Is it possible to build an attic on an old house? Houses with attics structure
It is not uncommon for a situation when, for one reason or another, a house that until recently seemed quite comfortable becomes cramped, or the dacha needs to be turned into permanent residence, while simultaneously increasing the area. Also, often the need for major reconstruction and expansion arises when purchasing a house with “experience”. You can get an increase in square footage in two ways - by adding a room or building on it. For many, adding a residential attic floor is a more preferable option, since there is no need to additionally fill the foundation, and there is not always enough space on the site for an extension. And among portal craftsmen, the addition of an attic floor is quite popular, and in this article they share the experience gained with those who are just deciding what to do and what to do.
- What is an attic in a house?
- Features of the construction of the attic floor during reconstruction.
- Experience of portal participants.
What is an attic at home?
By definition, an attic is a residential or non-residential premises in the attic space. However, in practice, only cold attics remain non-residential, and the attic is residential ( all year round or seasonally) space under an insulated roof of a special configuration. Unlike a full second floor, part of the walls in the attic is formed by roof slopes, which somewhat limits its functionality. Attic floors have always been popular, have not lost it to this day and are unlikely to lose it in the future.
Modern technologies make it possible to organize premises for any purpose in attics, as well as in full second floors - these can be bedrooms, offices, children's rooms or guest rooms. Today it is not a problem to place a full bathroom in the attic if necessary, not to mention a bathroom with a shower. Kitchens in attic rooms are a rather rare phenomenon; they mainly appear in cases where two families live and have a separate entrance from the street.
Perhaps the main condition for a comfortable existence under a roof is a height of 2.5 meters at the central point.
The permissible minimum for the attic floor is sanitary standards– 2.3 meters, although in practice other sizes are also found.
Features of the attic superstructure
Whether to build an attic is decided based on two factors:
- availability of technical capabilities;
- expediency.
The main question is whether the walls of a worn-out house will withstand the weight of the proposed structure, even if we are talking about the lightest, frame version. Therefore, the first thing you should do is make a plan and make a rough calculation bearing capacity walls and foundation. It’s not so much the type that will play a role here. wall material, how much is the condition of the walls. Other log houses with half a century of history are much stronger than those of “youthful” stone buildings.
The feasibility of such a global reconstruction depends on the dimensions of the house - if it is too compact, then the residential attic, taking into account the design features, will turn out to be tiny. If the width of the house is less than five meters, then a structure such as attic floor, it’s pointless to build on it. However, despite all the restrictions, sometimes a small interesting attic room It’s better than nothing, the main thing is that the walls can hold up and your wallet can handle it.
But even if the walls are strong, the multiply increased load must be evenly distributed, for which an armored belt is poured around the perimeter of the stone base.
When pouring the armored belt, fasteners for the Mauerlat (studs) are immediately placed into it, which will firmly fix the entire structure in place.
Without sufficient insulation, it is impossible to build an attic even for seasonal stay, since without insulation in the summer there will be a steam room in the attic. The attic in a residential building is insulated along the entire perimeter to form a closed loop - ceilings, inclined and vertical walls, gables. Today, insulation can be anything from typical slabs, rolls and mats to blow-in, fill-in and spray-on. However, regardless of the type, its thickness must be sufficient to ensure the standard thermal resistance coefficient of the wall (tabular data by region).
If we are talking about mineral slab heat insulators, which are used most often, then for most regions 150-200 mm is sufficient. It is more efficient to lay this thickness in several layers with overlapping seams to minimize heat leakage. Since the attic is a heated room, great importance is given to the construction of a vapor barrier so that warm air did not provoke condensation in the insulation or roofing pie.
For the free removal of moisture, which, despite all the barriers, will accumulate between the insulation and the roofing of the attic floor, a ventilation gap of at least 5 cm is required, and ideally a ridge aerator.
The simplest option is vertical window, installed in the gables, but for proper lighting, special ones are also needed, skylights, mounted directly into the roof.
The number of windows is calculated based on the permissible minimum - for every 10 m² of area 1 m² of glass.
If the plans include skylights, then during assembly rafter system It is worth calculating the pitch of the rafters according to their dimensions, taking into account the seam.
In most cases, frame and timber attics are built on, since they are lighter, cheaper, and construction process faster. Considering that the house is residential, the sooner it is under the roof again after dismantling the old one, the better. If they choose a more capital, stone option, then they give preference to lightweight materials (gas block, foam block, expanded clay concrete).
Experience of portal participants
Major reconstruction of the house of one of our craftsmen with the nickname Soboleff was subjected to twice - first, it was turned from a summer cottage into permanent residence, and then an attic room was built on. Comment from our user:
Soboleff
The long-awaited warmth has arrived, and with it the beginning of the realization of an old dream - replacing the old roof with an attic. All winter we were busy with calculations, drawing a plan, designing in “ketchup”, saving money. I think this report will be of interest to those who have a house that is not very large in size, quite old and built from what was there. In my case it's my ex summer cuisine, 30 years ago converted into a residential building with an area of about 60 m².
