Future home owners are increasingly choosing frame construction. There are many advantages to such buildings. Construction takes a minimum of time, wood is the most environmentally friendly pure material, provides comfortable living. The main task of builders is to carry out all work according to proven methods and use high-quality materials. The customer should know the basics of construction. For example, how to properly build a corner of a frame house and make it warm.
The warm corner of a frame house must be built taking into account all standards
Organization of external corners
The main task of the corner is to rigidly join adjacent wall structures and minimize cooling bridges.
There are several dozen construction schemes external corner frame house. For cold regions, only three methods are suitable. But two are the most popular.
The most common schemes for the corners of a frame house are described below
The simplest option
The “California” corner assembly is a leader among others. At the docking point wall structures With inside a board is nailed or narrow panel OSB. It firmly holds the walls together. In the future, the nailed strip serves as a support when installing the inner layer of the wall, allowing for high-quality interior finishing.
Second place
The so-called “Closed” corner ranks second in popularity. The point comes down to installing an additional rack in inner corner between wall studs or bars, resulting in a shelf on the inside corner side. The design retains heat. In this case, it is enough to insulate the building only from the outside, but do this before covering it with sheets.
The warmest option
The “Scandinavian” option is used quite rarely. Experts determine that this is the warmest corner in a frame house; this is achieved due to the maximum cutting off of cold bridges. The design maintains the necessary rigidity. The disadvantage is the complexity of the work.
When assembling the frame with your own hands, experts recommend choosing method 1 as the simplest.
The outer corner can also be made in the form of the letter “P”, and three short blocks can be fixed on the inside.
Organization of internal corners
Angle between outside and internal wall buildings are made in several ways.
The first option is the following:
- between 2 beams, one regular beam or three short ones are installed (in the top view the letter “P” is obtained);
- A wall element is attached to the middle beam.
Second option (especially heat-intensive):
- the outer wall at the junction with the internal stand is made up of horizontal bars 50x50, located between the vertical bars, with a pitch of 60 cm;
- A vertical post is installed to the horizontal bars, forming the edge of the inner wall.
The blocks are knocked together only with 90mm nails every 50-60 cm.
As practice shows, not all construction teams offering services to individuals are proficient in the technology for making corners.
Warm corner technology
It is often believed that it is enough to install three racks, and the corner will be sufficiently protected from freezing. IN very coldy Ice and frost form in such corners.
According to advanced technologies, the corner of three racks gives off heat perfectly, so it is covered with insulation:
- a beam 50 mm thick is stuffed on the inside and a layer of insulation is laid;
- With outside– also one layer of insulation.
As a result, the thickness of the laid insulation increases to 25 cm, resulting in the correct warm corner of the frame house.
On our website you can find contacts of construction companies that offer. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
Methods for tying corners
The following schemes for tying corners are trusted by builders:
- The simplest and most popular option among builders. A right angle is formed from 2 beams (one beam is placed on the edge of the other), the assembly unit is installed on the rough surface of the floor, and its top should be directed towards the corner posts.
- "One-sided groove." Initially, grooves are cut out in one block, then counter grooves are cut out in another block so that when installing the bars to each other, a right angle is obtained. The ends of the beams should extend 10-15 cm from the top of the corner; the top view should resemble a cross.
- The connection principle is similar to the first method. In one block, a “spike” 4-5 cm high is cut out along the end in the center. In the other block, a counter groove is cut out, its size slightly smaller than the “spike”. Next, the bars are tapped to each other at 90 0 so that the “tenon” fits tightly into the groove.
- "The Secret Thorn" The method resembles the previous option. Only the shape of the groove and the “tenon” changes, in which one bar is installed to another along a vertical plane. There should also be a right angle between the bars.
Vertical posts in corner joints are secured using corners and wood screws. The stability of the structure is guaranteed by reinforced galvanized corners; this is the best option.
Corner trim
There are several ways to sheathe the corners of a frame house:
- Nails, 150 mm long. 4 nails will allow you to securely fix the angle. There must be at least 2 cm from the place where the nail is installed to the edge of the beam. This prerequisites at correct assembly.
