Basic and most common connections in a frame house easier and more reliable to perform using special fasteners. Each of them has its own fasteners, ensuring the strength and stability of the entire structure. It is easy to use and allows you to avoid such labor-intensive connections as inserting “half-wood” or various “locks”.
Connecting fasteners for assembling frame wooden building structures has been used for a long time: tightening brackets, bolts and clamps. Very often used in construction frame houses. Today it has become more diverse and perfect. Fasteners not only simplify and speed up the assembly of building structures, but also make them stronger and more stable. Fasteners are most effectively used in the construction of prefabricated frame houses. Connecting fasteners for assembling construction wooden structures too diverse to be described in one article. Therefore, using the example frame house We will consider only part of the fasteners, but the most used and mass-produced.
Connection fastener made from cold-rolled steel sheet with a thickness of 2.0 - 4.0 mm, in the form of perforated (with holes) plates, corners, holders, supports for beams, connectors (plates with needle spikes - connectors), as well as shoes for load-bearing posts and columns , mounted directly on the foundation. Depending on the purpose (the dimensions of the parts to be connected and the loads transferred to them), each type of such fastener is presented in several versions: by size, perforation configuration (holes) and even with additional elements(ribs) of increased rigidity.
The perforation of the fasteners regulates the thickness of the nails and tightening bolts, as well as their number: on the one hand, they are enough to securely fix the connection, on the other hand, cracking of the wood does not occur. Such fasteners may have various coatings, protecting it from corrosion: zinc, primer or polymer powder paint. Part of the connecting fasteners is also used for repair work(for example, a corner when constructing a frame internal partitions). Therefore, when choosing such fasteners (standard sizes, metal thickness, design option, perforation, stiffeners and protective covering), you should imagine what loads it will experience during operation.
Connecting fasteners have a number of undeniable advantages over classical connections in the construction of low-rise buildings. wooden houses and, first of all, prefabricated frame ones, in which a lot of different nodal connections have to be made.
Firstly, there is no need to make labor-intensive and skill-requiring classical connections such as half-timber inserts or tie-locks. There is no splitting of wooden structures due to excessive large quantity and sizes of nails and bolts: the normalized perforation of fasteners (holes) does not allow the use of too thick nails and driving them close to the edge of the bar.
Secondly, the classic tie-in leads to a decrease in the strength of the beam due to a reduction in its cross-section at the joints (wood removal). Steel connecting fastener, on the contrary, creates additional reinforcement of the design of the nodes.
: Used in butt joints that are subject to tensile loads, such as splicing timber for tightening or making roof trusses.
Fastening plates are used in connections subject to tensile loads. They are applied to the connection on both sides and tightened: with bolts - 2 holes with a diameter of 11 mm and nails - the remaining holes with a diameter of 7.5, 5 and 4.5 mm. The dimensions of the holes determine the diameter of the bolts and nails used: their task is to provide the necessary strength of the connection, preventing splitting of the wood.
: used in various corner connections(walls, racks with a supporting frame, tie beams, roof rafters, etc.). An angle with a stiffener has a higher resistance to bending loads.
Fastening angles are used for angular connections between walls or an upper tie beam with a roof truss. Available in various standard sizes and several designs, including those reinforced with a stiffener. The corners are applied to the joint on both sides and tightened: with bolts - 2 holes with a diameter of 11 mm and nails - the remaining holes with a diameter of 7.5, 5 and 4.5 mm. Bolts for fixation are used only in particularly strong connections.
Installation of beams attic floor or roof rafters using mounting angles. Perforation of fasteners ensures the optimal number, thickness and location of nails in terms of the loads occurring in the joint and eliminates splitting of wood. Corners with a stiffener are more resistant to bending loads.
Beam holders and supports
Beam holders and supports: indispensable for constructing floors (floors and attics) in frame houses. Withstands high tensile loads in various corner joints. The holder is designed for fixing a floor beam to a wall, column or other beam during construction. The support (or shoe) allows you to install the beam on the walls or columns of an already erected building (during reconstruction).