The development of amenities and active changes in the layout in order to increase the level of comfort have been carried out over the past few years.
Walls made of sand-lime brick They were put together somehow, the foundation also touched the technology sideways, so the craftsman decided not to take risks and make a frame superstructure. The height of the building walls is 1200 mm, from the finished floor to the ridge – 3500 mm, gable roof with a corresponding pie, metal tiles as a roofing covering. According to the layout on the attic floor there are a couple of children's rooms of 16 square meters each, common corridor, a bathroom above the existing ground floor and a low storage room.
Attic floor, layout.
Dismantling revealed sagging, rotten beams and the deplorable state of the masonry in the upper rows; not only these rows were replaced, but also wooden beams above window openings to the corner.
The perimeter lined with brick was filled with sheathing, reinforcement was laid, pins were inserted to secure the mauerlat, and an armored belt was poured.
Secondly, the internal partitions were brought up to the level of the external walls, the floor beams were laid, the subfloor was hemmed, and the frame assembly began. All wooden materials pre-treated with fire bioprotection.
The role of the jibs to impart rigidity is assigned to the slab sheathing - OSB 3, all joints of the slabs and the frame were foamed. The thickness of the stone wool insulation on the ceiling is 200 mm, on the walls - 150 mm, plus another 50 mm further along the perimeter of the entire facade.
For ventilation, a “cold triangle” was left at the very top. The craftsman applied four overlapping layers of insulation along this flat area of the ceiling. A roofing “pie” according to all the rules – with waterproofing, wind protection and counter-lattice.
On the walls attic room outside, they also filled a counter-lattice from a 50 mm bar with a pitch under the insulation sheet, laid the slabs, and covered the contour with a wind barrier. The slabs were fixed to the house using hangers and plastic disc dowels. On top of the wind protection is a galvanized profile 60x27 mm, creating a ventilation gap and a subsystem for siding.
Hello! Please tell me. We have an old house G figurative form half a brick, the inside is insulated with adobe, the foundation under it is 30-35 cm strip to the ground, then the base is made of brick. The foundation for the extension was poured to make the house look right rectangular shape size 6.7x10. We want to completely remove old roof with a ceiling to raise the ceiling height and build an attic of 2 rooms under a gable roof. We are afraid that the walls and foundation will not hold up, how can we transfer the weight of the attic.
We thought about placing channel support beams around the perimeter of the old house close to the walls of the old house. and all the weight new roof transfer the new extension to them. What's the best way to do this?
Tatyana, Novoaleksandrovsk, Stavropol Territory.
Hello. Tatyana from Novoaleksandrovsk!
Yes, such an option for redistributing the load from the weight of the roof (and from the new attic that you are going to install) exists. If old foundation and the half-brick walls are not sufficient to support the newly erected attic and the roof above it. And judging by the characteristics you provided, it is so.
Support beams made of channel, as an option - from I-beam, round or profile pipe. If you make it from a channel, then preferably size no less than No. 16.
Although the design workshop can calculate for you a more accurate cross-section of supports. But to do this, you need to provide them with the entire list of materials from which you are going to make the attic and roof, as well as all their parameters. And the project can cost several tens of thousands of rubles, depending on the number of its sheets and the volume of the explanatory note.
And if we speak offhand, then approximately you will need to place the supports about a couple of meters from each other. With their deepening into the ground, also about a couple of meters, with concreting. Along the top of the supports, place a strapping from the same channel with its welding.
In addition, it is necessary to install at least two transverse beams, which will simultaneously serve as connections between the opposite walls of the house and as the base of the attic floor and elements of the rafter system.
It should be said right away that the cost of these supports and additional elements will be decent. Since one linear meter channel No. 16 is estimated at different regions from 400 to 500 rubles. And how many of these meters you will need, calculate for yourself.
If you have never encountered such construction, then you should invite a knowledgeable builder so as not to mess up and then redo it. Remembering that life is most precious, and unreliable construction can threaten it.
That's all in a nutshell. Good luck!
Other questions on the topic of attics.
In order to build an attic above the house, you first need to make sure of the reliability of the structure, which will bear almost the entire load of the structure being built on. If it is not strong enough, then it is necessary to install columns on the foundation. They will be the supporting structure for the constructed attic.
Please note that the structure that bears the entire load of the structure being built on must not be damaged. If it is not, then its frame should be replaced with a more reliable one. In this case, part of the load of the attic will be borne by the walls.
The strapping belt is an integral element of such construction work. It distributes the load of the attic onto the house being restored by combining their walls together.
Such a belt is made mainly from reinforced concrete, but expanded clay concrete structures are also found.
To build an attic above a multi-storey private house, it is recommended to use metal carcass, it is more reliable. It is necessary that the ceiling between the house and the attic be solid.
Load-bearing structure of an attic in a private house
The attic and attic of a house are very similar in design. When constructing a superstructure, it is necessary to take into account all weather conditions of the area in which the house is located. The floor being built on must withstand the wind and the pressure of the snow layer.
