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How to make a floor on the roof. Insulation of the attic floor. Why do you need to insulate your attic?

Are you insulating your house for winter and don’t know how to insulate the attic floor using wooden load-bearing beams? Having gained experience in this matter, I will definitely convey technical points thermal insulation, and I will also describe step by step the procedure for carrying out the work.

Why insulate the attic?

We must not forget that a significant part of heat loss occurs through the roof. Therefore, when constructing buildings with cold attics, it is very important to pay attention to proper thermal insulation of the ceiling between the heated room and the attic.

Below I will try to explain in an accessible language how attic insulation affects the internal microclimate and overall heat loss in the house:

Purpose of the attic. Any unused attic under a sloping roof is, in fact, a buffer technical floor between the street and the living space. Its purpose is to smooth out significant changes in air temperature inside the house and outside;
Temperature conditions. At any time of the year, during the day the air temperature inside the attic will be several degrees higher than outside. Thus, in winter there will almost always be negative temperatures, and on sunny summer days there will be intense heat;
Heat losses in winter. When the temperature of any substance increases, its density always decreases. Therefore, in heated rooms, heated air from household heating devices, always rises up to the ceiling. If the ceiling has insufficient thermal insulation, then during the cold season, all the heat from the room will go outside through the attic;

Excess heat in summer. On hot summer days this process will occur in reverse. The air in the attic will become very hot from the hot roof in the sun, and then transfer its heat through the uninsulated ceiling into the apartment.
Reverse air circulation. After touching an uninsulated ceiling, the heated air quickly cools down, and due to the increase in density, it sharply sinks down. Indoors, this leads to excessive reverse air circulation and the constant formation of drafts, which have an adverse effect on the health of residents;
High humidity. Upon contact of heated humid air with a cold, uninsulated ceiling, small drops of condensation may form under the ceiling. This will lead to an increase in air humidity in the house, and will also contribute to the appearance and development of mold on the walls and ceiling;

Economic factor. Confirmed heat loss through an uninsulated roof is at least 20-30%. This means that proper insulation of attic floors using wooden beams will save up to 30% of fuel during each heating season. Air conditioning in summer will also require lower costs;
Damage from a “warm” attic. Among other things, the penetration of warm air into an uninhabited attic, from time to time, can lead to unpleasant consequences:

As warm and cold air mixes, condensation will begin to form in the attic. Drops of water will settle on all surfaces, which will lead to rotting and destruction of the wooden supporting structures of the roof;
From the warmth of the attic, the snow masses on the roof slopes will gradually begin to melt. Thawed water will freeze as it flows down. This can lead to the formation of large icicles along the edges of the roof, as well as freezing of rain gutters and downspouts.

All the factors described are typical not only for residential buildings. They should be taken into account when designing and constructing any outbuildings on the site in which the heating system will be used (for example, a garage, bathhouse, barn, etc.).

Stage 1: Selecting insulation

When choosing materials for ceiling insulation, you should be guided by several criteria. In addition to low thermal conductivity, insulation attic floor must have the following qualities:

Moisture resistance and mechanical strength. The material should not be deformed or destroyed under the influence of mechanical load, and should not change its properties in the event of direct contact with water;
Heat resistance. The insulation must be absolutely non-flammable and should not be destroyed under the influence of high or low temperatures;

Light weight. In order not to create additional load on the load-bearing structures of the building, the thermal insulation of the attic floor should be quite light, so you need to choose insulation with a low specific gravity;
Vapor permeability. To ensure normal temperature and humidity conditions in residential premises, all finishing and Construction Materials must allow air and water vapor to pass freely;
Environmental Safety. Insulation for residential buildings must be hypoallergenic and chemically neutral. It should not contain harmful volatile compounds or toxic substances;
Lack of organic matter. I recommend using exclusively mineral or polymer based materials. They do not contain organic substances, therefore they are not susceptible to mold, and are not suitable for food for small rodents and pests.

Taking into account all these factors, several types of thermal insulation materials can be used to insulate attic floors:

Mineral wool. Produced in the form of rolls or rigid mats, from intertwined frozen fibers of molten sedimentary rocks. Mineral basalt wool is characterized by all of the above qualities, so it can be considered the most suitable material. Below I will give some recommendations for its use:

Basalt wool itself is very soft. To avoid pushing it through or denting it while walking, you need to lay plank flooring on top of it in the attic;
When choosing insulation, I advise you to give preference to rigid slabs that are covered on one side with aluminum foil;
They need to be mounted with aluminum foil inside the room. It simultaneously reflects heat and acts as a vapor barrier layer.

Glass wool. It has a similar manufacturing technology, only molten glass is used as the raw material for its production. I do not recommend using this material for insulating residential buildings for the following reasons:

Glass fibers are more fragile, so they can break under load;
The price of glass wool is much lower, but after creasing or getting wet, it partially loses its heat-insulating properties;
Small particles of glass penetrate deeply into a person's skin and cause severe irritation.

Expanded clay. This bulk insulation is produced in the form of small round pellets of light brown or red color. Expanded clay balls are formed as a result of sintering special varieties of red clay under high temperature conditions.