The support can be universal (consists of separate left-handed and right-handed elements) - suitable for beams of any section, and specialized - for beams of a specific section. In addition, the support can be designed for open mounting or for finishing. Shoes for posts and columns: The shoe is bolted or poured with concrete into the foundation or foundation. Its design allows, even after installation, to adjust its height (± 25 mm).
The beam holder is used when installing wooden floors when it lies with its ends on walls or other beams. Each connection is fixed on both sides. Therefore, the holder can be left-handed or right-handed. It is nailed down. The number and size of nails are regulated by holes with a diameter of 5 mm.
Consists of two individual parts- left-handed and right-handed and suitable for beams of various sections. The connection is fixed on both sides with bolts and nails. Mostly such supports are produced in one standard size and from sheet steel with a thickness of at least 2.5 cm.
It is designed for a specific beam section and is available in several standard sizes and two design options: 1 and 3 - for subsequent finishing in order to hide their vertical “wings” curved outward for fasteners; 2 - without subsequent finishing (“wings” are hidden).
Beam support is used when constructing wooden floors, when it cannot be supported on the walls or columns themselves (for example, installing a floor in an existing building). Each connection is fixed on both sides with bolts and nails. In our example, two short beams are connected by supports through a central post - practical solution a frequently occurring problem.
Shoes for load-bearing posts and columns are installed (anchored) in concrete foundation during its pouring (and bolted to the finished one). Exist various designs shoes: 1 and 4 - for pouring in concrete; 2 and 3 - fastened with bolts; 1 and 2 - the rack is installed in the shoe; 3 and 4 - the shoe is cut into the rack; All structures, once mounted, can be rotated around their own axis and adjusted in height.
The rack or column is installed on the mounted shoe and fixed required quantity bolts: 1 - the rack is installed in the shoe; 2 - the shoe is cut into the rack. In this state, the stand can be rotated to the desired angle around the axis and adjusted in height within a range of ± 25 mm.
Connectors
Connectors: designed for complex joint connections in roof trusses spanning spans of 7.5 meters or more. The connector is a flat plate, in the body of which needle nails (or spikes) of a certain configuration are cut out by stamping. They are made both in the form of plates with specific dimensions, and as a tape (25 - 152 mm wide), cut to the required length. The connectors are pressed with spikes into the wood (across the grain) on both sides of the connection. The principle of working with connectors is well understood using the example of installing a roof truss, where two connectors (on 2 sides) allow you to assemble an assembly from 3 parts at once.
Connectors - special connecting fasteners
Connectors are special connecting fasteners. It allows you to assemble and strengthen complex joint connections of 3 or more parts, for example, in roof trusses with spans of more than 7.5 m. The connector is a flat plate with needle-shaped spikes cut into its body. They are made in the form of ready-made plates with specific dimensions or tapes (25 - 152 mm wide). They are pressed with tenons into the wood on both sides of the joint.
When creating a modern frame structure, they use self-tapping screws, nails or screws. This is enough convenient option fasteners And in ancient times, such wooden structures were created without a single nail or screw. The craftsmen knew how to create a hidden tongue and groove. This mount was very strong. Created several centuries ago, Western European half-timbered houses they still live today, because the tenon and groove that the carpenters of that time used is a skill without which it was impossible to build frame house. Most likely, nails and various staples already existed, but they were not used at that time due to their extremely high cost. The tongue-and-groove fastening is largely justified because it connects wood to wood, and this is considered more expedient than fastening wood to wood with self-tapping screws or nails. And yet, today self-tapping screws and nails are a popular type of hardware, and craftsmen who have mastered the skill of making precise and reliable type“Slant tooth” and “dovetail” are almost non-existent today. Although such alternative connections are quite acceptable and even preferable in our time.
Strength frame structure and its rigidity depends not only on the quality of the connections and the quality of the material used itself, but also on the method of fastening and well-distributed loads at the design stage. If the connections are made incorrectly or overloaded, they will soon manifest themselves with singing sounds and creaks. To prevent the structure from becoming loose, you must strictly follow the assembly technology and monitor the quality of assembly of the frame elements. To prevent self-tapping screws from corroding, they must be galvanized or otherwise treated against corrosion. You can additionally dip them in drying oil, primer or some other protective composition during screwing or process well after, although this will be less effective.