- Anchor fastening guarantees the necessary reliability and strength of the result.
- Dry oak is most suitable for using wood pins. Dowels with a diameter of 20 mm are cut out. The holes are made, their length should exceed the length of the dowel by 1.5-2 cm, and the diameter should be made slightly smaller. Do not drive the dowel into the hole completely; leave approximately 10 cm above the surface. This part will be needed for the next step when forming the corner.
Video description
Even more information about correct installation Watch the corners of a frame house in this video:
Materials used
The basic rule is to use spruce or pine bars to build a warm corner. It is correct to use boards whose thickness is in the range of 38-50 mm (50 mm is ideal), with a width of 200-250 mm.
It is an absolute misconception that 150x150mm or 200x200mm timber meets the requirements for corner construction. This material provides the necessary rigidity, but contributes to significant heat loss. The beam in the corner does not leave any free space for laying insulation.
Quality requirements
Only dry material is used (humidity does not exceed 19%) with ideal cross-section calibration; the number of defects should not affect the strength of the wood. Dried timber, passed heat treatment in a specialized chamber, eliminates deformation and development of cracks in the future. In addition, the material is impregnated with a special fire-retardant composition, which increases the durability of the wood. You can apply the composition to the bars yourself; the antiseptic “Senezh” is suitable for this.
Often purchase quality material difficult, and also quite expensive. Cost of processed board relative to wood material natural humidity approximately 2 times more.
Keep wooden materials It is better under a canopy, laid on a special flooring. This will maintain strength and straightness characteristics. Calibration differences of 3-5 mm are subject to mandatory correction, which increases the time and complexity of the work.
A complete replacement for a block is a double or triple edged board using bolts or studs. This option is more economical in price, but working with such material takes a lot of time and labor.
Edged board will become an affordable replacement for expensive timber
Common mistakes
To the owner during the assembly of his future country cottage must be kept under your own control important stages construction process.
Wrong choice of materials
Do not use wood materials with natural moisture. For example, untreated softwood has a moisture content of approximately 40%. The humidity of the “working” material is 14%. As the tree dries out, it shrinks in size and becomes deformed. What happens to the house when the wood in the corners dries out? Firstly, the necessary rigidity of the frame will be lost. Secondly, cracks and additional cold bridges will appear.
Selecting materials with insufficient cross-section. According to GOSTs of the Russian Federation during construction frame houses use bars with a thickness of at least 40 mm and a width of 150 mm. A frame built from bars less than 35 mm thick does not have the necessary strength reserves.
Errors with fasteners
The correct choice of fasteners is an important point.
Experienced builders, when constructing corners in a frame house, never simultaneously use perforated corners and black self-tapping screws, intended exclusively for fixing drywall. Data fasteners They are easily installed in wood, their cost is not high, but together they cannot provide the necessary safety margin.
It is permissible to use yellowish or silver self-tapping screws; their thickness should not be less than 5 mm. In this case, the use of a perforated corner is permitted.
The frame itself is fastened only with nails no less than 90 mm long.
Not all builders know the design features of a frame building. When forming angles, mistakes are often made:
- use timber;
- They simply nail three boards to each other without forming warm bridges.
When choosing a construction team, it is worth learning more about the work schemes and asking questions that arise. If a clear and concise explanation is not forthcoming, the competence of the workers should be questioned.
Conclusion
In general, when constructing a frame building, the following factors should be optimal:
- strength of the building;
- consumption of materials;
- labor intensity of work.
Insufficient indicators will bring numerous problems with the house during its further operation. Exceeded values will result in increased construction costs.
Building a frame house is similar to assembling a construction set. The wooden frame house is assembled in accordance with the diagram. At the same time, the strength and reliability of the future structure depends on the quality of the assembly components. What are the features of the main components and connections of a frame house? And how to properly fix the lower and upper trims, racks, jibs, and crossbars?
Bottom trim connection nodes
The lower one is a frame made of wooden beams or several boards knocked together, which is laid on top. So-called planks - boards - are placed on the concrete foundation under the bottom frame. They perform the main function - they level the foundation and hide those flaws that could have been made during its pouring.
