In a high-quality frame house there are no trifles, and such a seemingly insignificant thing as fasteners generally takes on one of the main roles in importance. Without reliable and correctly selected fasteners there will be no reliable and durable home.
Important to use correct fastening not only for the frame of the house, but also for fixing the internal and external cladding.
Many future homeowners will not even think about such a “trifle”, at most asking themselves the question of what is better: screws or nails, which is quite understandable. Costs for purchasing fasteners and installation materials constitute a small part of the total construction cost frame house. It is much worse when they forget about correctly selected fasteners, or the builders themselves simply do not know. The other side of the coin in this matter is the regime of total savings on materials. With this approach, hardware is subject to reduction. In this case, the estimate will most likely include the most economical option, such as black self-tapping screws and regular construction nails. By and large, there is nothing wrong with such fastening options, but only if it is used strictly for its intended purpose, and not everywhere possible. For example, black self-tapping screws are indispensable as temporary fasteners; they are also perfect for interior wall cladding with board materials (plasterboard, QuickDeck) in preparation for finishing. The basic rule is to observe the purpose of the fasteners when building a frame house, apply it where it is needed and cope with its main task. To correctly assess the need to use certain hardware in the frame, you need to correctly assess what loads are acting in a particular node of the frame house.
To a popular question: What better than nails or self-tapping screws The answer can be given quite unambiguously that each fastener must be used for its intended purpose.
Look what happens to an ordinary hardened self-tapping screw when it takes a shear load. The self-tapping screw breaks at its weakest point and its head flies off, so using this type of fastener as a fastening for beam supports is strictly contraindicated. But in this place of fastening, special galvanized anchor nails with an annular notch and a conical head feel great. Such a nail has a diameter of 4.2 mm, and the conical head is wedged into the holes of the perforated fasteners, making it virtually impossible to cut off the head of such a nail, naturally, provided that a sufficient number of such nails are hammered in.
Be sure to consider the environment in which the fastener will be located.
When choosing options for using fasteners, it is necessary to take into account the environment in which it will be located. In places unprotected from precipitation, as well as in places where condensation is likely to occur, fasteners with special protective coating protecting against corrosion. For example, we choose hot-galvanized nails as fasteners for exterior wood trim, which have proven to be resistant to external factors. best side. We import such fasteners only from Finland, since Russian analogues with similar processing and similar characteristics do not satisfy us in terms of quality.
| Mounting location | Fastener type | photo |
| Attaching the strapping board to the monolithic base | Expansion anchor |  |
| Fastening decking boards To wooden joists | Structural Torx screw |  |
| Fastening the frame posts | Smooth nails for nails |  |
| Stitched (double, triple) frame posts | Rough / Screw nail for nailer |  |
| Stitched (double, triple) external posts | Rough/Screw galvanized nail or plated nail |  |
| Fastening joist supports, beam supports | Galvanized nail with tapered head and ring cut |  |
| Lathing, lath | Galvanized self-tapping screw, rough or screw nail |  |
| Soft roofing, Isoplaat | Galvanized roofing nail |  |
| The external cladding of the house is made of imitation timber. | Rough galvanized nail for nailer with galvanization. |  |
| Sheathing the house with windproof MDVP boards. | Galvanized roofing nail, galvanized staples 50-60 mm. |  |
| Fastening of structural beams, rafters, crossbars, tie rods | Galvanized stud, galvanized washers and nuts. |  |
Returning to the economic aspect of our article, I would like to mention that the price of special fasteners can reach up to 20 rubles. per piece, which is more than 60 times more expensive than the price of a regular black self-tapping screw 3.8*51 mm. On the scale of the entire construction project, where the total number of hardware amounts to tens of thousands of pieces, the amount is significant.
The cost of highly specialized fasteners can be several times higher than the cost of ordinary nails or self-tapping screws.
There is another unpleasant nuance that can “pop up” with dishonest developers, and which allows you to reduce the estimate on the total cost of fastening materials - this is the amount of fasteners used in a particular unit of a frame house. Less spent fasteners mean more benefits for the company, and in the absence of proper control, “extra” nails, corners and screws can go to satisfy the construction needs of a dishonest builder. With this approach, in some components of a frame house there is a risk of a very serious lack of reliability.
There are regulations that regulate required amount fasteners in each frame node, plus there are manufacturers’ recommendations building materials according to the required type and quantity of fasteners for fastening materials. In our work we try to focus on American and Scandinavian building standards, which are often stricter than Russian ones regulatory documents. For example, in Europe, if such standards are not observed, the house simply will not pass inspection by the responsible authorities. For us, compliance with such standards is the key to confidence in the maximum reliability of all our homes.
Over the last decade, screws and self-tapping screws have become so popular that we almost don’t remember about nails. At the same time in the West frame construction for the most part they only use nails. So which is better, nails or screws?
We conducted a small test to show one of the main disadvantages of screws, which many people forget about.
To prevent self-tapping screws or metal alloy screws from bending when screwed, they are hardened during the manufacturing process. After it, the metal becomes hard but brittle. This is the main disadvantage of screws and self-tapping screws. But to be precise, only galvanized self-tapping screws (white, yellow) are subject to hardening. Black self-tapping screws are usually made from oxidized steel C1022, although this is also relatively brittle.