To build an attic, it is best to use the most durable materials. These are metal, wood or galvanized profile. If desired, you can use any combination of the above materials.
It should be noted that wood is best used where there is no electricity, since welding in such structures is difficult. Before working with wood, it must be antipyretic. This is fire protection for wood, it is needed in order to this material did not ignite in extreme situations.
A variety of frames, columns and rafters are load-bearing structures. They are attached along the perimeter of the outer wall.
It is best to choose lightweight materials for the load-bearing structure, as they can be assembled using bolts and rivets without using welding. These are wood or galvanized profiles.
In order to have an idea of how to build an attic, it is recommended to watch the video tutorial in the next tab.
Insulation pie in the attic floor superstructure
When building an attic structure, it is necessary to responsibly choose the material with which the superstructure is insulated.
There is no thermal cushion in the attic floor, so the room loses about 25% of heat.
Probably the most The best way increase usable area of your own home is to replace the gable roof of the house with a mansard one. This way you can buy one, two or even three additional rooms without cutting out extra space on the site and without dealing with the very labor-intensive processes of pouring a new foundation and erecting walls. And to find out how to make an attic correctly, you need to consider all the stages of its arrangement, starting with calculations and ending with roof covering and finishing of the resulting additional rooms.
In order for all the work to be successful, first of all you need to make sure that the existing walls (if the superstructure is being built in an old house) are able to withstand the additional load. This factor will determine whether such a construction project is worth undertaking, and if so, which attic roof design would be best to choose.
It should be noted that the load on load-bearing walls will increase significantly - due to a larger number of rafters, due to the mass of interior decoration of walls and floors, windows and doors, insulation systems, as well as all elements of the interior filling of attic rooms. All of these factors indicate that you need to start with a choice optimal design attic, with calculations, design and drawings of the future superstructure.
Types of attic superstructures
According to current building codes, an attic is considered to be a room under a roof that has a height from the ceiling to the ridge of at least 2500 mm. If this parameter is less than the specified limit, then the room is considered an ordinary attic.
- If the vertical posts that determine the height of the walls of the room are 1500 mm in size, then the attic space can be considered a full floor.
- A semi-attic is an attic space in which there are no vertical posts at all, or if they have a height of 500 to 700 mm.
The basis of any roof structure is always triangles with their “rigid” structure There are several types of attic superstructures, but the most popular of them are high gable and broken structures. Their popularity can be explained more simple calculations, relatively simple installation work and ease of use. In third place, after gable and broken structures, we can name a single-pitch roof option, which is also sometimes used for arranging an attic. Unfortunately, not every house design can use this type of superstructure, since it requires not only reconstruction of the roof, but also raising the already built walls, which significantly increases the load on both them and the foundation.
If it is being built new house, and the second floor is planned in the form of an attic, then a pitched roof option is well suited for this purpose. In addition, this will help save on roofing material.
More complex structures - domed, hipped, and also with various cantilever projections arranged in the roof slopes (single-level and multi-level) are used extremely rarely and only in exclusive projects, since they have a complex design both in engineering calculations and in installation.
The figure below the numbers shows:
1 – Gable attic.
2 – Broken attic
3 – Single-level cantilever attic
4 – Multi-level attic.
Gable attic
Attic space under d a vuskat roof, which is arranged at an angle between the slopes of 80 ÷ 90 degrees at the ridge, can easily be converted into an attic. To create full-fledged residential premises under it, it will be necessary to carry out a number of necessary reconstructions, for example, very often it cannot be done without strengthening attic floor. All these alterations, plus the necessary insulation, will certainly “eat up” a significant part of the usable space under the roof, so you should not expect that the rooms in such an attic will be spacious and with high ceilings.
Of course, if the dimensions (length and width) of the house are large enough, and the roof has a significant angle of inclination (45 degrees or even higher), then after the alterations you can count on a relatively spacious attic space.
broken roof
The room under the sloping attic roof will be much more spacious and with enough high ceiling. Such an attic can be easily divided into two separate rooms.
Interior of an attic made according to the “broken” type The sloping roof has four planes of slopes. They are placed at different angles - the upper slopes are called ridge slopes, and the lower ones are called side slopes. They, for the most part, act as walls.
This type of mansard roof is somewhat more difficult to design and install, but the result will delight you with spacious rooms and a respectable appearance Houses.
Single-level cantilever attic
This type of attic has an even more complex design than the previous one, as it involves displacement attic space one way or the other.
Using this option for installing an attic, you can get spacious rooms, much larger in area than under a pitched roof.
The design of a single-level attic roof can replicate not only a gable, but also a single-slope version - this will depend on how much it is planned to move the console out of the attic and raise its ceiling.
Multi-level add-on
Multi-level construction is the most difficult to design and install. Help will definitely be needed in its development and construction qualified specialists. The supports for the levels of the attic rooms are various rafter systems and ceilings, which are combined with the main one. A multi-level system involves the arrangement of rooms at different levels attic space, which is why the consoles should be located this way.