Expanded clay has the following characteristic qualities:

The internal structure of the material has many closed pores, so it has low thermal conductivity;
Each pellet is covered on the outside with a dense glassy layer of baked clay, so moisture practically does not penetrate inside it;
Small crumbly expanded clay pellets freely fill the entire volume, so they are convenient to use for insulating hidden cavities and hard-to-reach places in building structures;
Thanks to its mineral base, this material does not burn at all and does not emit harmful substances, is not susceptible to mold, and is not suitable for rodent food.

Styrofoam. This polymer thermal insulation material is made by hot molding from small round granules of polystyrene foam. It is usually produced in sheets measuring 1000x1000 mm, which can be from 10 to 150 mm thick. The following features are characteristic of polystyrene foam:

Of all existing species insulation, it has the lowest thermal conductivity;
The foam contains no organic substances, so it is absolutely not afraid of water, does not rot and does not contribute to the formation of mold;
By itself, polystyrene foam does not burn and does not support combustion, however, when exposed to high temperatures, it can emit toxic gases and acrid thick smoke;
Due to the polymer base and closed porous structure, foam sheets do not allow air and water vapor to pass through. For this reason, it is not very good to use for insulating living rooms and rooms with high humidity air.

Extruded polystyrene foam Abbreviated as EPPS. It has the same composition as polystyrene foam, but is made by hot extrusion from a molten mass of polystyrene foam. Specifications These two materials are also very similar, however, EPS still has some differences:

Expanded polystyrene has a porous, uniform structure and a higher specific density;
Due to this, it has higher thermal conductivity, but at the same time is more durable, and therefore is able to bear higher weight loads;
For this reason, I recommend using it for insulating unheated attics that will be used for storing seasonal items or household equipment.

Foil polyethylene foam. It is also called “Penofol” in another way. This roll material consists of thick polyethylene foam film, which is covered on one or both sides with a thin layer of aluminum foil. I recommend using it in combination with other types of insulation, because by itself it has specific properties:

The porous structure of polyethylene foam provides a low heat transfer coefficient, so it functions as an additional insulation;
Polyethylene film does not allow air, drops of moisture and water vapor to pass through at all, so Penofol can be used as waterproofing;
Mirror aluminum foil reflects infrared heat waves well. In other words, it does not allow radiant heat to pass through itself, and returns it back to the room.

Wood sawdust. This one is cheap and available material, is still often used to insulate ceilings in bathhouses, heated barns or small country houses. It is applied to the wooden floor from the attic side, in the form of a homogeneous thick mixture of sawdust and liquid clay mortar. Despite the seeming primitiveness of this method, it has its advantages and disadvantages:

Sawdust or small shavings can be bought inexpensively, or even taken for free, at almost any large sawmill;
There can be no problems with clay either, so such insulation is easy to prepare with your own hands in the required quantity at any time;
A mixture of sawdust and clay has a small specific gravity, and after hardening it becomes quite hard. Therefore, it does not place a significant load on the load-bearing beams, and allows you to walk on it with your feet;
Due to the mineral components, such a coating is permeable to air and steam, however, due to sawdust, mold may form on it, or mice may chew on it.

All mineral-based thermal insulation materials, to one degree or another, are capable of allowing water vapor and air to pass through. To protect such insulation from the formation of condensation or moisture penetration from the outside, they must be installed using a vapor-permeable waterproof membrane.

Stage 2: Preparation of materials and tools

In addition to insulation, for the work you will need lumber, waterproofing, as well as the usual set of carpentry and carpentry tools:

Two hammers: one medium, weighing 200-300 grams, and one heavy, weighing 800-1200 grams;
Longitudinal and transverse hacksaw for wood. Instead of a cross saw, it is more convenient to use an electric cutting machine;
A carpenter's plane, a large wooden mallet and a set of chisels;
As for electric tools, you need to have an ordinary household drill, and it is advisable to have a cordless screwdriver with a set of replaceable attachments;

To fasten rolled materials (waterproofing, vapor barrier), I recommend using a construction or furniture stapler with a set of metal staples;
You will also need a straight metal ruler, a tape measure 3-5 meters long, building level and a simple rope plumb line;
To work near the ceiling, it is most convenient to use a folding stepladder. If it is not there, you can adapt a high strong table or homemade goats from scraps of boards;
Lumber will be needed wooden blocks section 62x62 mm, and planed edged boards thickness 25-30 mm;

As a waterproofing layer, you can use a film of foamed polyethylene and a vapor-permeable waterproof membrane;
To seal the joints of the panels, you will need metallized aluminum tape, which is usually used in ventilation systems;
Materials for finishing ceiling, each homeowner chooses at his own discretion. This could be lining board, drywall, laminated OSB or plywood, or other finishing materials;

If you plan to use mineral or glass wool for insulation, then I recommend purchasing a special protective suit that is designed to work with these materials. Otherwise, severe irritation may occur on exposed areas of the skin from small glass fibers.