In fact, nails are successfully replaced with self-tapping screws various types. Because they have a number of advantages. The main advantage is that they securely fasten all the elements. Unlike a nail, a self-tapping screw has a thread. This allows it to be screwed into any materials: be it wood, plastic, drywall, plywood or metal. For metal use special screws, with stronger structure and smaller threads. In addition, self-tapping screws, with the same length as a nail, have increased strength in terms of tensile strength. Even a small self-tapping screw will hold any material firmly, and most likely will not loosen over time, as can happen with a nail when assembling furniture. This allows you to successfully use self-tapping screws where nails can damage appearance. And what’s also important is that the self-tapping screws can be easily removed if necessary, since they have threads and a slot for unscrewing.
A few tips and tricks for using self-tapping screws and nails in construction
The number of nails used does not guarantee the strength of the structure.
You need to place nails “wisely”. It is advisable not to hit them at the edge of the board so as not to split them. It is better to hammer nails at an angle - this way they hold more securely.
If you need to hammer a nail into a certain place, but there is a risk of splitting the board, first blunt the point; the nail will not push the fibers apart and split the board, but will crush them.
It is advisable to select the length of the nail so that it does not protrude slightly from the material to which we are nailing. A nail that is too thin will not hold well. Long - it takes a long time to score, and it won’t be stronger if it comes out or splits the board.
Where the structure “works to be pulled off,” it is better to use self-tapping screws of the required diameter instead of nails. It's more reliable.
Self-tapping screws are also preferable where any vibrations are transmitted to the structure, for example: doors, windows; and also where we carry out wood paneling with any other material: fiberboard, fiberboard, plywood, plastic, etc., as well as when attaching to wooden structures, for example: metal wire hangers, flagpoles, etc. In such places, the nails “come out” over time, and you have to finish them off, which does not add strength. It is better to immediately replace such a “live” nail with a self-tapping screw or screw.
Self-tapping screws are also used in those places that will probably have to be disassembled later; this will make disassembly easier and will not damage the material being disassembled.
To prevent the self-tapping screw from splitting the wood when screwing, you can pre-drill a hole of the same or smaller diameter.
It is much easier to tighten the self-tapping screw if you lubricate it with soap or dip it in oil.
A drill with a bit or screwdriver installed in its chuck will help you quickly tighten many self-tapping screws. If possible, use a special screwdriver. It will, of course, be more convenient for them to work. In this case, the assembly speed on self-tapping screws will be the same as on nails.
In chapter, Download documents, instructions, programs There is a document: Connections with nails, screws and screws. Selection of fasteners for wooden house construction, requirements and test methods.
The standard was prepared by the Association wooden house construction within the framework of the adopted program “General program of work on regulatory and technical support for the production and use of wooden structures.” A very detailed document with explanations: what fasteners to use and where, their type and size.
And now another fact: what happened to the screws in just a few rainy days.
In the summer of 2013, the porch of my house was painted. Before painting in the middle of summer, all the boards were removed (luckily everything was held on by galvanized screws). The boards were lightly sanded with a hand-held electric planer so that burrs would not stick out and the paint would go on more evenly. Since the boards had completely dried out in a couple of years and had been trimmed, we had to screw them into new places close to each other, but without much fanaticism. Everything was done quickly without any gaps and painted with a covering antiseptic "Vinha", which was used to paint the whole house. Imagine my surprise when, having arrived at the dacha in the fall (the fall turned out to be unusually rainy), I discovered that where the boards at the bottom were screwed onto one solid beam of the porch frame, the boards were torn off and extended beyond the porch by almost 5 cm! Taking into account the fact that the boards are no more than 1.8 m in width, and they were not exposed to direct precipitation (maximum rare slanting rains on a well-painted surface).
