posts. Pull the twine between them and mark the places for the rest of the supports.

Cast pillars are installed in prepared holes, on a sand or crushed stone cushion, fixed with wedges and concreted in layers with compaction of each of the layers.

When using sheets of corrugated board, the distance between them is considered optimal - 2.5 meters. Do not forget to mark where the gate and / or gate will be.

Consider a few nuances

A fence made of corrugated board is a solid structure, which means that it will experience large wind loads, so the depth of the hole should be about 2/3 of the height of the fence (for example, with a fence height of 180 cm, a hole 120 cm deep is needed).

Concrete supports are quite heavy, and at the slightest deviation from the vertical during installation, they will roll further themselves in the future. Carefully check their verticality using a level or plumb line.

With wet soils and a large force of frost heaving, the supports need additional reinforcement, therefore, in this case, the hole is made with an extension in the lower part (with monolithic casting) or a concrete base is created with a diameter larger than the pillar (if the pillars were cast in advance).
Using a plumb line and twine stretched over the corner posts, make sure that the height of all supports is the same, otherwise it will be difficult to avoid distortions in the future.

When the concrete sets, the upper parts of the supports must be protected from rain and other adverse factors with special caps. Please note that the diameter of the caps must be about 10 cm larger than the diameter of the post. If the supports are already installed, proceed to the next step.

We weld the lags

First, it is necessary to fix (weld) on the embedded joists - a steel transverse profile, on which the profile sheet will be attached in the future. For them, you can take a metal pipe with a cross section of 25 - 40 mm (a pipe of a smaller diameter may not withstand the weight of metal sheets).

The number of lags depends on the height of the fence: if it is not more than 1.8 meters, then two lags are quite enough, with a higher height it is better to use three lags. Keep in mind that the top log is attached at a distance of 30 cm from the top of the posts. The lower one is at a distance of 30 cm from the ground. And the middle (if needed) is in the middle.
In advance, even at the stage of casting concrete pillars, decide on the height of the fence and, in accordance with this parameter, find the attachment points for the mortgages, then you will not have any problems with installing the lag!

After the lags are welded, the welding places must be cleaned, primed and painted all metal parts. And finally, the last stage.

The choice of corrugated board

First, a few words about this material: after all, the appearance of your fence will depend on it.

First, you need a wall sheeting designed specifically for these purposes, not roofing.

Secondly, when choosing it, pay attention not only to color, but also to quality. There are the following types of wall sheeting:

  1. C-8. The leader of sales due to the low price.
  2. S-10. It will be stronger and tougher, moreover, it has a more attractive appearance.
  3. S-14. The best option if there is a high probability of any mechanical damage for your fence.
  4. S-15. A sheet with a wide edge, which will give your fence originality.
  5. S-18 and S-20. The strongest and toughest sheets used for tall fences.

Also consider the thickness of the profile. For a wall sheet, this parameter should be at least 0.4 mm (preferably 0.45 mm). Thinner sheets can only be used to create temporary fences.

The type of coverage is no less important. Remember that zinc coating (the sheet will be metallic), although the cheapest, but short-lived. The polymer coating, when a synthetic resin is applied to the zinc layer, increases the sheet's resistance to aggressive factors and lengthens its service life. Plastisol is the most reliable, but also the most expensive coating.
Be sure to check that the sheets are even, without scratches, and evenly painted over. When purchasing, make sure that the packaging film is intact.

Fastening the sheathing to the joists

The sheets are overlapped and attached to the logs with self-tapping screws 3.5 cm long with an interval of 50 cm. Try to get screws of the same color as the fence - the structure will look better.

Be sure to use gloves when working with this material, otherwise cuts and scratches cannot be avoided. Stock up in advance with a can of paint of the same color as the corrugated board in case of scratches that may occur during installation and during operation.

It is recommended to install sheets in a protective PET film: it will protect the sheet from most damage. But immediately after installation, the film should be removed, otherwise, under the influence of UV rays, it will firmly adhere to the metal, and it will be problematic to remove it in the future.

Over time, the polyethylene will lose its transparency, in places it will tear, hanging in shreds, and will give your otherwise perfect fence an untidy look.

It will be about a simple fence made of C8 corrugated board without any frills: pillars 3m 60x60, 3-meter spans, logs 40x20, two-meter corrugated board 0.4mm.
Upon request on the Internet, you will immediately find two main ways of attaching the logs (veins) to the fence posts: welding and various brackets (now it is fashionable to call the X-bracket). In my case: welding, due to absence, disappeared. Brackets - in my opinion, an extra waste of money. In fact - why be wise - two flat surfaces: a 60x60 post and a 40x20 lag - attach them to each other and fasten them together: even with a bolt, even with a self-tapping screw ...