Stage 3: Filing the rough ceiling

When building an attic floor or erecting a sloping roof, you can do without expensive and heavy concrete floor slabs. Instead, the entire load from the roof is carried by wooden load-bearing beams made of logs or timber, with a cross-section of at least 120x120 mm. They are usually laid on top of two main exterior walls, perpendicular to the long side of the house.

Such beams serve load-bearing structure for the ceiling of the top floor, and for the floor of the attic. The same beams will be used for installing insulation between residential building and the attic. This type of ceiling is called hemmed, because both the rough and the finished ceiling are hemmed from below to the load-bearing beams.

Before insulating the attic floor, you need to mount the rough ceiling:

Illustration	Description of work
	Installation of a rough ceiling. To hem the rough ceiling, you should use dry edged boards 25 mm thick, or plywood sheets 10 mm thick or more.
	Hemming boards. They must be secured to the lower plane of the supporting beams and beams around the perimeter of the room. Hemming boards must be fastened without gaps or cracks, close to each other. For fastening, use galvanized self-tapping screws 5-6 mm.
	Waterproofing. When the entire rough ceiling is hemmed to the load-bearing beams, panels of foiled polyethylene foam need to be secured to it from below. This can be done using a stapler. "Penofol" will perform the functions of heat and waterproofing. It should always be placed with a foil layer towards the warm room.
	Sealing joints. To prevent moist air from the room from entering the insulation, the ends of the polyethylene film must be wrapped on the walls by 150-200 mm. The joints between the panels must be glued with metallized tape on an aluminum base.
	Fastening the sheathing. From below, across the entire area of the rough ceiling, nail a counter lathing made of wooden slats 15-22 mm thick. It is needed in order to provide a ventilation air gap between Penofol and the finished ceiling. The distance between the slats should be about 400-600 mm. In the future, a finishing ceiling covering will be attached to them from below.

Before starting work, everything wooden elements structures must be treated with antiseptic and fire-retardant impregnations. Antiseptics are needed to protect wood from rotting and mold development. Fire retardants give dry wood fire retardant properties.

Stage 4: Installation of thermal insulation

After filing the rough ceiling, the transverse load-bearing beams will be on the side of the attic. Insulation will be laid in between them.

Depending on the thermal insulation materials used, further installation technology may have some differences. Therefore, below I will briefly discuss the use of the most common types of insulation.

Laying mineral wool. Mineral insulation materials, when wet, partially lose their properties. To prevent condensation from forming in the mineral wool, the entire thermal insulation layer of the cold attic floor must be permeable to air and water vapor:

Illustration

Description of work

Vapor barrier. First, you need to lay a vapor-permeable waterproofing membrane on top of the rough ceiling.

Its peculiarity is that it freely allows water vapor molecules to pass through, but does not allow bound liquid water molecules to pass through.

The membrane panels must overlap each other by at least 150 mm;

Installation of insulation. Place sheets or rolls of mineral wool in the spaces between the wooden beams. If it is very soft, then it does not need to be squeezed or squeezed much.

Lay another layer of vapor-permeable membrane on top of the mineral wool.

To prevent it from moving over time, it must be stapled to the beams and walls, throughout the entire area and along the perimeter of the attic.

Installation of foam plastic. Polymer-based insulation does not have breathable properties, so it does not allow air and moisture to pass through. Use a waterproof membrane in in this case, it makes no sense:

Illustration

Description of work

Laying foam. Foam or extruded polystyrene panels can be laid between the cross beams, directly on top of the sub-ceiling boards.

I advise laying them in two layers, so that the joints of the sheets are located in different places, and did not intersect with each other.

Polyurethane foam. To prevent the insulation sheets from moving to the sides, they can be glued to the sub-ceiling using a special glue for polystyrene foam or polyurethane foam.

Thus, it is necessary to fill the entire area of the attic floor with insulation.

If there are gaps and cracks between the foam sheets, then they must also be blown out from a balloon polyurethane foam.

Clay with wood shavings. Insulating the attic floor with a sawdust-clay mixture does not require any additional materials, and is also quite simple:

Illustration

Description of work

Preparation of the solution. To make the sawdust-clay solution plastic, the clay must be soaked in water 2-3 days before starting work.

To prepare the solution, you need to take 3-4 volume parts of sawdust, and 1-2 parts of dry red clay without large solid particles and foreign impurities.

Mix the soaked clay with water until a liquid, flowing solution is obtained;

Add sawdust to the resulting mixture and mix thoroughly until smooth.

To protect against mold formation, you can add no a large number of copper sulfate.

Laying sawdust-clay mixture. Lightly moisten the supporting beams and boards of the rough ceiling with liquid clay milk.

After this, fill all the gaps between the beams with sawdust-clay mortar and leave for several days until completely dry.

Expanded clay backfill. I want to say right away that expanded clay does not have very good heat-insulating properties, therefore, in individual construction, such insulation of floors is rarely used. At the same time, it is considered inexpensive, unpretentious and the easiest to install:

Illustration	Description of work
	Preparatory work. Expanded clay pellets do not absorb moisture, and therefore are not afraid of water ingress or condensation. Therefore, they can be used both with and without a waterproof membrane. To prevent condensation from seeping through the ceiling into the house, I still recommend laying a waterproofing membrane under the pellets;
	Filling of pellets. Expanded clay pellets should be poured on top of the rough ceiling boards and evenly distributed in a thick layer over the entire area of the attic. No covering material is required on top of expanded clay.