Since it was already quite cold, I didn’t do anything, leaving it for next year. The first photo below shows what happened to the galvanized 4x40 mm self-tapping screws: the self-tapping screws in the six outer boards (out of a total of twenty) were broken into 3 parts. The first part - the head and body 0.8-1 cm was in the board outside, part of the body about 1-1.5 cm protruded from the board inside, and about 2 cm remained in the beam of the porch frame, of which only a few pieces turned out, and most Couldn't catch it. Therefore, I had to screw the boards with self-tapping screws under small angle so as not to get into the debris remaining in the beam, Fig. 2.
Self-tapping screws for frame construction must be used with caution. Many novice developers make their choice in favor of screws. They believe that it is threaded connection will give the structure strength and durability. Great expectations are placed on galvanized self-tapping screws regarding their corrosion resistance. Nails are undeservedly forgotten today. For some unknown reason, these strong and reliable hardware are considered a relic of the past. Few people want to swing a hammer for hours and risk injuring themselves. With screws everything is much simpler: they are simply screwed into the wood and can be easily removed if a mistake is made. In fact, when deciding whether to use screws or nails when building a frame house, one cannot be categorical. Both types of fasteners can be used. Let's look at the pros and cons of each type.
To work with wood, it is necessary to purchase screws with a wide pitch between threads. Metal hardware has a smaller diameter and thread pitch. They do not provide the necessary fastening strength, since wood is much softer than metal.
When choosing screws as fasteners for a frame house, you should consider a number of factors:
- The products are quite expensive. It is an order of magnitude higher than that of nails. To assemble numerous frames, several thousand screws will be required. And this will cost a lot of money.
- The screws are made of hardened metal. They can only be used in connections where the load is due to pull-out. Under transverse pressure, metal breaks easily.
- If the self-tapping screw breaks, it will be impossible to remove the broken fragment. This can be a problem if precision work is being done.
- The screws are screwed in using a screwdriver. If you use an electric tool, there will be inconvenience with the cable. The battery life of the device is limited. After just an hour of operation, both batteries will run out. Construction will be suspended.
- To tighten wooden fragments, you need to use screws with threads only on the lower part. This is the only way to achieve a tight and reliable screed.
However, you should not unequivocally refuse to use screws in the construction of a frame house. You cannot do without self-tapping screws when installing locks, mounting corners and hinges. Threaded hardware is needed when working with fragile materials that are destroyed by impact.
When conducting finishing works special self-tapping screws with a drill at the end and a wide head are used.
Such hardware is used to fasten drywall and siding panels. Using screws, you can attach thin sheathing strips by first drilling holes in them. The corrugated sheeting is screwed to the sheathing using special screws and rubber washers.
When deciding which screws to buy for construction, you should not choose zinc-coated products. They cost much more than ordinary hardware, but they also rust from moisture. It's better to spend money on screws from of stainless steel. They will last for decades without loss performance characteristics. Stainless steel hardware can be unscrewed when dismantling the building.
Choosing nails
These products have a long history of use in the construction of wooden buildings. When a nail is driven into wood, its fibers move apart and the metal is tightly compressed. Even a smooth nail provides a fairly tight fixation of parts. In terms of shear load, it is almost impossible to break a nail. It may bend, but not burst. More likely, a timber or board will crack. To ensure reliable tear-off, it is necessary to use threaded or serrated nails. Such products work no worse than expensive self-tapping screws.
Let's look at what nails can be used at various stages of construction:
- When creating a floor. As a rule, a multi-layer cake is created from boards and timber. Logs can have a thickness of up to 150 mm. They need to be fastened to the beams with smooth nails 200-250 mm long. Floor boards must be nailed to the joists using screw nails, the length of which is 2 times the thickness of the board.
- When installing the frame. It is assembled from timber with a section of 110x50 mm. Best choice To fasten such fragments together, 100 mm notched nails are used.
- When installing the casing. The thickness of the boards for internal and external cladding varies between 20-30 mm. The best option is to use 60 mm notched or threaded nails.
- When covering with clapboard or block house. In order not to spoil the appearance of the cladding with hardware, it is advisable to use nails without heads. The length of such products should be 2-3 cm greater than the thickness of the skin.