The beds are attached to the concrete foundation using anchors. The installation sites are located at a distance of no more than 0.5 mm. In this case, at least the ends of the beams are secured with anchors.
Connection of the beam to the concrete foundation.
To install anchors, holes of a certain depth are drilled. They pass through the board and go deep into the thickness of the concrete foundation. The depth of drilling and driving in the anchor is determined by the height of the house wall and the design of the foundation. For traditional 2.5-3 m frame wall on concrete base The depth of lowering the anchor into concrete is 15-20 cm.
The second option for installing anchors is to concrete the anchor studs during the process of pouring the foundation. When casting concrete slab or tapes in specified places, hollow cones with internal thread. After the concrete has hardened, anchors are screwed into these elongated cone-shaped studs.
Features of the anchor connection
- The holes in the beam are drilled 2-3 mm larger than the diameter of the anchor pin.
- Wide washers can be placed under the heads of the anchor bolts to increase the area of their contact with the wooden surface and increase the strength of the fastening joint.
Anchor fastening of the lower trim. Before fixing, mandatory waterproofing is carried out - roofing material is placed on the concrete or its surface is covered with a special waterproof compound, mastic. After installation, check the horizon. Deviations from horizontal level allowed in sizes no more than 0.5° per 3 m.
Bottom trim assembly on a columnar foundation
The fastening of structural units of a frame house described above is used on strip and slab foundations. For columnar bases, a different scheme is used:
- For ease of fastening, the upper part of the columnar supports should have a flat horizontal head with holes.
- Place on top of the headrest wooden beams, which perform the function of a grillage.
- Recesses of the required depth are drilled in the beams. They are drilled under the holes in the headband.
- Fix the beam with bolts or screws.
Trimmed plank strapping on pile foundation. On a note
It is necessary to attach the timber to the foundation. Shallowly buried strips and slabs are subject to significant movement when freezing. Reliable connection The upper and lower frame ensures the reliability and durability of the entire structure.
Design of frame house components
Vertical frame posts are installed on top of the lower frame and secured with nails. Fastening with metal corners is used for T-shaped connection of beams without cutting. It's easier to do. Fixing beams with metal nails is used at the junction with partial cutting of the lower beam. This is a more difficult connection to do with your own hands.
A joint without cutting is used for corner frame supports. Butt joints with fixation with plates or corners are used in the main components of a frame house, if the construction is carried out with your own hands, without the involvement of professionals. If experienced builders work, they use a connection with a partial insertion. It prevents strong movements of the timber and frame boards when drying out.
On a note
The size of the cutting for the vertical frame post is 30-50% of the thickness of the bottom trim beam.
The corner joint without cutting is fixed with metal plates using wood screws. In this case, reinforced steel corners with several perforations are used. As well as durable self-tapping screws in light golden and silver colors.
Strengthening the corners for fastening the corners of the house is carried out due to technological processing - the metal plates are hardened during the manufacturing process. Or through the use of metal with a large section thickness, up to 2-3 mm.
Methods of fastening racks. A notch joint is often used to attach studs in the middle of a wall. The supports are inserted into the prepared recesses and additionally secured with nails. Then they are secured in a vertical position with jibs - diagonally inclined slats that rest against a vertical post on one side and a horizontal frame on the other. For ease of support, the ends of the jib are made beveled - part of the end is cut off.
Temporary jib
During the assembly of the frame, temporary jibs are also installed, which fix several vertical racks. Temporary jibs are placed between the upper and lower trim at an angle. They connect several vertical posts and are fixed with nails.
Temporary jibs are placed on the outside of the frame. To attach them, you do not need to cut down, but they need to be fixed in such a way that upon completion of construction, the temporary auxiliary beams can be easily dismantled. Therefore, nails are used to fix them.
Temporary jibs for racks. Temporary jibs hold the posts upright until permanent jibs are installed at the bottom and top of each rack. Once the permanent jibs are in place, the temporary fixing beams can be removed.