To prevent expanded clay pellets from bunching up and spreading throughout the attic, a retaining plastic geogrid is used. It needs to be stretched in the spaces between the load-bearing beams, and then expanded clay should be poured into its cells.

Stage 5: Arrangement of the floor in the attic

Many residents use cold attic in your private home, as a storage room for storing long items, seasonal items and all unnecessary rubbish. In order for a person to safely walk on the insulated floor, a durable subfloor must be installed in the attic.

The choice of material for installing the floor in the attic will depend on the type of insulation used:

Illustration	Features of application
	Mineral wool and polystyrene foam. These materials themselves are very soft. To prevent them from being destroyed or wrinkled while walking, the top floor covering must be sufficiently rigid. In such cases, OSB or plywood sheets with a thickness of at least 18 mm should be laid on the load-bearing beams. You can also use unplaned edged boards with a thickness of 25 or 30 mm.
	Extruded polystyrene. It has higher rigidity, so it can withstand significant loads. To prevent it from being pressed when walking, it is enough to put a light flooring of thin boards or plywood 5-9 mm thick on top of it.
	Under the weight of a person, they will crawl in different directions. To prevent this from happening, you need to lay 10 mm thick plywood sheets or light wooden ladders made of boards on top of the beam floor.
	Sawdust-clay insulation. After the solution hardens, it becomes hard like cement. A person can move freely on its surface, even without installing additional flooring.

When installing rough flooring in the attic, you should always leave gaps 15-20 mm wide between boards or sheets of plywood. This is done so that moisture and condensation can freely evaporate from the insulation.

Conclusion

Using this operating algorithm, you can easily insulate the attic floor in your own home. More visual information on each method of insulation can be viewed in the attached video in this article, and I suggest leaving all your comments and questions in the comment form.

A room in the attic of a private household is used for various purposes: storing temporarily unnecessary things, installing equipment or arranging living rooms. Depending on what the free space under the roof is used for, the method of constructing the attic floor is chosen.

What is an attic

The attic space is limited by the roof slopes and the ceiling of the residential floor. This place is often used to create additional living space.

There are two types of attics in private households:

Residential. It is called an attic. It can be equipped with a living room, study, bedroom, library, etc. The height of the room in this case should be at least 220 centimeters. In addition, it is necessary to provide ventilation, natural lighting, and insulate the slopes.
Non-residential. This attic space is usually used to accommodate technical equipment, storing old or unnecessary things. In this case, a 2-meter height will be sufficient, and there is no need to provide natural lighting. Instead of insulating the slopes, they insulate the attic floor.

When making a decision to repair or rebuild a house, you need to decide in advance for what purpose the attic will be used in order to make calculations and a design for the floor. The list depends on this necessary materials and the gap between the beams. They must provide the required strength and load-bearing capacity.

Functional purpose of floors

The design of the attic floor depends on the parameters of the structure and the purposes for which it is planned to use the under-roof space. The attic functions as a kind of air gap that separates cold roof from heated floors.

The floor in the attic performs a number of tasks:

carrier. The floor, located between the upper residential floor and the attic space, is assigned a load-bearing function, so it is made reliable and durable, since people will move on it, they plan to place equipment on it and arrange storage areas;
insulating. In a cold attic, the temperature differs little from that outside the house. In this case, the floors in the attic have a thermal insulating function, thereby preventing the air from cooling on the residential floors. To retain heat, the attic floor needs to be insulated. It is advisable to entrust such work to professionals.

Features of the device and design of floors

Since the ceiling of attics performs two functions - load-bearing and insulating, they have a multi-layer structure. Each of the elements of the “pie” complements each other, which ensures the created structure has a long service life, strength and the ability to withstand heavy loads.

The construction of the floor in the attic requires the presence of the following layers:

Finish floor. This name is given to the floor covering, which is laid on a rough base. If it is an attic, then when installing the finished floor, linoleum, laminate, parquet, etc. are laid. In non-residential premises there may be no finishing floor covering.
Rough base. It is a boardwalk that is mounted on logs. The subfloor is lined with edged boards 4–5 centimeters thick or, to save money, with unedged boards.
Lags. These are strong, level pieces of wood that are laid perpendicular to the floor joists to create a floor covering. When installing an attic floor on wooden beams, insulation is placed between the joists, which is protected from below with a layer of vapor barrier, and covered on top waterproofing material. If you do not use insulating layers, then repairs will be required in a few years.
Beams. The frame of the floors is built from thick and strong beams, which are either mounted on the projections of the walls or built into them. They must support the entire weight of the structure. A flat roof can also be made using wooden beams, which is quite practical.
Headlining. From the side of the rooms, the ceilings are decorated finishing material, for example, natural wood or plasterboard.

Types of attic floors

To construct the ceiling of a cold attic, materials differing in weight, durability, cost and load-bearing capacity are used.