- When installing windows. Nails are only used if window frames attached to the walls using plates. If fulfilled through mount, then long self-tapping screws or anchor bolts are used.
When working with nails, you must use hammers different weights and configurations. To drive nails 100-200 mm long, you must have a tool weighing at least 1 kg. Products middle length(50-100 mm) must be hammered with a hammer weighing 300-500 g. When working with hardware for finishing, a small hammer weighing 100-200 g is sufficient. It is better to buy nails in bulk.
The nodes of a frame house are called important places, which must be built in a certain way so that they fulfill the role that is inherent in them by technology.
Several dogmas of frame housing construction.
1. The frame house must be assembled on nails. Any statements that it can be assembled using screws or corners are unnecessary myths for frame house construction. Builders all over the world are building frame houses on nails(except for the Japanese, who build them on huge wooden pins and from huge timber, but not on self-tapping screws). The hack builders will try to convince you otherwise, but don’t believe them. Trust me and the building codes.
2. In a frame house practically not used iron corners. They are not needed there. The exception is working with trusses, where they are used for ease of installation. This rule does not apply to steel “boots”, which are used to hang the joists of a house or terrace from the beams “from the side”. Although this connection can often be replaced with a “support board” connection.
3. For a frame house they are used nails 90 mm(frame) and 60-70 mm (floor and trim). Large nails are not required even when working with 50 mm thick boards, and even more so if you have a frame house made of 40 mm thick boards. Reinsurance with the use of large nails is unnecessary and only leads to an increase in the value of the house.
So, let's move on to specific nodes and nail fights in them.
Frame house floor
How to nail a second floor joist frame to a double wall frame (this is also true for the first floor):
Fastening the joists of the second floor (also valid for the first floor):
The impact of nails in the floor joists through the joist strapping (this is also true for the first floor, where instead of the strapping there is a bench or):
Nail connection of the floor joist on the central load-bearing wall of the frame:
How many nails need to be driven into the joist lintel above the central support:
Marking subfloor slabs
Subfloor and its fastening to the floor joists (this is also true for covering walls with slab material):
Frame house walls
We hammer nails into the lower frame of the wall: 
Upper frame of the house wall to the wall studs:
We knock down the wall frame posts to bottom harness and black floor:
We attach the frame racks in the middle of the house to the bottom frame and floor joists in the middle of the house:
The second top frame of the house is attached to the bottom frame and frame wall posts:
Double post of the opening for the header:
Nails in the header of a window (opening) at home:
Jib in the wall of the house:
Additional board for attaching gypsum boards to the ceiling:
You can often hear the opinion that frame houses are one of the simplest, most rational and inexpensive types of building structures. Based on this idea, many developers choose frame technologies for construction, thinking about savings and even the possibility of building a house on their own. Unfortunately, the idea of the simplicity and cheapness of frame technologies applies only to those buildings that do not comply with any building codes and rules, which are erected by guest workers and inexperienced DIYers. However, the same can be said about building log houses from wood with your own hands.
Frame technologies really have many advantages, but only in cases where the house is being built experienced builders from industrially produced components for frame house construction. An inexperienced or illiterate builder, working with frame technology, can make many more mistakes than when building a house from solid wood or stone materials. Where, when building a house from massive wall materials only a few technological operations are required, frame technologies will require a much larger number of technological “passes”. At more operations, the risk of making mistakes, non-compliance with technology and improper use of materials increases significantly. Therefore, frame houses built without a project and the involvement of qualified specialists “at random” or on trust in guest workers may be short-lived and will soon require overhaul due to unsatisfactory consumer qualities (freezing, wet insulation, high heating costs, rotting of structural elements, destruction, as individual elements, and the entire structure as a whole). Unfortunately, in Russia the list of regulatory construction documentation for the design and construction of frame houses is significantly limited. Currently, the 2002 set of rules SP 31-105-2002 “Design and construction of energy-efficient single-apartment residential buildings with wooden frame”, developed from the outdated 1998 National Housing Code of Canada.
In this article we will provide a brief overview of the main errors and violations of frame house construction technology.
Construction without a project.
