No wonder people associate a house with a fortress. The building must have high reliability indicators in order to stand for several decades, or even more. Building a house is not particularly difficult, especially in our time, when modern technologies are at the disposal of people. But keeping it in its original form is already a more serious matter. At the same time, a significant role is played by the casing box in wooden houses.
Of course, building private real estate with other, much more durable materials has more advantages. However, wood has a special magic, because there are still admirers of the good old Russian construction technology.
Features of house shrinkage
Shrinkage is typical for any wooden building, which is due to the natural property of wood to dry out due to a decrease in moisture levels. In a slightly different way, this is called shrinkage. This process can be influenced by a number of factors, including the following:
- originalsizes of building materials;
- species of wood used;
- wood processing technology (in particular drying);
- building operating conditions;
- dimensions of the house;
- building season (winter or summer);
- construction technology;
- experience of specialists, and, accordingly, the quality of assembly at home.
The need for a casing in the house is also due to the fact that different wood shrinks differently. That is, based on the height of the house, buildings shrink by 1 meter:
- from logs ≈ 150 mm;
- from timber (planed and unplaned) ≈ 60 mm;
- from profiled timber ≈ 40 mm;
- from glued laminated timber ≈ 20 mm.
More accurate data is contained in regulatory documents, but it is worth considering that theoretical information may differ from practical indicators.
What is a casing box?
Such a necessary element is otherwise called a pigtail, or, in a popular way, a casing. In fact, this is a wooden box that is placed in window or wooden openings before windows or doors are installed. The whole structure consists of several components, which include tops, risers and a window sill.
At the same time, there are some features in the manufacture of the casing box:
- The width of all elements must not exceed 260 mm. Otherwise, the entire structure will be covered with cracks.
- Wood moisture is also importantand should be at least 7-9%. Otherwise, cracks cannot be avoided either.
- Simple casing is needed for simple wooden windows, for plastic structures a complicated support with a gun carriage is required.
At the same time, the pigtail for windows and doors can be of different shapes. That is, in addition to the standard rectangle, it can be a trapezoid, a polygon, or it can be made in the form of balcony blocks.
Necessary in the box
Do you really need a casing or can you do without it? Here it is important, first of all, to take into account the fact that the shrinkage of a wooden house does not occur in one day or even a month. As a rule, it takes 2.5 years. And often in the first year the building will sit down by only 20%, and the remaining 80% will fall on the next year and a half.
The importance of casings for wooden houses cannot be underestimated, since some undesirable processes occur due to shrinkage. In particular, the inevitable cracking of logs, the disks begin to shift. In the absence of a pigtail, the top logs will press against the window or door frames with force, which will lead to distortions. As a result, windows and doors may stop opening altogether. It also adversely affects the wall cladding, which leads to the formation of cracks.
Ultimately, this can lead to more than just looking bad. The entire building, if no action is taken, can literally fall apart completely.
That's why casing is needed, which is a good protection for windows and doors fromdistortions. In addition, its service life is usually unlimited.
What is a pigtail?
According to the manufacturing technique, the casing box can be of several types:
- Set-glue.
- In the form of a pine tree.
- Combined version.
For typesetting-adhesive pigtails, edged material with a moisture level of 7-9% is used, which is still acceptable. Without fail, all existing defects are cut out, whether it be resin pockets, knots and other varieties. After that, the material is spliced along the length and width by means of a special adhesive composition. Finally, it is machined and polished.
For the pine variant, first a round tree trunk is sawn, and the resulting gun carriage is dried to a moisture content of 10-12%. At the next stage, trimming into blanks of the required dimensions takes place. Finally, the finished product undergoes special processing using a machine to form the required profile.
In combined casing, the risers and the top can be made of solid pine. While the type-setting and glue technology is suitable for the window sill. This option for installing a casing box is only suitable when it is not planned to carry out interior window decoration in the future.
Self-made casing
There is nothing complicated in the technology of making pigtails, and any owner is able to cope with such work on their own. All it takes is some knowledge ofregarding the products themselves. Also, you simply cannot do without a number of tools.
When preparing the necessary materials, you should also take care of personal safety - we are talking about a protective mask with a respirator. And with these assistants, the whole process will be greatly simplified and accelerated:
- drill;
- screwdriver;
- wood sander;
- saw (circular or gasoline);
- jigsaw;
- drills;
- measuring tools.
Any homeowner keeps them close at hand as they are stored nearby.
Box for plastic window openings
Many owners of private real estate, thinking about installing casing boxes, choose mainly plastic windows. In this case, preliminary preparation is indispensable.
First of all, you need to understand that the dimensions of the frame must be 15 cm smaller than the window opening. You also need to make a carriage with a groove in the end part of the opening and cut out a comb, which will be the base. Due to this, during the shrinkage of the house, the wood will settle along the grooves directly in the carriage, which will avoid a lot of pressure on the windows.
The carriage is made of a wooden bar measuring 100 x 150 mm, and a groove must be made in its center, inside which a comb is placed. The upper part of the pigtail is made of boards 40 x 150 mm, on both sides of which you also need to make grooves for the comb.
After that, the upper part of the casing is located on the ridgewindow opening. And when the side carriages are installed, the crossbar is fixed with self-tapping screws. Only here care must be taken not to allow the screw to accidentally fall on the comb. Otherwise, hard adhesion may occur and the functionality of the window casing in a wooden house will be impaired.
At the end of all work, it is necessary to process the gaps with tow or any other insulation. And the grooved combs need to be caulked.
Box for wooden window openings
If wooden structures are placed in the window openings, then everything is not so difficult here. Only first on the surface of the walls that will be adjacent to the window frame, you need to make grooves. Subsequently, casing beams will be installed in them.
To begin with, the lower beam of the pigtail is placed, which will avoid displacement of the side elements. And before installing them, you need to lay an interventional sealant. For this purpose, you can use jute or linen tow.
The upper casing element is placed last. A shrink gap should be made above it, which is also filled with jute or tow. Such a consistent assembly will provide windows with good protection against deformation during shrinkage of the house.
Box for doorways
In essence, a door frame is almost identical to a window frame, except for some minor differences. Only here there is one important point: the installation of the door frame should be carried out only after a year, and preferably 2 yearsafter building a house. During this time, the main period of shrinkage should pass.
Everything else is done the same way. That is, if a wooden door is placed, then grooves must be made in the side surfaces of the opening. And for plastic or metal structures, it is necessary to make a comb, on which a box with grooves is already installed. During the shrinkage of a wooden house, the comb will be inside the groove.
Additional fasteners are not required to install the door frame. Only between the opening and the box should lay the material to ensure heat and sound insulation. This can be done with both tow and jute.
Public opinion
On the Internet, you can find different reviews regarding casing. Someone asks about whether it is necessary to maintain the due date after the construction of the house (1-2 years). Some in response advise putting the pigtail right away, which is confirmed by many builders.
There is also an opinion that a window block can be installed without a casing box. However, hacks or incompetent "specialists" think so. But a pigtail is a necessary measure, and the vast majority of owners of wooden houses think so!