There are several types of floors depending on what they are made of:

Wooden elements. For their manufacture, you can use beams with a cross-section of 150x150 or 200x200 millimeters. The advantage of this option is that wood is quite durable and at the same time relatively light material, so wooden elements do not put additional load on the foundation of the house. In addition, their big advantage is their low price and availability. But such an attic floor is used when the size of the building does not exceed 6-10 meters, since this is the maximum length of lumber.
Metal products. Metal I-beams are distinguished by their strength and ability to withstand heavy weight without deformation. But they weigh a fair amount, so they are rarely used in wooden houses, but for brick and aerated concrete buildings they are the best option.
Reinforced concrete products. Molded floor beams, made from reinforced heavy-duty concrete, are used for multi-story buildings, since they are heavier and the same length.

Of all the above types of floors, in private low-rise housing construction, in most cases, preference is given to wooden beams. They have the optimal balance between price and quality. If the calculations are carried out correctly and the technology is followed, repairs to the ceiling will not be required in the coming years. Ventilation is also necessary in the attic of a private house, the arrangement of which will require additional knowledge.

Requirements for the device of the pie

Since the safety of staying in the house depends on the quality of installation and repair of attic floors, a number of requirements are imposed on their arrangement.

In order to know the maximum permissible load that the structure can withstand, it is necessary to perform the appropriate calculations, and then, based on their results, they begin to develop a project from which it will be clear how to properly insulate the attic floor in the house.

The requirements relate to:

Load capacity. It directly depends on the material used to make the beams and the gap between them.
Distances between load-bearing elements. Maximum allowed value for this parameter in accordance with building codes it is 4 meters.
Resistance to temperature changes. It is necessary that the beams can withstand such changes without problems. The fact is that the difference between the air temperature in the residential floors and in the attic always exceeds 4 degrees.
Isolation. The attic floor covering of a cold attic should protect the premises of the household from the penetration of cold and moisture from the under-roof space.

During the design process, you should take into account the requirements for the beams used to arrange the floor in the attic so that the result is reliable and durable. The distance between them must be calculated based on the loads exerted on them.

Technology for creating an attic floor using wooden beams

If you have experience construction work You can mount the ceiling of a cold attic using wooden beams yourself. This process is performed at the final stage of roofing work.

The sequence of actions will be as follows:

Installation of load-bearing beams. Suitable for a small private house wooden floors, made from timber with a cross-section of 150x150 or 200x200 millimeters. They are laid on concrete or brickwork walls
Installation of lag. They are placed on the edge perpendicular to the beams in increments of 60 centimeters. The logs are made from boards with a cross section of 150x50 millimeters.
Laying thermal insulation. The insulation is placed between the joists - it will protect against the penetration of cold from the attic.
Installation of rough and finished floors.
Covering load-bearing beams on the side of the room to decorate the ceiling surface.

When insulating the attic floor, you should not forget about installing hydro- and vapor barriers.

Insulating a house does not end with covering the walls, ceiling and floor with insulating material. As a rule, most private buildings have an attic. It should also be insulated depending on the desired temperature inside of this premises. There are two methods of cladding the attic floor - warm and cold. In the first case, the entire circuit is insulated so that the air under the roof warms up from exhaust ventilation. The second method involves only covering the floor. It is the insulation of a cold attic that will be discussed further.

Most often, a cold attic is found in multi-story buildings. The quality of its insulation affects the overall heat loss of the room, as well as the durability of the roofing and rafter systems. To improve heat conservation, you will need to place insulation between vapor and waterproofing materials. The first prevents the mineral wool from getting wet, which occurs due to the rise of wet masses to the top of the room. The second prevents moisture from entering from the roof of the house through cracks, holes, and gaps in the roofing material.

Work on insulating the attic is carried out more often from the floor than from the ceiling of the lower floor. The sequence of actions varies and depends on the selected insulation.

Many consumers choose mineral wool - a soft, reliable, inexpensive heat insulator with high compressibility, which allows you to cover even an uneven surface.

It is sold in rolls or soft slabs, and is cut with a stationery or with a simple knife of sufficient size.

The positive properties of mineral wool are:

high fire resistance;
resistance to moisture;
the material is not afraid of rodents;
Ease of use;
affordability.

Despite the relative simplicity of the material, when working with mineral wool you need to use protective gloves, glasses, thick clothing with long sleeves (covering your hands completely), and for those prone to allergic diseases, a respirator.

Required tools and equipment

To fully insulate the ceiling of a cold attic with mineral wool you will need:

vapor barrier (special membrane or polyethylene film);
waterproofing (a classic example is roofing felt);
several rolls/slabs of mineral wool (the quantity is determined by the area to be insulated, the climatic conditions of the region, as well as the desired number of layers of insulation);
scotch;
tape measure, preferably from 5 m;
stationery knife;
construction stapler;
boards and sheets of plywood (to form areas within which the material will be placed);
spatula (for leveling/compacting the insulation).

If everything you need is ready, it’s time to get to work.