This is a universal “general” mistake when choosing any construction technology. However, it is in frame technology the cost of mistakes can be especially high and lead to cost overruns instead of savings, both due to the use of an excess amount of material (frame made of large-section timber) and the need for repairs due to insufficient sections of beams, a rare step of their installation, destruction of structural elements due to for unaccounted loads, incorrectly selected connection methods in nodes and fastening materials, biological destruction of wood due to impaired steam and moisture removal.
Wood construction " natural humidity».
Almost nowhere in civilized countries are houses built from raw wood, just as before in Rus' they never built houses from freshly cut tree trunks. SP 31-105-2002 clause 4.3.1 states: « Bearing structures(frame elements) of houses of this system are made of lumber coniferous species, dried and protected from moisture during storage.” Raw wood is only a semi-finished product for the production of building materials. In Russia, sellers and suppliers delicately call raw lumber wood of “natural moisture.” Let us remind you that a freshly cut tree has a humidity of 50-100%. If the wood was rafted on water, then the humidity is 100% or more (the amount of water exceeds the amount of dry matter). “Natural moisture” usually means that the wood has dried out slightly during processing and transportation, and it contains between 30 and 80% moisture. When drying in the open air, the amount of moisture is reduced to 15-20%. The normal equilibrium moisture content of industrially dried wood in contact with the atmosphere will be a moisture content of 11-12%. When drying wet wood, the length of lumber is reduced by 3-7%, and the volume of wood by 11-17%. The use of “natural moisture” wood for the construction of frame houses leads to uncontrolled shrinkage of the wood, which changes the linear dimensions of structural elements and can lead to deformation, cracking and rupture of the wood with destruction of fasteners. When a wooden frame dries out, numerous cracks and gaps open up, significantly increasing the thermal conductivity of the walls of a frame house, tearing insulating materials preventing the penetration of moisture. When wood shrinks, its density increases, which leads to better conductivity of vibrations and sounds.
Construction from lumber without preliminary antiseptic treatment.
Even in the most properly designed frame house, a certain amount of condensation is inevitable on the media sections, of which there is much more in frame houses than in buildings made of solid materials. A moistened tree containing polysaccharides in its structure is an excellent nutrient medium for various forms microflora and microfauna, representatives of which are capable of destroying the structure of a tree in a short period of time. SP 31-105-2002 (clause 4.3.2) states that all wooden elements located closer than 25 cm from ground level and all wooden elements not made of dry wood are subject to antiseptic treatment.
Incorrect use of materials.
In classical frame technology, the corner posts of the frame should not be made of timber or three boards knocked together closely - in this case, increased heat loss through the “cold corners” is ensured. Correct " warm corner"is assembled from three vertical racks, located in mutually perperdicular planes.
Materials that can bear loads are used to cover the frame. For example, OSB must be structural and intended specifically for outdoor use.
Insulation of vertical frame walls is permissible only with rigid insulation boards. Due to shrinkage and sliding over time, fill-in and roll insulation can only be used on horizontal surfaces or in roofs with a slope of up to 1:5. When using economical versions of low-density insulation slabs, it is recommended to secure each row of slabs with spacers between the slabs to prevent slipping. This solution makes the structure more expensive and increases the thermal conductivity of the wall, so it is more profitable to use high-quality, more expensive insulation more high density. The size of the openings between the frame racks should not exceed the transverse size of the insulation slabs - 60 cm. It is even better if the size of the opening is reduced to 59 cm in order to eliminate gaps between the racks and the insulation slabs. You cannot fill the walls with scraps of insulation - there will be many gaps.Incorrect fastening of materials.
Black self-tapping screws can only be used for fastening sheet materials. The use of black self-tapping screws in a load-bearing frame, especially in a frame made of damp wood, can lead to the rupture of these unreliable fasteners that have low shear strength.
In all cases of assembling the load-bearing elements of the frame, galvanized nails or chrome-plated or brass-plated screws with a minimum diameter of 5 mm are used. The use of perforated steel fasteners without ligating wooden elements does not always guarantee the design strength of the frame.