On a note
The construction project contains a description of the frame components wooden house in the drawings. They often do not describe in detail the method of attaching temporary jibs, since they do not bear the main load and support the frame temporarily.
Upper harness knots
The top frame of the frame house is laid on vertical frame supports after installing the corner posts. If the perimeter of the house is large enough (more than 6 m), then in addition to the corner pillars, intermediate ones are also placed - in the middle of the wall. And only after that the top harness is placed.
After laying the top row, temporary jibs are attached - across the entire wall. Next, attach the remaining vertical posts and jibs to them. After which the temporary jibs between the upper and lower trim are removed.
It is most convenient to assemble the walls of a frame house in a lying position, knocking together the lower frame, vertical posts, crossbar, jibs and top frame. And only after that raise the walls in vertical position, where all that remains is to fasten all the walls of the house together. To firmly connect the walls of a frame house, a second top frame is used, which is overlapped with the first top frame.
Double top knots. When using a double top trim, you can do without the use of steel corners. In this case, there is no need to partially cut off the ends of the boards, making a “claw” connection. Because such connections with cutting out part of the end violate the integrity of the board and, accordingly, weaken it.
Beams are placed on top of the second top frame interfloor covering. The beams are laid on the end, the distance between the beams is set depending on the size of the spans and fastened with nails.
Wall corner
The corner of a frame house is the place of maximum heat loss. As a rule, it is in the corners that condensation accumulates and it is them that need to be insulated first. Therefore, even at the stage of assembling the frame, it is necessary to ensure that the corners of the future frame house are warm. How to do it?
Smooth fixing plates are placed on the outside of the vertical beam. They connect adjacent single-level surfaces of the vertical post and horizontal beams. The fixing corners are located on the side. They connect mutually perpendicular surfaces. What else is important to know about angles?
When building in regions with cold climates, not solid wooden beams are used as vertical posts, but a corner post is assembled from separate boards. The resulting structure resembles a well. Insulation is installed in this internal space, which retains heat and limits possible heat loss.
Installation of corners in the frame of the house. It must also be warm; for this, single racks are used, but the load on window and door openings is removed using a crossbar. The crossbar is fastened along the entire length of the frame wall by cutting into all vertical posts. It is important to take into account that under each window opening There should be at least 1-2 vertical support boards.
Knots of the rafter system
The nodes of the rafter system include all connections between its elements, namely:
- Fastening floor beams to the top frame.
- Attaching the rafter beam to the top trim.
- Fastening the racks on the gables to the top trim and to the outer rafters.
- Attaching the internal posts to rafter bed and to the skate.
- Fastening struts - inclined beams that support the rafters and rest on the beam.
- Attaching the crossbar to inclined rafters.
- Fastening the sheathing.
Knots of the rafter system. The fastenings listed above can be done using corners or using nails if the elements of the rafter system are connected overlapping each other.
Fasteners
The following elements are used as fasteners for the components of a frame wooden house:
- Fastening plates (angles or flat plates with or without holes). Plates and angles are attached to beams or supports using wood screws.
- Staples (straight and angular) are wire fasteners of a certain diameter. Their edges are bent and inserted into the ends or side surfaces of the beams.
- Bolts - used to tighten adjacent beams and rafters, inserted into through holes and secured in them with nuts.
- Nails.
All connecting, fixing and fastening elements for frame buildings are made of metal. To fasten load-bearing elements, reinforced corners made of hardened steel or increased thickness, 3-4 mm, are used. To fasten the supporting elements, angles made of ordinary steel with a thickness of 2-3 mm are used.
Variety of fastening elements. In order to protect against corrosion, galvanized steel is used for the manufacture of corners and plates. Rust protection is especially important in outdoor construction, when metal fasteners in walls can become a point of moisture condensation, causing a section of the wall to become wet. Therefore, galvanized fasteners are in great demand in various components of a frame house.
Node connection errors
A drawing of components requires the presence of sketches and descriptions. However, despite this, novice builders often make offensive mistakes. Let's list the main and most frequently repeated erroneous actions that novice individual builders make when assembling a frame:
Not all jibs are installed. This is not true. The jibs ensure the wall's resistance to wind loads. In addition to the jib, to withstand the wind it is necessary to use rigid slabs in the outer skin.