Having chosen the most desirable type of attic, you need to determine whether it is possible to install it on the old walls of the house, or whether they will have to be strengthened. Therefore it is necessary to carry out accurate calculations and draw up a project.
Roof truss basics
Most roofs, and attic roofs are no exception, have one of two types of rafter systems, or a combination of them. Each of these varieties has its own characteristics, which depend on the location of the load-bearing walls of the building.
Hanging system
A hanging rafter system is defined by the fact that it is supported only by two external main walls located along the length of the building, in which there are no internal main partitions.
Such a system is used provided that the distance between the main supports is no more than 13 ÷ 14 meters. In any case, this design puts a fairly large load on the walls and foundation of the building.
To weaken the loads in this system, various support structures are used. elements - crossbars, headstocks, struts, tightening, racks and other parts.
For example, the headstocks seem to hang the entire system to the ridge beam, and the struts pull the ceiling beams to the rafters.
For the attic floor in this system, it is necessary to use thick bars, logs or boards that are installed on the edge. Their thickness can be determined from the table given in this publication, taking as a basis the distance between the support points.
In order for the ceiling to be reliable and durable when using a hanging system, you need to make accurate calculations, and if it is difficult to do this yourself, then it is better
Layered design
The layered system is distinguished by the fact that it has supports not only on external main walls, but also on internal partitions that have a foundation underneath them.
Therefore, when starting the construction of a house in which an attic is planned, you need to think in advance about the location of the internal capital partitions.
For a house with an attic, a layered system is the best option, since the beams covering the house will be firmly and securely fixed to the walls and partitions.
When constructing a broken attic roof structure, you can use combined option rafter system, that is, use elements of both hanging and layered systems.
Attic design
When drawing up a project for the construction of any type of attic, it is recommended to consider it in different projections in order to clearly determine the location of all supporting elements. When calculating all the parameters of the attic, they must be immediately included in the project.
Based on the calculations made, the locations and methods of installation of all structural elements of the rafter system are determined. Calculation is also necessary for precise definition materials needed for the construction of the attic and their parameters.
Design elements
Any of wooden structures The attic roof consists of certain elements that are connected to each other by connecting nodes having different configurations. To better understand the design of these connections, it is recommended to draw each of them, and when making installation work- Be sure to have this drawing on hand.
The design of a sloping mansard roof includes the following components of the system:
- Mauerlat - element, made from wooden beam and laid on the main walls of the building in its length. It serves to evenly distribute the load from the rafter system structure onto the wall and foundation. Rafter legs are installed and secured to the Mauerlat. This element is mounted both in a gable and in a sloping attic roof structure.
- Floor beams, which are laid on the main walls of the building and form the basis for the future attic floor and the ceiling of the first floor, as well as for the installation of the entire rafter system.
- The rafter leg consists of one straight element - bar or boards in a gable roof, or from two parts - in a broken structure. In a sloping mansard roof top part, attached to the ridge, is called the ridge, and the lower one, which forms the walls of the attic, is called the side. Obviously, the side leg will be installed according to the layered principle, while the upper ridge rafter- usually becomes droopy
- For the ridge, a beam or board of a certain thickness is used. Sometimes they do without this by connecting the upper ridge parts of the rafter legs, which form the ridge.
- Racks are the supporting elements of the system. They support the rafter legs and relieve some of the load from the walls and foundation of the building. The racks will later become the sheathing for the walls, which will be installed during the finishing of the attic.
- Bevels or other elements installed diagonally are additional supports that fasten the rafters and supporting beams, making the design of the system more reliable.
- Between the rafter legs, for rigidity, bars are installed, called inter-rafter purlins - they also give rigidity to the system.
Carrying out basic calculations of the attic
It is quite difficult to independently develop a mansard roof project, since this process requires certain knowledge and skills in designing and carrying out specific architectural calculations. If you make mistakes, the attic structure will be unreliable, and in addition, its weight can damage the walls and foundation of the building.
Everything must be taken into account in the calculations - from the beginning of construction to the finishing of the premises. However, if the design is not too complex, then you can try to cope on your own.
Calculation of ridge height
Size usable area attic space depends on the height of the roof ridge, and the latter is determined by the selected slope of the slopes - the smaller this angle, the lower the ceiling and, accordingly, the smaller effective area attic space.
N=L× tgα
N— ridge height;
L- ½ the width of the building (if we are talking about a gable symmetrical roof);
α - angle of inclination of the rafter system slope.
Diagram - for clarity As an example, you can substitute the data used in the formula above:
Building size 8×10 m, slope angle 30°, tangent 30°= 0.58
H = 8/2 × 0.58 = 2.32 m
The height of the ridge will be equal to 2,32 m.
Very detailed, with everyone possible nuances and the necessary reference tables, the process and all other related parameters are outlined in a separate publication devoted specifically to this issue.
Attic interior space area
The technique used to determine the area of the attic space will make it possible to calculate the amount required material for the construction of a rafter system, for insulation and finishing. Particularly accurate calculations are important if the attic will be used for arranging additional living rooms, since they require special design.