Fastening elements for beams and other elements power frame It is unacceptable to attach it to OSB boards, especially with nails.
When nailing sheet elements using nails or screwing them with self-tapping screws, it is unacceptable to recess the head or head deeper than the plane of the surface of the material. From the point of view of structural strength, the deepening of the head or cap by half the thickness of the material is considered a missing fastening element and must be duplicated with a correctly installed screw or nail.
Minimum distance from the edge of the covering material to the cap or head of the fastener is 10 mm.
Since 2012, the International building code for residential buildings (International building code, paragraph 2308.12.8) requires to prevent shifting during earthquakes, wind loads, etc. secure the frame of all newly erected frame buildings to the foundation with anchor bolts through pressure plates measuring at least 7.6 by 7.6 mm with a steel plate thickness of at least 5.8 mm. The minimum diameter of bolts or anchors is 12 mm.
Construction of frame houses using “innovative” technologies.
The most common frame construction technology in the world involves the sequential assembly of “platforms” - floors with floors, followed by the assembly of walls on them and their installation in a vertical position. In this case, it is convenient for builders to move along a continuous surface, it is convenient to work with materials, any deviations from the design position can be eliminated before the construction of walls begins, and the floors themselves rest securely on the underlying structures. For some reason, domestic builders are trying to invent their own options for building a frame house with assembling walls “on site”, mixing the technology of building a frame house with the technology of half-timbering or “posts and beams” with the installation of floors last, which is fraught with the need for inserting or “hanging” floor beams, the need to move on temporary flooring, with high probability be injured if you fall from a height.
Errors in working with floor beams of a frame house.
Most mistakes are made with the fastening of beams. It is best to rest the beams on the top frame load-bearing walls, for runs. It is prohibited to reduce the cross-section of the beam by cutting down the cutout for joining with the trim. If it is necessary to connect the floor beam with the strapping beam or beam purlin, it must be secured through a backing support bar with nails, or using steel beam supports. The steel beam support must have a height equal to the height of the beam and be fastened with nails through all mounting holes. Fastening beams using smaller supports, not punching through all fastening holes, fastening with black self-tapping screws, fastening only with nails without a support bar are mistakes.
The most common spacing of floor beams in the world practice of frame house building is from 30 to 40 cm. This spacing of beams makes it possible to obtain strong floors that do not sag under shock load. The installation of floors with a pitch of more than 60 cm is generally not recommended. The minimum thickness of sheet materials for flooring on floor beams is 16 mm for a beam spacing of 40 cm.
Often beams-purlins that work in bending are assembled from boards flat, rather than installing them on an edge.
Load bearing capacity floor coverage increases if the covering sheet material of the subfloors is additionally glued to the floor beams.
The load-bearing capacity of frame floors can be increased due to rigid cross-links beams Such connections are installed in increments of 120 cm and can serve as support for internal non-load-bearing partitions (through the subfloor). Also, transverse struts serve as an obstacle to the spread of flame during a fire.
How to properly drill holes in floor beams:
I-beams:
Composite I-beams can only be cut or drilled in certain locations per the manufacturer's specifications. The upper and lower elements of I-beams must not be disturbed. No more than 3 holes are allowed per beam. One hole up to 40 mm in diameter can be drilled in any part of the I-beam except supporting parts. I-beams glued Wood-OSB-Wood are designated “Top”. At self-production beams based on OSB, the direction of the force axis of the material should be taken into account.
Floor beams made of sawn wood:
Errors in working with the cladding of a frame house.