The nails are not hardened, so they can withstand heavy loads better. If the load increases excessively, the nail will bend but not break, unlike screws or self-tapping screws. That is why they are still used in construction when assembling frames in areas with high loads. Screws are often assigned the role of fastening finishing materials.
Another advantage of nails is that with special nailing guns, the process of assembling structures is accelerated significantly.
Now a little test. For comparison, we took two screws 6x90 and 4.5x70, two self-tapping screws 4.8x110 and 3.5x55, as well as a small nail 3x75.
A short video will help you see the difference between them.
It can be seen that hardened screws are the most fragile and break almost immediately. Black steel screws are more durable, but also cannot withstand several bends. But to break a nail, you need to make a couple of dozen sharp bending movements.
This test does not mean that we are advocating the use of nails. We just want to show that the choice of fasteners should be treated with due care. And, of course, there are plenty of places where self-tapping screws will give a head start to any nails.
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. On a concrete foundation under bottom trim lay the so-called beds - boards. 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 deeper into the thickness 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 a traditional 2.5-3 m frame wall on a concrete base, the depth of lowering the anchor into the 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 a concrete slab or strip in specified places, hollow cones with internal threads are inserted into the thickness of unhardened concrete. 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 connection.
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 the horizontal level are allowed in dimensions of 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 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 make 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. Either through the use of metal with large thickness sections, 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 with outside 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 to a 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?
During construction in regions with cold climates, non-solid material is used as vertical posts. wooden beam, and assemble a corner post 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 purpose single racks are used, but the load from window and doorways removed using a bolt. 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
To nodes 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 the rafter beam and to the ridge.
- 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 secure 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 jibs, to withstand the wind it is necessary to use rigid slabs in the outer cladding.
- Use as corner posts solid timber or boards placed tightly next to each other. 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 – new technology, in which, despite its apparent simplicity, there are many nuances and features.
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”. With a larger number of 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, heavy expenses for heating, 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 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 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 fasteners. 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.
Misuse 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 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. Use of perforated steel fasteners without ligation wooden elements do not always guarantee the design strength of the frame.
It is unacceptable to fasten fastening elements of beams and other elements of the load-bearing frame 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 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. Minimum diameter 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 the assembly of walls “on site”, mixing the technology of building a frame house with half-timbered technology or “posts and beams” with the installation of floors in last resort, which is fraught with the need to insert or “hang” floor beams, the need to move on temporary flooring, with a high probability of getting injured 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 with a diameter of up to 40 mm can be drilled in any part of the I-beam with the exception of the support 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 more thin sheets 8 mm thick. 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 sheathing must be left with gaps on thermal expansion 2-3 mm in size. 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 internal partitions To external walls according to standard schemes connection devices of clause 7.2.12 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 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 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, ventilation valves must be installed in each room, 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.
The importance of choosing the right fasteners when constructing a frame building is beyond doubt. In this case, when connecting different elements and parts of a building, the type of hardware suitable for a particular situation should be used. Of course, in most buildings built using frame technology, the main type of fasteners are nails.
Types of fasteners used in frame house construction
In today's frame housing construction apply the following types fasteners:
- Nails. Traditional option devices of various nodes wooden houses. It is a wedge driven into wood. They are used to connect almost all elements and parts of a frame house, with rare exceptions;
- Self-tapping screws. They are immersed in the material by screwing, which is accessible due to the presence of a screw thread. The main place of use is sheathing and cladding;
- Staples. Partially driven into wood or other materials. They are used mainly for cladding frame houses;
- Hairpins. They are a bolted connection. They are made of galvanized steel and are used for fastening beams, rafters and other most massive and critical load-bearing structures.
The above list shows that only nails are used at any stage of the construction of a frame house. This is explained by the presence of a number of significant advantages of this type of fastener.
Advantages of nails over self-tapping screws
The main advantages of nails compared to self-tapping screws with similar parameters are as follows:
- A stable position of the nail inside the wood, which is achieved by pressure exerted on the fastener from all sides;
- The ability to withstand constant temperature and humidity deformations characteristic of wood, which destroy the screw threads of self-tapping screws and make their position in the material unstable;
- The ability to withstand severe lateral loads, characteristic of hinged joints of frame houses and easily breaking self-tapping screws made of red-hot iron.
As a result, it is advisable to use self-tapping screws in frame house construction only in units where the main load is the pull-off effect, for example, when installing sheathing, fastening mineral wool, chipboard or siding.
Types of nails and their functional purpose
The nails used in today's frame construction are high-tech hardware of several types. The most commonly used:
- Galvanized regular and screw (another name is rough, ring). The use of this type of fastener is a mandatory requirement when constructing external structures of a building. Screw, ring or rough nails are equipped with a special notch various shapes, increasing friction in the nodes and, as a result, the rigidity of the frame;
- Black regular and screw. They are used to connect individual elements and structures located inside the building. The use of non-galvanized nails is a way to save money during construction, however, not all professional builders use this option in practice;
- Nails for nailers. They are special hardware that is immersed in wood using special tool no shock load;
- Tar paper nails, black and galvanized. They are small in size and used for cladding various slabs or fastening rolled insulating materials.
The number of types of nails used in frame construction is not limited to the above list. Moreover, modern manufacturers regularly present various improvements to this seemingly simple and common fastening hardware.