I'm not the only one that smart - there are similar tips on the Internet. Recommended bolt М8х90 with nut. In this way, I was worried about the protruding head of the bolt - what if the wave of the profiled sheet does not fall on it? ...

As a result, I took M6x90 countersunk screws. With a drill with a diameter of 6.5 mm, the outer hole in the vein when drilling a log and a pillar just breaks to a suitable size. And the screw head does not fall through, and such a design does not protrude high.
It is better to tighten the nut with a washer and a spring washer, but ... the length of the 90 mm screw was not enough to install the spring washer - we had to do without it.
The shear and rupture strength of M6 screws is one and a half times worse than that of M8, but the "plates" show that even in the worst case, when choosing a lousy screw material, the safety margin should be enough. In my case, a 6m long section of the fence (about 60-70 kg) is supported by three posts (six M6 screws).

Not so long ago, in the process of laying the logs, pieces of plywood or wooden stakes were laid on the rough base under the beams. Thus, it was possible to protect the tree from moisture and level the rough base horizontally. But over time, the substrate dried out and fell into disrepair, which affected the horizontality of the coating. In the article we will consider modern ways of attaching lags to various types of bases.

Features of the use of fasteners


In the process of attaching the lag to a wooden base, there are no special problems. To do this, you can use long screws or corners. But what about the concrete base, into which you cannot easily screw self-tapping screws? To strengthen the joists on concrete, you need to use special types of fasteners. The choice of fasteners required for mounting the beams to the concrete floor depends on the following factors:

  1. The horizontalness of the surface. Depending on whether additional alignment is required or not, height-adjustable or non-height-adjustable fasteners can be used;
  2. The moisture level of the substrate. If the logs are mounted on a strip foundation, they will have to be laid almost on the ground. To fix the beams, they mainly use brick posts that protect the tree from moisture, playing the role of an insulating lining;
  3. The degree of load on the base. You can strengthen the joists on the floor with the help of self-tapping screws and brackets. However, in the case of intensive use of the floor, the self-tapping screws may not withstand the load. That is why the type of fastener is chosen in accordance with the expected load on the floor covering;
  4. The heights of the underground. Wood floors are prone to condensation underneath and rot. To protect the wooden base from decay and deformation, experts recommend using high supports for the logs. They form an underground space under the beams, in which air can circulate freely, which prevents the formation of condensation.

To properly fix the beams to the subfloor, you need to understand not only the fastening methods, but also the types of fasteners. Adequate choice of support will extend the service life of not only the rough, but also the finishing coat.

Types of fasteners


As already noted, fastening the beams to the floor involves the use of only two types of fasteners:

  • Simple - static supports that do not allow varying the installation height of wooden elements;
  • Adjustable - contain a screw structure, thanks to which the fasteners can be adjusted in height, which allows you to achieve maximum horizontal base.

What types of fasteners can be used to secure the planks to the floor?

  • support posts;
  • self-tapping screws;
  • corners;
  • brackets;
  • anchor.

To understand the essence and features of the use of the above details, we will consider each of the categories in more detail.

Self-tapping screws


Self-tapping screws are simple fasteners that are used to finish wood, but not concrete, floors. Long enough male threaded rods are capable of attaching beams to wooden floors, but only if the following nuances are taken into account:

  • Before the fasteners, both in the beams themselves and at the base, through holes must be made;
  • It is necessary to insert a dowel into the through hole and only then screw in the self-tapping screw;
  • So that the lags do not come off the wooden base, the screws are fixed in increments of 40-60 mm;
  • The length of the screw is determined by the thickness of the beams, it is desirable that in the process of screwing in, the "tail" of the screw goes into the base by at least 5 cm.

The affordable price of fasteners has made them very popular among DIYers. But in order to achieve the desired result, in the process of installing the lag, it is imperative to take into account the above points.

Anchor


Anchor is a combined fastener with self-fastening, which, unlike dowels, is not only easily fixed in the base, but also supports the weight of heavy structures. The anchor is one of the most durable and reliable types of fasteners that are used to attach the lag to any foundation (tape, pile). If we discard all the "sentiment", the anchor is still the same dowel, but with a more powerful base.