Usually the entire area of the room under the roof is calculated, that is, both useful and the so-called "deaf". The living space is limited by installed racks, which will be the basis for the installation and finishing material of the walls. The area behind them is considered deaf, that is, most often not used.
The total area is calculated quite simply: the width of the overhangs on both sides is added to the width of the building. The resulting amount is multiplied by the length of the building.
The area of the living space is also easy to find: to do this, you need to measure the width of the attic space between the racks installed under one and the other roof slope, and multiply the resulting parameter by the length of the attic from gable to gable.
Roofing area
To determine in advance the amount of roofing material, you need to calculate total area roof slopes.
If you decide to install a broken or even more complex structure, you need to calculate the area of all sections of the roof. To do this, you need to divide it into separate geometric shapes, and then calculate the area of each of them and add up the results.
For those who do not clearly remember the formulas for calculating areas flat figures, a diagram is provided - a “cheat sheet”.
Shed roof area
If the attic roof is pitched, then its area can be calculated using the formula: Sabcd = Lcd × Lbd.
The area of one slope - nothing could be simpler Pay attention to the picture. When calculating, not only the length and width of the rafter structure of the slope are taken into account - we must not forget about the eaves overhangs on all sides.
Gable roof
With a symmetrical arrangement of roof slopes, to calculate a gable roof, all that remains is to multiply the value obtained above by two.
For example, let's take the same example discussed above. The size of the building is 10×8 m. The angle of the slope is 30°, the height of the ridge H = 2.32 m. It is easy to determine the length of the rafters - S
S = Н / sin α = 2.32 / 0.5 = 4.64 m
We accept cornice overhang 0,7 m, gable overhang 0,7 m. Using the formula for a pitched roof, the area of one slope is calculated.
(10 + 2×0.7) × (4.64 + 0.7) = 60.88 m²
Then, to get the total area of the two slopes, the resulting result is multiplied by two.
Q = 121.76 m²
This technique is intended for calculating the continuous surface of slopes, without taking into account windows, ventilation ducts and chimneys.
If the roof has a very complex structure, then it is better not to take risks and still seek help from professionals who will make the necessary calculations using special computer applications.
When using slate, soft roofing, and other profile materials, you can use a simplified calculation formula.
Let's start from the picture:
So, the following formula is applicable for calculation:
Q= K × (B + 2A) × (L+2C)
Q— required amount roofing;
IN — width of the building (along the gable wall);
A— the width of the planned roof eaves;
L- total length of the building;
C- width of the side overhangs of the roof.
TO is a coefficient that takes into account the angle of inclination of the slope relative to the horizon (α). By by and large, he is trigonometric function secant (sec), equal to the reciprocal of cosα.
In order not to go deep into theory, it’s easier to give a table of the coefficient TO in absolute, that is, numerical dimension:
| Tilt angle, degrees | Factor K | Tilt angle, degrees | Factor K | Tilt angle, degrees | Factor K | Tilt angle, degrees | Factor K |
|---|---|---|---|---|---|---|---|
| 1 | 1.0002 | 18 | 1.0515 | 36 | 1.2361 | 53 | 1.6616 |
| 2 | 1.0006 | 19 | 1.0576 | 37 | 1.2521 | 54 | 1.7013 |
| 3 | 1.0014 | 20 | 1.0642 | 38 | 1.2690 | 55 | 1.7434 |
| 4 | 1.0024 | 21 | 1.0711 | 39 | 1.2868 | 56 | 1.7883 |
| 5 | 1.0038 | 22 | 1.0785 | 40 | 1.3054 | 57 | 1.8361 |
| 6 | 1.0055 | 23 | 1.0864 | 41 | 1.3250 | 58 | 1.8871 |
| 7 | 1.0075 | 24 | 1.0946 | 42 | 1.3456 | 59 | 1.9416 |
| 8 | 1.0098 | 25 | 1.1034 | 43 | 1.3673 | 60 | 2.0000 |
| 9 | 1.0125 | 26 | 1.1126 | 44 | 1.3902 | 61 | 2.0627 |
| 10 | 1.0154 | 27 | 1.1223 | 45 | 1.4142 | 62 | 2.1301 |
| 11 | 1.0187 | 28 | 1.1326 | 46 | 1.4396 | 63 | 2.2027 |
| 12 | 1.0223 | 29 | 1.1434 | 47 | 1.4663 | 64 | 2.2812 |
| 13 | 1.0263 | 30 | 1.1547 | 48 | 1.4945 | 65 | 2.3662 |
| 14 | 1.0306 | 31 | 1.1666 | 49 | 1.5243 | 66 | 2.4586 |
| 15 | 1.0353 | 32 | 1.1792 | 50 | 1.5557 | 67 | 2.5593 |
| 16 | 1.0403 | 33 | 1.1924 | 51 | 1.5890 | 68 | 2.6695 |
| 17 | 1.0457 | 34 | 1.2062 | 52 | 1.6243 | 69 | 2.7904 |
| 35 | 1.2208 | 70 | 2.9238 |
Let's return to our example:
Q= 1.1547 × (8 + 2 × 0.7) × (10+2 × 0.7) = 123.74 m²
Taking into account overlaps slate sheets - the result is almost the same as in calculations carried out by another method. Of course, on advice experienced builders, to the resulting area when purchasing roofing material, another 10 ÷ 15 should be added %
(The picture shows gable roof However, the formula is fully suitable for calculations with the required level of accuracy for pitched or hip roofs. True, with a caveat - hip roof The steepness of the main and side slopes must match. If not, then the calculation is carried out for each pair of slopes separately, and then the value is summed).