- Use solid timber or boards placed tightly next to each other as corner posts. This corner will be cold. Moisture will condense and mold will develop.
- Use “black” screws for fastening. They are not strong enough, especially if not enough was purchased for construction. dry wood. When drying and warping, the “black” screws can be simply “torn off”. A more durable option is golden and silver-colored self-tapping screws, galvanized or coated with a layer of chromating and phosphating.
- They use wood that is not dry enough, which causes severe shrinkage and “breaks” existing nodes and connections.
- And another mistake is not to use nails. These proven fasteners are often stronger than any self-tapping screws.
Frame construction is a new technology in which, despite its apparent simplicity, there are many nuances and features.
Today, this type of construction, such as the construction of frame houses, has become very popular. This is due to simple technology and the ability to do the work yourself.
A logical question arises: how, where to start, what to look for Special attention. Many people are concerned about how to secure a frame house. To answer all these questions, consider possible options frame construction.
Common construction methods
Device diagram corner connections in a frame house.
Everyone has heard at least once about the frame-panel construction method, but it is unlikely that they delved deeply into its essence. This method involves carrying out work using materials delivered to the actual construction site. This list includes beams various designs, thermal insulation and vapor barrier material, roofing elements, fasteners, etc.
Typically this option is done professional builders in strict accordance with the project. All parts of the house have special markings, with the help of which builders connect them into a single whole. Sheathing of the finished frame is carried out using OSB boards, followed by work on thermal insulation and wiring of various types of communications. And after all this work is completed, you can begin internal as well as external finishing works. Of course, it cannot be done without installing the roof; in individual cases, the issue of decorating the area adjacent to the house can be resolved.
Another method, frame-panel, consists of assembling finished panels, including frame parts, insulating material, etc., directly at the factory for their production. Ready-made parts and blocks of the future house are delivered to the construction site. These include steps equipped with windows and doors, pediments, roofing elements, floors, etc. The assembly of such a house is carried out very quickly - in a maximum of a week. The building turns out to be beautiful, cozy and, of course, very warm, which is important.
Any type of frame building includes in its design walls (external), partitions, ceilings and roofing. All these important elements are arranged according to the same scheme. The frame is made of wooden beams and is subsequently sheathed on both sides with some kind of sheet material. The void created inside is filled with modern and fairly effective thermal insulation materials.
Both of these technologies are quite common in our time and are considered the most promising in the field of private housing construction.
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Technological procedure for the construction of frame houses
The construction of frame-panel houses is, in fact, the assembly of a house from pre-prepared panels, similar to the LEGO set.
Before you begin construction, you need to take care of preparing the site and the materials you will need during the work process.
- The first priority will be building the foundation. After it is filled, you need to wait approximately 7 days. Everyone knows that required strength the foundation is built only on the 30th day, but despite this, the construction of a frame house can begin within a week. Your actions will not be destructive to the foundation; even professionals are of this opinion. For subsequent fastening of the lower trim made of timber to the frame, you can place special pins in it at the time of pouring the grillage. It is with their help that the fastening will be carried out. One end of the stud should be recessed into the foundation, and the other should be positioned vertically to its surface. The height of the stud (anchor) must be at least 10 cm. Please note that this is the height of the outer part; the anchor goes deeper into the foundation by the same value (10 cm).
- Having finished with the foundation, you need to take care of purchasing material for the frame. Wooden blanks the frame will subsequently be sheathed using OSB boards, which means they should also be purchased in advance.
- All wooden elements of the future frame must be treated with an antiseptic composition before completion. installation work, since it will be much more difficult to subject an already assembled frame to this procedure.
- Prepare materials for waterproofing in advance. Usually this is roofing felt. Even the cheapest of its types is ideal for this stage.