According to foreign building codes and recommendations of the American Engineered Wood Association (APA), the frame can be sheathed with OSB boards both vertically and horizontally. However, if the OSB board is sewn along the frame posts, then the force axis (indicated on the OSB panel by arrows and the inscription Strength axis) will be parallel to the posts. This arrangement of the plates is useful only for strengthening weak frame struts that work in compression without significant lateral and tangential loads (which is almost unrealistic in real operating conditions). If OSB boards are sewn perpendicular to the racks, they strengthen the building frame to absorb tangential and lateral loads that arise when exposed to wind and base movements due to soil movement. Particularly relevant is horizontal cladding of OSB panels in frames with missing slopes, to impart the required structural rigidity. If OSB sheets are laid across the racks, then the force axis will be perpendicular to them, and the OSB sheets will withstand greater compressive and tensile loads. So, for example, in the domestic SP 31-105-2002. "Design and construction of energy-efficient single-family residential buildings with a wooden frame" provides (Table 10-4) the recommended parameters for the minimum thickness of plywood for cladding the frame: if the plywood fibers are parallel to the frame posts at a pitch of 60 cm, then minimum thickness plywood is 11 mm. If the plywood fibers are placed perpendicular to the posts, then thinner sheets with a thickness of 8 mm can be used. Therefore, it is preferable to sew OSB sheets with the long side not along, but across the racks or rafters. For the outer cladding of one-story frame houses, OSB 9 mm thick can be used. But during construction two-story houses and any houses in the zones strong winds The minimum thickness of OSB for external cladding is 12 mm. If a frame house is sheathed with soft fiber boards of the Isoplat type, then the frame structure must have jibs that provide lateral rigidity to the structure.
Between everyone sheet materials The sheathing should be left with gaps for thermal expansion of 2-3 mm. If this is not done, the sheets will “swell” as they expand.
Joining of sheathing sheets is carried out only on racks and cross members. The sheets are sewn “staggered” to ensure greater strength of the load-bearing frame structure using chain ligation. External cladding should connect the wall frame with the lower and upper trim.
« Pies" of the floors of the walls and roof of the frame house.
The main mistake in the design of frame pies for floors, walls and roofs is the possibility of the insulation getting wet from moisture penetrating inside. The general rule for building walls in heated rooms is that the vapor permeability of materials should increase from the inside out. Even in the floor, where they often do the opposite: a vapor barrier is laid on the ground side, and a vapor-permeable membrane on the room side.
Any insulated frame house pie must have a continuous layer of vapor barrier from the inside. “Continuous layer” really means that the vapor barrier should not have any defects: the sheets must be glued together with an overlap along the entire protected contour, without exceptions. For example, almost all builders at the stage of assembling the frame forget to lay a vapor barrier under the junction of the internal partitions with external walls according to standard schemes connection devices of clause 7.2.12 SP 31-105-2002.
Additionally, all gaps between the sheet materials of the sheathing in wet areas and the roof must be taped waterproofing materials to prevent moisture from getting inside the insulated “pies”.
In addition to preventing moisture from entering the insulated cake, it is necessary to ensure that moisture is removed: from the outside frame wall should either be covered with OSB boards, which is a “smart” vapor-permeable material that can increase vapor permeability when the environment is humidified, or protected by a semi-permeable membrane that ensures the removal of moisture from the insulation. Cheap single-layer membranes have unsatisfactory vapor permeability and require a device air gap between the insulation and the membrane. Also, cheap single-layer membranes provide poor protection against moisture penetration from the outside. It is preferable to use expensive superdiffusion membranes, which have really good vapor permeability and can be mounted directly over the insulation.
Ventilation of a frame house.
Figuratively speaking, the interior space of a properly built frame house is identical internal space thermos: heat loss through the walls is very small, and moisture transfer through the walls is most often practically absent (but may persist during use). Accordingly, it should be vented outside. Without a thoughtful one, this becomes impossible. In a frame house, each room must have ventilation valves, or the windows must have a micro-ventilation mode or built-in slot ventilation valves. Should be installed in the kitchen and bathroom exhaust ventilation. Abroad frame houses for permanent residence practically no one builds without supply and exhaust ventilation with a recovery system.
At the end of the article, we present illustrations of the widespread “folk” construction of a frame house, in which, upon closer examination, there is not a single correctly executed element.
The typical mistakes that we described in the article are easily preventable. Before you start building your first frame house or hiring builders, study in detail the albeit slightly outdated, but the only set of rules for frame house construction available in Russian, SP 31-105-2002. By paying attention to all the details and subtleties of creating a power frame of a building and ensuring the durability of its operation, you can avoid costly mistakes when building or ordering your frame house.