Total weight of troping system and roofing
It is equally important to choose wisely optimal material for the roofing and correctly make the sheathing for it. This calculation is carried out taking into account the length of the rafters and their slope angle.
The lathing for roofing material can be sparse, mixed or solid. For example, metal tiles, corrugated sheets or slate are fixed to a sparse sheathing, and a soft roof - only to a solid one.
When choosing a roof, you need to get information about it operational characteristics. The durability and reliability of the roof structure will depend on them. Roofing material must also be selected taking into account the specific region and its climatic conditions, especially factors such as temperature changes and strong winds.
An important factor is the weight of the roofing, especially if the attic roof is installed on old walls. Therefore, you should estimate the weight of the roof in advance and find out how much the load on the building structure will increase, and whether it will be acceptable.
| Roofing material for attic roof | Roof slope | Material weight kg/m² |
|---|---|---|
| Asbestos cement slate sheets with medium profile | From 1:10 to 1:2 | 11 |
| Slate with reinforced profile | From 1:5 to 1:1 | 13 |
| Bituminous shingles | From 1:10 and more | 6 - 8 |
| Soft roofing with continuous sheathing | From 1:10 and more | 9 - 15 |
| Galvanized metal sheets with single folds | From 1:4 and more | 3 - 6,5 |
| Double folded | From 1:5 and more | 3 - 6,5 |
| Ceramic tiles | From 1:5 to 1:0.5 | 50 - 60 |
| Cement-sand tiles | From 1:5 to 1:0.5 | 45 - 70 |
| Metal tiles | From 1:5 and more | 5 - 7 |
| Ondulin | From 1:10 and more | 3 - 3,5 |
Most often, soft roofing or ondulin is used to cover attics, since these materials are among those that have the lightest weight and are easy to install.
For example, you can calculate the weight of 1 square meter roofs where ondulin is used for covering, taking into account the sheathing and insulation - sprayed polyurethane foam. To do this, you need to find the sum of the weight of each of the materials and multiply by a factor of 1.1 (this factor takes into account the overlap on adjacent sheets of roofing material).
- The weight of a flat sheathing, 20 mm thick (plywood or OSB) is 14 kg/m².
- Insulation – polyurethane foam, 100 mm thick, has an average weight of 3 kg/m²
- The average weight of ondulin is 3.3 kg/m²
We get in total:
(14 + 3 + 3.3) × 1.1=22.3kg/m²
To calculate the total weight load of the roof on the walls, you need to multiply the weight of one square meter by the area of the entire covering. In our example this will work:
M = 123.74 × 22.3 = 2751.82 kg.
A lot - almost 3 tons - only very light roof covering with lathing and also a very light type of insulation.
But this is not all! Effective on the roof snow loads V winter period, plus wind pressure, all year round. These parameters are also necessarily taken into account when calculating the necessary wooden structural elements of the rafter system and floor beams, and when taking into account the total load of the roof structure on the walls and foundation of the building.
— Then, the entire system is covered with a vapor barrier film, which is secured to the joists with staples.
— Boards or plywood sheets can be laid on top of it.
— Decorative covering is laid on them — it can be linoleum, laminate, parquet board and other materials.
Additional insulation can be created by laying electric cable or infrared heated floors under the decorative covering. It is better to read about these possibilities separately in the article dedicated to
- If the floor is mounted on floor beams, you will have to work from the side of the first floor.
— On the side of the lower room, boards are mounted on the floor beams. It is desirable that they be smooth; you can even use a floorboard for the subfloor.
— After that, a vapor barrier film is laid on these boards from the attic side, which will cover not only the subfloor, but also the floor beams.
— Another layer of vapor barrier is laid on top of it and attached to the beams.
- Then, logs are attached to this covering perpendicular to the beams.
— Another layer of insulation is mounted between the joists, it is better to choose mineral wool, since, when straightened, it fits tightly between the bars, leaving no voids.
— Then it should also be covered with a vapor barrier material.
If you decide to cover the floor with one of decorative coatings, then plywood sheets are laid on top of the logs, and then laminate, linoleum or other materials are laid on them. Again, nothing prevents you from using, for example, film floor heating in this case.
Installation of insulation on the walls and ceiling of the attic
Having finished installing the floor, you can proceed to installing the insulation on the walls.