- You also need to take care of purchasing various fasteners in advance. It is difficult to determine how many of them you will need, since these fasteners break quite often, so think about the amount of stock in advance. Standard option provides for the purchase of fasteners in the following quantities: nails - 50 mm (1 kg), 100 mm (3 kg), 120 mm (5 kg); self-tapping screws - 50 mm (100 pieces), 100 mm (500 pieces). It is usually not difficult to purchase this mounting material.
- Now about the tools. You will most likely need:
- axe;
- hammer;
- screwdriver;
- saw;
- drill;
- building level;
- square;
- drills of different sizes;
- Fomka and some others.
- Thermal insulation material is also purchased in advance, since the size of the frame will depend on its quality, more precisely, thickness. Thicker material for thermal insulation requires larger size frame.
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Fastening points during the construction of a frame house
As it became clear from the above information, a frame house is durable and economical, and its construction does not take much time. But in order for your house to fully comply with these characteristics, you need to take care of the correct assembly of the fastening points of the frame building.
This process is quite complex, so before starting construction, it is best to carefully study the technology for assembling components.
The roof of a frame house can be covered with any materials that the developer likes. The main thing is that this process is carried out in compliance with all norms and rules.
Those who understand little about construction work, may wonder what fastening points are. The answer is simple: these are the connections between structural parts throughout the house. The most basic of them are floors, roofing systems and walls. Moreover, each of these main units has a number of important nodal fastenings in its design.
Below is a list of the most basic fastening points in a frame structure from bottom to top:
- fastening the bottom frame made of timber to the surface of the foundation; here you can also note the joining of the beams of the bottom frame to each other in corner joints;
- installation of vertical racks; Please note that the racks are installed first corner view, only then - the remaining non-corner posts;
- fastening the top trim made of timber; performing this task involves the same method as attaching vertical posts to the bottom trim;
- connections, the function of which is to strengthen the frame structure in horizontal and vertical planes; this will help the frame to be more stable, rigid and easier to withstand negative impacts of various origins;
- fastening the ceiling beams to the top timber frame.
- first of all, this is the connection of the rafters and the top trim;
- Next comes the connection of the rafters themselves in a place called the ridge;
- connection of rafters and crossbar;
- fastening the counter-lattice and rafters;
- and finally, the connection between the sheathing and rafters.
All of the above fastening points are load-bearing in nature; they will be responsible for the strength of the entire building structure. But at the same time, you should not lose sight of secondary fastening points, which include logs and interfloor ceilings.
In order to ensure high-quality fastening, special fasteners are used to connect various parts. Their development and production are carried out in strict accordance with the specifics of these works. Read more about these important elements below.
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Fasteners for the construction of frame houses
As already noted, for the reliability and high strength of a frame house structure, it is necessary to use only high-quality fasteners designed specifically for these purposes. Each fastening point involves the use of an individual type of fastening elements. Using them as fasteners, you can avoid complex connections, such as inserting or installing various so-called locks.
- The material for the manufacture of such fasteners is cold-rolled steel. The thickness of the workpiece varies from 2 to 4 mm. The size, structural shape, number and size of perforations and the presence of stiffeners directly depend on what types of fastening a particular fastening element is intended for.
- As for the perforation, focusing on its size, determine the thickness of the nails or bolts suitable for this fastening, and, of course, their number. This option allows you to determine without hesitation required amount nails (bolts), which will be needed to securely fix the connection, and you will also avoid cracking of the wooden components of the frame.
- The coating of fasteners varies, but in any case they undergo anti-corrosion treatment. Most often this is either a zinc surface, or primed, or using polymer-powder paint.
As mentioned above, this kind of connecting fasteners saves you from numerous and rather complex node connections that require certain skills. This is the implementation of a half-tree type insertion or the implementation of tightening locks. By making such connections, you reduce the strength wooden structure, since there is a reduction in the cross-section at the junction of the two parts. But the use of steel fasteners only increases reliability, creating additional reinforcement connections.