Instructions for covering the attic floor

Proper insulation of a cold room involves the sequential implementation of the following steps:

Laying vapor barrier material on the floor. They can be a vapor-proof membrane, polyethylene film or glassine. The first example is the most expensive, the last is the most affordable. The material is laid with an overlap, the joints are glued with tape or fixed with thin wooden slats using a stapler.
Logs (horizontal sections) are formed from plywood or small blocks. The distance between parallel boards should be a couple of centimeters less than the expected width of the insulation.
The mineral wool is placed tightly into the logs and compacted with a spatula so that there are no gaps. If it is necessary to lay two pieces of insulation, their joint is taped.
It is advisable to lay a waterproofing material on top of the wool layer to prevent the floor from getting wet. Most likely, there is already a layer of roofing felt under the roof, but for greater peace of mind it is recommended to perform this step when insulating a cold attic floor.
After laying three layers of attic protection from freezing and moisture, smooth boards are laid on top of the joists to form the floor.

Fulfillment of the above plan is the key to quality work done. A flat floor laid on top of the insulation is the base surface for final finishing.

Features of working with the material

Compared to polystyrene foam, expanded polystyrene or similar insulation, mineral wool is an order of magnitude superior to them in terms of safety precautions. In addition to the previously mentioned rules regarding clothing, the following regulations must be observed:

cut pieces of mineral wool only on a horizontal, flat surface;
lay it in a layer the width of which is at least 25 cm;
insulate pipes, ventilation shafts, beams and other areas protruding in the attic near the floor with mineral wool.

Obviously, insulating a cold attic with the material considered is an elementary process, which is complicated only by the properties of wool. Compliance with the installation technology will give warmth to your home for many decades, and the insulation used will perform its functions efficiently.

The presence of an attic in the house opens up new opportunities for the owners. Firstly, it helps to give a stylish appearance the structure as a whole, and secondly, it rationalizes and increases living space. Provided all rules are followed, the attic can be used as a full-fledged residential floor. When constructing an attic, special attention should be paid to the arrangement of the floor. In order for the floor of the second floor to meet state standards, to be durable and reliable, it is necessary to follow the established rules during construction activities.

Features of the attic

Before you begin work on creating a high-quality and warm floor in the superstructure, you should know about the main features of such a room:

The attic floor can have any geometry, it all depends on the choice of roof type. These can be broken, symmetrical or asymmetrical designs. The location of the under-roof space can be along the entire length, or also located on one side of the longitudinal axis.
The location of the attic floor can extend over the entire quadrature of the building or over any part of it. If the projection is limited, then such a room falls on the removal of the console.
The planned project depends on several factors. The main parameter is the architecture of the entire structure and load bearing capacity walls of the house.

Advice! To install the floor, ceiling and walls on the attic floor, experts recommend choosing relatively light building materials so as not to burden the structure of the entire house.

As a rule, the attic area is large, so it is important to avoid heat loss during the arrangement. Despite the fact that the bottom plane is not in contact with external environment, the area needs high-quality thermal insulation.

The attic can have any configuration, which opens up new opportunities for interesting design projects. In addition to the aspect of rationalization and increasing full-fledged living space, the attic floor is economical. Practice shows that the construction of an attic is cheaper than the construction of a full floor of the same area. Except functional benefits, one cannot help but say about aesthetics. Attics give the entire building a more expressive and unusual look. Understanding the features of constructing an attic floor in a private house, you can take into account everything during planning important points when arranging the floor in order to avoid mistakes and discomfort in the future. Particular attention should be paid to floor insulation.

Arrangement of the lower plane

By virtue of design features attic, when arranging the floor, you need to remember that to climb to the second floor you will need to equip a hatch, which will subsequently connect to the stairs. To do this, you need to choose its location and leave enough space for its device. The algorithm for arranging the lower plane of the attic floor is as follows:

We carry out cleaning to prepare the base. To do this, we remove debris, tools and foreign objects from the surface.
The next step is to check the strength of the floors. What is it for? It is the floors that bear the main operational load, so making sure of their strength and reliability is extremely important. We carefully examine the beams for integrity and absence of rotting.
We prepare wooden logs. Their installation is a fundamental stage; the work depends on several factors. The choice of lag section and the distance between them during installation depends on the pitch of the floors, as well as the thickness of the board. The length of the logs must correspond to the dimensions of the roof space.
Installation of the outer support strips. Installation and fastening is carried out using self-tapping screws or nails. The planks are fixed directly to the pediment or side partitions. The installation principle is determined by the location of the roof structure.
It is necessary to place a strong crossbar along the edge of the proposed hatch. To ensure reliable fastening, you can use steel corners.
After the final determination of the location of the hatch for the entrance to the attic floor, the remaining logs are installed, taking into account the design features. In this case, the wooden crossbars should be located in the same plane.

It must be remembered that the floor in the attic is the ceiling for the lower floor in the house. Therefore, the reliability of the floors and high-quality arrangement will be the key to comfort and safety for all household members. At this stage, the preparatory work for arranging the floor has been completed. You can move on to an equally important part of the work - insulation.