— If material in mats is chosen for this process, then before laying it, sheets of vapor barrier material are fixed to the rafters.
It is fixed in such a way as to cover the entire space and deepen it between the rafters.
If the vapor barrier is fixed on the other side of the rafters, then the mats will independently adhere between two wooden surfaces.
— If one of the is selected, then there is no need to attach vapor barrier film. Waterproofing, which is laid on the rafters on the outside of the structure, will be sufficient.
Spraying polyurethane foam - quickly and efficiently, but requires special equipment and work skills To use this insulation technology, you must have a special technological equipment, or you will have to invite a specialist who will do the work in one day. It is not easy to carry out this operation on your own without experience - in order to complete the work without harming your health, you need to know the technology of the process and have the necessary protective equipment.
After the insulation work has been carried out, the walls are sheathed.
Prices for popular types of insulation
Insulation
Attic wall decoration
Before you start decorating the walls, you need to resolve the issue with electrical wiring, the cable of which must be well insulated using double-layer corrugated pipes.
After the wiring is done electric cable, you can safely begin installing the finishing material.
Usually used for finishing wooden lining, drywall or plywood with a beautiful textured pattern.
For any of the specified materials, preferably on rafter legs and vertical racks make a sheathing from slats with a cross-sectional size of approximately 20 × 70 mm. These guides are fixed in increments of 500 ÷ 600 mm. In addition to the fact that the sheathing of slats becomes the basis for attaching the finishing, it also forms a ventilation gap between the finishing material and the vapor barrier.
- made quite simply. It makes the walls smooth and neat, ready for painting, pasting with traditional wallpaper or even applying liquid wallpaper.
Therefore, plasterboard finishing should be chosen by those homeowners who like to frequently change interior design premises.
- Finishing walls with clapboard is a longer and more labor-intensive process than. For such cladding, a lathing with the above parameters is also perfect. The only thing you need to think about is the direction of the lining boards, that is, it should be located vertically when horizontal orientation lathing and vice versa.
If desired, after installation the wood can be varnished water based or give it a deeper color by using stain.
Wood is an amazing material that can create a special atmosphere in a room with the aroma of the forest, which has a positive effect on the structure and well-being of the residents. That is why natural lining is very often chosen for cladding the floor, walls and ceiling of the attic.
Video: insulating an attic space and finishing it with clapboard
- You can come up with a wonderful finish using plywood. But only if it will not be covered with paint on top, then you need to choose quality material, having a beautiful natural pattern. Plywood is installed much faster than lining, and makes the walls even, covering large surfaces at once.
This material can be covered with varnish, paint or any type of wallpaper, but you can leave the walls in their natural state, only by carefully cleaning out possible defects in the form of protruding splinters or burrs.
Building an attic is quite labor-intensive and difficult process, requiring high experience in the construction trade. If no one has any idea about the above-described technological operations, then you shouldn’t undertake it yourself - it’s better to invite professional craftsmen to carry out the work. They will get rid of unnecessary problems and will build the attic according to the project conceived by the owner of the house.
Video: example of construction and finishing of an attic
The attic allows you to significantly expand the usable area of the house. At the same time, the arrangement of the under-roof floor can be carried out even in an already finished building. At the same time, financial expenses will be relatively small, because basic necessary designs will already be present, and you can handle all the necessary activities on your own.
First of all, you must make sure that the foundation of the house can withstand the additional load from the attic floor. If necessary, the foundation must be strengthened or an attempt must be made to transfer new loads to a separate foundation. At this stage, you may need professional help.
Solve the issue of attic design. The under-roof floor can have a variety of shapes. In this case, the internal space of the room is determined by the features roofing structure.
The attic roof must be designed in a special way. You will have to get rid of the old rafters and related materials, replacing them with a new system designed taking into account the upcoming loads, angle of inclination and other important design features.
Thus, the rafter structure must be calculated and designed separately, specifically for your attic floor.
The most optimal roofing option for the attic floor is a broken gable roof. A gable roof will place a much greater load on the walls compared to single slope system. However, more convenient option You won’t find a roof for the attic floor.
At the same time, a broken roof will “eat up” the least amount of free space in the attic compared to all other types of roofs.
It is important that the gable roof has sufficient quantity load-bearing supports. Typically, layered rafters are used to construct such a roof. In this case, the elements of the rafter system must rest on load-bearing walls that can normally withstand incoming vertical and horizontal loads.
Before starting construction, decide what area the under-roof floor should have, whether you will insulate it and whether you need to install heating in the attic.
In accordance with your own preferences, draw up (order, find in open sources) an attic project with sketches, drawings, calculations and explanations.
The design documentation should reflect the following important features attics:
- the presence of additional partitions and load-bearing walls;
- number of window openings;
- features of the internal structure of the roof;
- type of roofing material, etc.
After this, calculate the required amount of materials for arranging the attic. It is best to make an attic using the same materials from which the structure itself is built (brick, blocks, etc.).