In the process of fastening, the lag anchor is mounted in about the same way as a self-tapping screw:

  1. Through holes are made in the bars, after which symmetrical, but not through holes are made in the base;
  2. To mask the head of the bolt, the bars must first be cross-drilled;
  3. Since the anchor is very strong and capable of supporting heavy structures, no more than 4 fasteners are required to fasten one bar;
  4. The locking parts of the anchors are inserted into the holes obtained, through which the bolts are screwed;
  5. When sewing the log through, it is necessary that the bolts go deep into the base by about 6 cm.

To strengthen the beams on a rough basis, experts recommend using anchors with a diameter of 8 to 10 mm. Metal rods of this thickness can easily withstand very heavy loads.

Brackets

Brackets - cantilever supports that serve as a static base for fastening parts in a vertical plane. As a rule, they are used in the process of attaching the lag to the support pillars. The cruciform (x-shaped) curved parts have fixed flaps into which the timber is laid. The price of such products is much higher than in the case of self-tapping screws, however, the range of possibilities for such fasteners is much greater.

Very often, in the process of laying the subfloor, brick posts are installed on the strip foundation. They act as supports and protect the tree from moisture. Since the lag is punched out over time, it can deform without additional fasteners. The only convenient and reliable way to fix the beams to the supports is to use brackets.

Support posts


Bollards for logs are supporting structures that are assembled from bricks with a section of 1-2 bricks. In fact, these elements perform the task of "invisible" lining, preventing the effect of dampness on the wood. The posts are mounted in the case of laying a rough base on a strip foundation or concrete. Since the water table can constantly change in order to protect the logs from water, they deliberately form an underground.

In order to properly strengthen the logs and erect the posts, you should take into account the following points:

  1. It is undesirable to build supports from hygroscopic materials - artificial stone or silicate bricks;
  2. Do not install posts on loose soils that can be washed out by water;
  3. Supports that will be installed on non-flowing soil must be made above the soil level underground by at least 2-3 rows of masonry;
  4. It is advisable to lay the pillars with a single-row dressing, observing a single height level for all supports;
  5. You can fasten the beams to the supports using brackets, anchors or special corners with self-tapping screws for concrete.

Corners


Corners are galvanized metal parts with two planes orthogonal to each other. The price of such fasteners is largely determined by the size of the elements themselves, as well as their thickness. The degree of strength of the corners directly depends on the above parameters. In the process of fixing the lag, it is advisable to pay attention to such nuances.

Any owner of a suburban area quite rightly tries to fence off his possessions in some way. Thus, the construction of a fence is always included in the list of priority tasks, and it is often started to be installed even before the start of the construction of the main house. There are a great many design options for such fences. But despite the very wide range of materials offered for sale, both general construction and specially designed for the construction of fences, wooden fences remain one of the most popular.

Wooden fences have been used since time immemorial and have proven to be practical. True, the fence supports were and remain a weak spot - the wood from constant contact with the ground quickly lends itself to biodegradation, and the age of wooden posts, alas, is short-lived. But nothing in our time prevents us from finding a more solid solution. So, for example, a wooden fence on metal poles will last much longer . It is about such fences that will be discussed in this publication.

Wooden logs are absolutely necessary to ensure natural ventilation of the underground space and better preserve heat in the premises. Thanks to the use of logs, the flooring will be able to last much longer. However, among people who do not have much experience in the construction business, you can often hear the question, is it necessary to fasten the joists to the concrete floor? Experienced craftsmen know that for a truly durable flooring that does not change its geometry under load, and for its long service, it is imperative to correctly fix the logs on any supporting structure, including on a concrete screed.

Now, when it is clear whether it is necessary to fasten the logs to the concrete floor, it is worth noting that this task is simple, does not require special skills and knowledge, and, therefore, any home craftsman can handle it.

  • Materials and tools
    • Fasteners
    • Tips for choosing a lag
    • Instruments
  • Methods for mounting a lag on a concrete floor
    • Fastening the lag to a metal corner
    • Fastening the lag to concrete pillars
  • DIY step-by-step instructions for attaching the lag to concrete
  • Step between lags

Materials and tools

Fasteners

The question of how to fix the joists to a concrete floor has different answers: simple or adjustable structures can be used for this. In the latter, special screws are used, by tightening which, the lags can be leveled. In addition, the choice of fasteners and fastening methods depends on which joists are used.

Most often, the lag is fastened to the concrete floor with metal anchors or self-tapping screws with polypropylene dowels, the dimensions of which are selected depending on the section of the selected timber for the lag.