Choice of insulation

When choosing a gasket for the floor on the attic floor, you need to avoid making the structure heavier. There are many materials for insulating buildings on the market. Which one is optimal for insulating the attic floor should be examined in detail. We remember that the ceiling of the lower floor is also the basis for the attic. Therefore, heavy insulation materials should be avoided, as they place excessive stress on ceiling beams and floors. Experts recommend the following insulation materials:

Polystyrene foam is the simplest way to insulate a floor. Advantages:

affordability;
excellent thermal conductivity;
moisture resistance and biological stability;
ease of installation.

In addition to the advantages of using polystyrene foam as insulation for floors in attics, there are also disadvantages. The material has low vapor permeability, little strength, and is also a fertile environment for rodents.

Extruded polystyrene. A representative of the modern generation of floor insulation, which has the following advantages:

high levels of moisture resistance;
low thermal conductivity threshold;
groove fastening system.

The disadvantages include the high cost of the material and low vapor permeability.

Mineral wool - optimal choice for insulating the floor in the attic. Pros of use:

the material is fireproof;
has low thermal conductivity;
moisture resistant;
environmentally friendly for households.

The disadvantages include the high cost and the presence of joints during installation. The cracks and joints that may result from installation must be sealed with special mastics.

Expanded clay is one of the most effective materials for floor insulation. This insulation is a budget option with good characteristics. Pros:

lightness;
maximum filling of voids;
environmental Safety.

Important! When choosing expanded clay for floor insulation in an apartment or semi-attic, you need to take into account its shrinkage, the coefficient is 1.15.

Glass wool is considered a classic insulation material. But, along with safer and more modern thermal insulation materials its characteristics are not ideal. When choosing floor insulation, you need to proceed not only from financial capabilities, but also from the aspect of durability. As they say, the miser pays twice! Therefore, savings in measures to insulate the attic floor are not appropriate.

Insulating the floor in the attic

Arrangement of the floor in the superstructure is an important step. During the process, it is necessary to eliminate any errors that could lead to negative consequences. As a result of improper installation, the ceiling of the lower floor of the house may be damaged. The algorithm for floor insulation includes several stages:

Creation of a high-quality vapor barrier layer. To do this, the entire prepared surface is covered with a special film. This is necessary in order to avoid the accumulation of condensation from the lower floor. When laying the covering, you need to make an overlap of 15-20 centimeters.
Installation of insulation. Insulation is placed in the gaps between the joists. It is important to monitor the formation of gaps between the plates, so it is recommended to make an overlap of 2 centimeters.
The next layer of vapor barrier film is placed on top of the insulation. In this case, installation is carried out on a flat surface, and the material is secured to the joists with staples or nails.
The sheathing is being prepared for laying the floor boards.
Laying is done on top of the crossbars wood flooring. You can use veneer or edged boards. The joints between the planks are fastened with staples, screws or nails. This type of flooring is called a subfloor.
Produced finishing floor.

When using wood in work, attention should be paid to antiseptic and fire protection treatment. This will help prevent rotting as a result of moisture and will increase the level of fire safety in the room.

Important! Between the layers of hydro- and vapor barrier it is necessary to create an air gap of 50 millimeters. This will help increase the service life of the attic floor!

When choosing materials for flooring, preference should be given to lightweight, energy-saving, vapor-proof and sound-proofing materials.

Installation of floors on the second floor.

There are several basic rules for creating a high-quality, durable and reliable floor on the attic floor:

The main focus is on sealing the entire structure. To do this, all joints, corners or crevices are treated with sealant lubricants or insulating tape.
When installing a self-leveling floor, the surface is pre-primed. For a perfectly flat floor, a self-leveling mixture is used, diluted with water in the correct proportion. You can lay tiles, carpet, laminate or any other decorative covering on such a floor.
Do not leave the space between the joists empty. If voids are not filled, the floor can resonate with a loud, booming sound. To fill the space, you can use loose insulation, expanded polystyrene granules or expanded clay chips. This technique helps to perform sound insulation and insulation at the same time.
It is better to do floor insulation using a two-layer method. In this case, ligation of seams and beams with a thickness of at least 150 millimeters is performed.

The arrangement of the floor depends on what material the floors in the house are made of. These can be wooden beams or reinforced concrete floors. When installing a floor, you should pay attention not only to the choice of quality materials, but also to safety precautions. Having learned all the details and the step-by-step algorithm of actions, you can do all the work with your own hands no less efficiently than experienced professionals will do.

Proper insulation of the attic and attic ceiling.

To understand why it is necessary to insulate the ceiling of a cold attic, let’s clarify a little why an attic is needed in a private house and what its purpose is. Our ancestors built houses that could last for more than 100 years, while it was warm inside, and wooden structure the roof always remained dry.

Previously, they mainly built gable roofs with a slight slope of the slopes. This was done so that snow could remain on the roof in winter. Thus, snow was used as a natural insulation. One or two windows were made in the attic and kept closed in winter so that the trapped air acted as a heat insulator. In the summer, a slightly different situation occurred. Attic windows were opened at night so that the air cooled, and during the day, in hot weather, they were closed so that the air did not heat up too much, thus regulating its temperature.