Frame wall angleDespite the apparent simplicity of the question “How to assemble a corner correctly?” the answer will not be so clear-cut. The simplest solution (choose reliable timber cross section 150 x 150 mm) - incorrect. This will create a risk of corners freezing in winter. For frame houses, you can offer 3 options, each of which will have its own pros and cons. Let's figure out which ones:
Option 1. Corner of a frame wall made of 4 boards
The corner of adjacent frame walls is assembled from 4 boards. Three posts nailed together are no different from a timber solution, so the pros and cons are obvious. The high strength of such a connection is combined with the risk of corner freezing. There is somewhere to attach drywall. You can reduce the risk of freezing if you put together a corner post not from 3 boards, but two with spacers from pieces (blocks). Mineral wool is placed in the cracks between the posts.
Option 2. Corner of a frame wall made of three boards 50 x 150 mm
The corner is assembled according to the 2 + 1 scheme, that is, we nail an additional post to one of the outer posts, turning it 90 degrees. The result is a fairly strong connection and there is a shelf for screwing the plasterboard of the internal walls. Obvious advantages: corner insulation is performed during the interior of the frame house. Also, for an additional rack, you can use low-quality boards, since in this unit the rack acts as a shelf for attaching drywall and does not bear a significant structural load.
Option 3. Corner of a four-board frame wall: 3 (50 x 150 mm) +1 (50 x 100 mm)
The appearance of an additional fourth board with a cross-section of 50 x 150 mm strengthens the structure, which is a plus, but at the same time it is necessary to insulate this corner in a timely manner. Moreover, this must be done before the appearance of the outer skin.
We nail two posts at an angle or parallel to each other with five black nails 90 mm long, the maximum pitch between nails is 600 mm. The distance from the edge to the first nail at either end of the posts is 150 mm.
You can often hear the opinion that frame houses are one of the simplest, most rational and inexpensive types 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 simplicity and low cost of frame technologies applies only to those that do not correspond to any building regulations and the rules of buildings that are erected by guest workers and inexperienced DIY enthusiasts. However, the same can be said about building log houses from wood with your own hands.
Frame technologies indeed have many advantages, but only in cases where the house is erected by experienced builders from industrially produced components for frame housing 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 soon require major repairs due to unsatisfactory consumer qualities (freezing, wet insulation, high heating costs, rotting structural elements, destruction like 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, there is a set of rules in force in 2002, 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 short review main mistakes 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.
Construction from "natural moisture" wood.
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 from softwood lumber, 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 on outdoors 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 fastening elements. When a wooden frame dries out, numerous cracks and gaps open up, significantly increasing the thermal conductivity of the walls of the frame house, tearing the 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 of microflora and microfauna, representatives of which are capable of destroying the structure of the 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. The correct “warm corner” is assembled from three vertical posts located in mutually perpendicular 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. Loose and roll insulation, due to shrinkage and slipping over time, can only be used for horizontal surfaces or on 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 of beams and other elements of the load-bearing frame must not be attached to OSB boards, especially with nails.
When nailing sheet elements or screwing them with self-tapping screws, it is unacceptable to recess the cap 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 sequential assembly“platforms” - floors with floors, followed by assembling walls on them and installing them 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 a high probability of injury when falling 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 construction is from 30 to 40 cm. This spacing of beams allows you to obtain strong floors that do not sag under impact loads. 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.
Load bearing capacity frame floors can be increased due to rigid transverse connections of the 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 40mm in diameter can be drilled in any part I-beam with the exception of 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 with 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-Apartment Residential Buildings with Wood Frames" provides (Table 10-4) the recommended minimum plywood thickness for framing the frame: if the plywood fibers are parallel to the frame posts at a pitch of 60 cm, then the minimum plywood thickness 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.
Gaps of 2-3 mm should be left between all sheet sheathing materials for thermal expansion. 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 chain binding greater strength power frame structures. The outer sheathing 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. General rule building walls in heated rooms - the vapor permeability of materials should increase from inside to outside. 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 exception. For example, almost all builders at the stage of assembling the frame forget to lay a vapor barrier under the junction internal partitions to external walls in accordance with standard connection diagrams in paragraph 7.2.12 of SP 31-105-2002.
Additionally, all gaps between sheet cladding materials in wet rooms and on 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 must be either sheathed 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 an 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 are practically not built 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.