The choice between anchor nails or self-tapping screws is due to the following:

  • Self-tapping screws are cheaper, of course, but anchors are more reliable. In practice, fastening with self-tapping screws is almost always sufficient.
  • The advantage of anchors is that, in addition to fixing the beams, they tightly press the logs to the base. This becomes especially important when the topcoat is heavy enough and is regularly exposed to mechanical stress - this must be taken into account when choosing the method of how to properly attach the logs to the concrete floor.

With modern technologies, logs under a wooden floor could not have been fixed at all, however, such a solution would greatly increase the likelihood of skewing the floor covering or displacement of the log from its original place. Therefore, with regard to fixing the lag, it is best to rely on old methods that have been proven more than once by time.

However, the fastening may not help if low-quality or unsuitable sawn timber or incorrect fasteners are selected for work.

When joists are selected on a concrete floor, you need to pay attention to the following points:

  • type of wood;
  • lumber grade;
  • length and section;
  • price.

For reasons of economic feasibility, you should not take expensive wood, because spruce, fir or pine, if properly processed, can last no less. The appearance of the material does not really matter, however, it is necessary to sweep away specimens eaten by grinders or blackened from mold. The evenness of tone and the correctness of the geometry of the lag are of less importance. For this work, grades B and BC with a moisture content of no higher than 20% are suitable. As it is customary to work with lumber, they should be stored for some time in a dry room so that they equalize in humidity with the surrounding atmosphere.

All wooden elements must be thoroughly impregnated with an antiseptic before attaching the logs to the concrete floor.

Instruments

Since the task is how to lay the logs on the concrete floor, then in the work you will have to use the following tools:

  • Drill and hammer drill.
  • Carpentry tools: circular saw, hacksaw, plane.

In addition, you will have to spend money on waterproofing, which must be spread over the entire surface of the concrete. When calculating the amount of material, you need to add more overlaps of 10-15 cm to the floor area.

Methods for mounting a lag on a concrete floor

The methods of attaching the lag to the concrete floor are reduced to four main options, having familiarized themselves with which, any master can choose the most suitable one for himself.

This is the simplest way to attach a lag, but, unfortunately, it does not work in every situation.

  1. First, you need to drill holes in the timber for the diameter of the plastic dowel, and make a reciprocal hole in the concrete with a puncher.
  2. Then the dowels are hammered in with a hammer, after which self-tapping screws are screwed into them or dowel-nails are driven into the floor.
  3. At the same time, the screw head should sink a few centimeters into the hole.

It is often asked which step of fastening the log to the concrete floor is better to choose? There is no rigid standard here - the step can vary from 40 cm to 80 cm, on average, you can safely focus on half a meter.

Reliably enough, the lags will only hold when there is a small gap between the base and the timber. This must be taken into account by those who want to know how to properly lay logs on a concrete floor.

Anchors, unlike self-tapping screws, not only firmly fix the logs, but also attract them to the concrete surface. Thanks to this installation, wooden beams will hold more reliably, so most craftsmen prefer to use anchors. In addition, this powerful fastener will restrain the deformation of the tree to a certain extent, especially if it has not been sufficiently dried beforehand. But pulling the anchor out of the concrete base is much more difficult than driving it in there, so workers will have to spend a lot of effort during dismantling.

Be that as it may, but when using anchors, the floor covering will not swell, but it can bend. To avoid the latter, it is necessary to install gaskets more often.

  1. The installation of the log on the concrete floor here begins with drilling through holes in the timber.
  2. Then, opposite each of them, counter holes are made in the concrete.
  3. After that, the anchor bolt is inserted into both holes and tightened with a box or open-end wrench. In this case, it is important not to overtighten the bolt, otherwise it will bend the beam, especially when there is a gap in this place. Then there will be a deepening in the finishing field.

Before installing the anchor in the beam, you need to drill a recess with a larger diameter so that the head of the bolt fits there.

The anchors should be spaced 60-100 cm apart, and they should be long enough to penetrate the concrete by about 6 cm. Anchors with a diameter of 10 mm are most often used. Usually one lag is held by 4-5 anchors.

Video about fixing the lag to the concrete floor with anchors:

Fastening the lag to a metal corner

It becomes inconvenient to work with lags with a height of 10 centimeters or more. To fasten them, it is better to use steel corners, which with one shelf will be in contact with the log, and the other with the concrete base. Fixation in this case is made: to concrete - with dowel-nails, and to the timber - with self-tapping screws. In this case, the main load should fall on the gaskets, and not on the fasteners, because the corners should only fix the position of the beam.

In order for the lag to be better fastened to the surface, you need to use self-tapping screws, in which the thread does not reach the cap.