When snow fell in winter, it fell as a continuous cover on the roof, simultaneously becoming a natural insulation. Even in severe frosts, the temperature in the attic did not drop below zero. Thus, the air in the attic and the insulation of the ceiling made it possible to maintain the temperature in the house at +20-25 °C. The roof slopes were not insulated to prevent the snow lying on the roof from melting. Rafter system remained open, allowing it to be inspected and repaired if necessary. Therefore, in a cold attic, only the ceiling is insulated.

If the roof slopes are insulated, then the attic becomes a heated room, i.e. an attic, which has a completely different functional purpose.

Now it remains to find out how to insulate the attic floor in a private house, and what materials are used for thermal insulation.

Materials for insulating attic floors

Present on the market a wide range of materials for insulation. To make a choice, it is necessary to take into account the conditions in which the thermal insulation material will be used:

The material must retain its properties when temperature conditions from -30 to +30 °C. It should not freeze in severe frosts and should not emit harmful substances in hot weather.
It is necessary to choose fire-resistant insulation if there is electrical wiring in the attic.
It is better to choose a moisture-resistant material so that when wet it does not lose its thermal insulation properties.
The insulation should not quickly cake in order to fulfill its purpose for as long as possible.

Before deciding on the type of material for insulating the floor of a cold attic in a private house, you need to consider what material the ceiling is made of. If the attic floor is made of wooden beams, then you can use slab, roll and bulk insulation. In the case where the attic floor is made of concrete slabs, they resort to the use of heavy bulk or dense slab heat insulators. Their use makes it possible to make a cement screed on the floor.

Materials produced in slab and mat formats:

mineral wool (mineral wool) in mats;
Styrofoam;
extruded polystyrene foam;
seaweed;
straw.

Roll insulation:

mineral wool;
glass wool;
stone wool;
seaweed ladders;

Bulk materials for attic floor insulation:

expanded clay;
ecowool;
reed;
sawdust;
straw;
slag;
buckwheat tyrsa;
foam granules.

Insulation of attic floors wooden house must be made with environmentally friendly, natural and breathable material.

How to properly insulate an attic floor with mineral wool

Mineral wool is a common and modern heat insulator. Available in rolls or slabs (mats). It does not rot or burn, rodents and various kinds of microorganisms are also not afraid of it.

Insulating the ceiling of a cold attic with mineral wool begins with laying lining material on the floor. For a budget option, glassine is laid on the floor, but a more expensive and high-quality option is flooring made from vapor barrier film. The film is laid with an overlap, and the joints are taped or secured with wooden slats, which are fixed with a construction stapler.

The width of the insulation is selected based on the requirements of thermal engineering standards for each region. Mineral wool is placed between the joists tightly and without gaps. The joints are taped with tape. After the insulation is laid, level boards are simply laid on the joists, thus forming the floor in the attic. This simple solution for creating a floor allows the mineral wool to “breathe” and ventilate normally if it gets wet. To prevent moisture from entering the mineral wool, waterproofing material is laid under the roof.

Mineral wool is laid in means personal protection: thick clothing, glasses, gloves, respirator.

Insulation of attic floor slabs with extruded polystyrene foam

Expanded polystyrene or polystyrene foam are not very dense materials, so they are used when the attic floor is a structure made of joists and beams. If thermal insulation of the slabs is necessary, insulation of the cold attic floor with extruded polystyrene foam is used. This material is stronger and therefore denser than regular foam. Before laying it, the surface of the slabs should be leveled. There is no need for vapor barrier on the warm side of the floor, since concrete slabs have almost no vapor permeability.

A vapor barrier film is laid on the leveled concrete slabs. Next, slabs of extruded polystyrene foam are laid in a checkerboard pattern. The joints are blown with polyurethane foam. After the foam has dried and hardened, the insulating slabs are poured with concrete mortar 4-6 cm thick. When the screed is dry, it is already suitable for use as a floor. Although you can go further and put any floor covering on the screed.

Thermal insulation of a cold attic with ecowool

Ecowool is a cellulose, lightweight and loose insulation material, consisting mainly of waste paper and newspapers. Other components - borax and boric acid - are used as flame retardants.

Before insulation, it is necessary to place a film on the floor. The procedure for laying ecowool occurs using a special blowing installation. The insulation layer is applied as a continuous cover, without creating cracks. Since ecowool contains a large amount of air, a layer of 250-300 mm is usually enough.

Do not forget that over time, the material will shrink. Therefore, apply a layer of ecowool 40-50 mm more.

After the insulation of the cold attic floor with ecowool is completed, it must be moistened. You can do this with plain water or prepare a solution of 200 grams. PVA glue on a bucket of water. Moisten ordinary broom in this solution and moisten the cotton well. After drying, a crust forms on the surface of the cotton wool - lingin, which will not allow the cotton wool to move.

As you can see, there are plenty of ways to insulate the floor in the attic. Which one to use depends on each specific situation. The main thing is to comply the right technology laying thermal insulation! Then your home will always be warm, and the materials used will last for many years.