If you plan to use the attic exclusively for seasonal living, you can make it from more budget-friendly materials. Typically, wood is used in such situations. This material goes well with most existing building materials and is perfect for furnishing an attic.
Start setting up wooden frame– roof basics. Select suitable places for placing blocks needed for arranging partitions.
First you will need to lay out the exterior and gable walls. Proceed with the arrangement of the attic roof only after the construction of the house itself has been completed.
To assemble the frame, use a high-quality wooden beam measuring 15x5 cm. When performing each stage of the work, be guided by the sketches and drawings you have. It is impossible to explain everything solely in words.
First step
Strengthen the existing structure with slings. To strengthen the purlins, use special support blocks in the shape of the letter U. Blocks are installed and poured cement mortar. This strengthening will prevent further cracking of the walls.
Second step
Build solid gable walls and begin building the attic. After installing all necessary walls start installing the elements of the rafter system.
Third step
Install the rafters according to project documentation and make sure the installed system is reliable.
First you need to install the purlins, and only after that fix the rafters. First you need to lay out the stepped wall slopes, and then arrange the partitions of the attic floor. Be sure to make sure that the elements of the rafter system are evenly positioned.
Fourth step
Align the slopes of the gable walls using a band saw.
Fifth step
Nail batten boards to the rafters to install the insulating material. Secure the waterproofing, insulation and vapor barrier, and then lay another layer of boards on top of the waterproofing.
Sixth step
Apply your chosen finish to the sheathing. It is better that the finishing roofing material is as reliable and high quality as possible, so that the attic is cozy, warm and safe.
After completing work on the walls and roof of the attic, proceed to insulation and interior design under-roof room.
A wide variety of materials can be used to insulate the attic. For example, mineral wool insulation, expanded polystyrene, all kinds of blocks, etc. are very suitable for performing such work. One of the most preferred thermal insulation materials is fiberboard. Using this material as an example, the procedure for insulating an attic room will be considered.
In the case of using slabs with a thickness of 1.2 cm, the thermal insulation characteristics of such insulation will be similar to the properties of a wall laid in brick, or finishing made of boards about 5 cm thick.
In addition, the slabs have good noise insulation properties. Factory treatment with antiseptic preparations makes the material resistant to adverse external factors, and the relatively low price allows almost everyone to buy such slabs.
Most suitable material for attic insulation - fiberboard
On one side the slabs have a slightly corrugated texture, and on the other they are smooth. To cut slabs, you can use an ordinary sharp knife. The material is not particularly afraid of temperature and humidity changes. At the same time, work on thermal insulation of surfaces using fiberboard will not take much effort and time.
Finally on smooth side Fiberboard (smooth is the front) you can glue wallpaper or perform other finishing at your discretion.
Walls
Traditionally, thermal insulation work begins with insulating the walls. It is enough to fix the slabs with nails. First, duralumin plates should be placed under the fastener heads. Place the nails themselves staggered.
If the walls are not made of wood, you may need to use other fasteners. Focus on the situation.
To attach slabs to plastered surfaces, you can also use PVA glue or various kinds adhesive mastics.
Ceiling
At the stage of covering the ceiling, try to enlist the support of at least one assistant - the slabs have quite big size and attaching them alone is not particularly convenient.
The cladding is carried out according to an extremely simple scheme: the slab is carefully applied to the fastening point and fixed using T-supports made of boards, nails and duralumin plates. Wear safety glasses at this point.
The floor can be insulated using two methods.
In accordance with the first method, the surface is first covered double layer roofing material, after which the fiberboard is fixed on top, and then the finished floor is installed.
In accordance with the second option, fiberboard slabs are nailed to the floor, and carpet is glued on top of them. This coating is very convenient. For additional convenience It is recommended to impregnate it with a special composition that makes further maintenance of the carpet easier.
Before gluing the carpet, it must be unrolled and kept in the room for 7-10 days. Fibreboard boards pre-coated with glue. After gluing the fiberboard, you need to additionally press it to the surface using boards and leave to dry for a day.
In conclusion, all you have to do is carry out a number of works on the internal improvement of the attic. Start from the ceiling.
Ceiling
The best option– arrangement of a light suspended ceiling. Lining is well suited for the construction of such a structure. You can also use hardboard, plywood or other suitable materials.
It is more convenient to first make the ceiling to size, and then attach it to the crossbar of the truss.
Walls
Nail crossbars made of high-quality wooden beams to the rafter posts. Nail the chosen one to the frame finishing material. The best option is wooden lining.
Niches
In places where niches form (and they will definitely be present due to the peculiarities of the roofing structure), you can nail plasterboard or other suitable material, creating compact cabinets for storing various types of accessories.
Depending on the available space on the attic floor, you can arrange a bedroom, study, or children's room. Focus on the specifics of your situation.
Lighting
Consider the procedure for arranging the attic lighting. The best option– organization of local lighting for each corner of the room. This way the interior of the attic will be most expressive.
In matters of furnishing and further arrangement of the under-roof floor, be guided by your needs and capabilities.
Good luck!
Video - Do-it-yourself attic construction