You can also fasten wooden elements to a concrete base using a galvanized steel corner. The installation process is as follows:

  1. Attach the corner to the log by means of self-tapping screws, which should go deep into the wood by at least 30 mm.
  2. Attach the corner to the concrete base with dowels.

Video on how to fix the logs to the concrete floor with corners:

There is another option, how to fix the logs to the concrete floor. For this, a rectangular stand is used, which is attracted to the base with four dowels. In the middle of this support there is a hairpin that penetrates the beam through and through.

By rotating the nut under the beam, you can set its height quite accurately, and with the help of the upper nut fix the element in the required position.

This system is not so difficult to install, it is attached to the floor with dowels, and in the log you will need to make a hole for the hairpin. The frequency of mounting the stands under it depends on the section of the log, however, in any case, it is not recommended to make an interval of more than 1 meter. A similar option for attaching a lag to a concrete base, although recognized as optimal, however, due to its high cost, did not become very popular.

After fixing the lags, a rough floor is laid on them from boards, OSB or similar materials. If the work is done well, then the appearance of the finished floor can be flawless.

Fastening the lag to concrete pillars

Lags are similarly attached to concrete pillars. Here, the same fasteners are used, but intended for pillars.

  1. In advance, the pillars need to be waterproofed by coating them with simple bitumen or bitumen mastic. The upper cut of the pillars can be waterproofed by putting pieces of roofing material pre-cut according to its configuration on it.
  2. Also, in advance, holes must be made into the bases of the posts and in the timber, into which a dowel or anchor strut must be driven.
  3. The beam is attracted to the post with a self-tapping screw, in which the length is 2-3 times the width of the spacer.
  4. Also, the beam can be attached with special metal plates equipped with screws. To this end, they are screwed to the base of the posts with dowel-nails, and a through hole is drilled in the lag, into which you will then need to insert a screw and screw the lag to the top of the posts. Thanks to this, the lag will hold on tightly.

DIY step-by-step instructions for attaching the lag to concrete

It is not difficult to attach wooden logs to the concrete floor, even alone. There are several fastening options, and below are the steps of one of the standard methods.

  1. Lay waterproofing (roofing felt or a simple PVC film) on the concrete base. The joints between the pieces must be fixed with special tape.

  1. Next, you need to spread the logs along the floor with a certain step. This step will depend on the material from which the finishing flooring will be made: when using a sheet pile board of 25x100 mm, logs can be laid with an indent of 70-80 cm, and for other materials, the step will need to be reduced to 40 cm.
  2. If the length of the material is not enough to cover the entire room, then it is permissible to join the elements using an iron corner or by making cuts that form a connection into a root spike.
  3. Before installing the logs on the concrete floor, you need to tackle the extreme logs that will be near the walls. They must be laid on a level, clearly leveling their height by placing wooden planks or pieces of plywood under the beams. The most convenient way is to use a laser level. When the extreme logs are fixed, a nylon thread is pulled between them, which will be a guide when installing the rest of the logs.
  4. To attach a timber to the concrete floor, you need to make holes in both. A dowel or steel anchor spacer must be driven into the hole in the concrete. Each lag must be fixed with at least four anchors, and the screws must be placed 40-60 cm apart.

  1. It is necessary to prepare in advance levelers for the lag - cut chipboard or plywood into even strips. With the help of these elements, the lag structure is fixed in an even position (pieces of plywood are simply placed under the lags, if you need to raise them) so that the finish coating on it does not creak or walk.

  1. If, on the contrary, there are bulges in the concrete base, then the lag will have to be leveled not by laying plywood, but by choosing part of the material from below with the help of a planer.
  2. When all the logs are installed in their places, then thermal insulation should be laid between them, for example, covered with expanded clay.

  1. Before closing with a topcoat, you should think about laying the necessary communications. It is also advisable to use a vapor barrier layer.

Step between lags

How to properly lay the joists on the concrete floor if different materials will be used for the topcoat? Below is the relationship between the thickness of the floorboards and the distance between the joists:

  • with a board thickness of 20 mm, there should be a distance of 20 cm between the lags;
  • for boards with a thickness of 25 mm, a step of 50 cm is required;
  • for 25 mm - 60 cm;
  • for 40 mm - 70 cm;
  • for 45 mm - 80 cm;
  • for 50 mm - 100 cm.

If the floor is plywood, then the step between the lags is determined differently:

  • with a plywood thickness of 15-18 mm, a lag step of 40 cm is required;
  • at 22 mm - 60 cm.

In what way do you prefer to fix the joists to the concrete floor, and why? Share your opinion or experience in the comments.