Roof insulation with expanded clay: environmentally, reliable, safe

Are you trying to find a good and sustainable way to insulate your roof? Expanded clay is a material that can be used for many purposes and is dependable and sustainable. Expanded clay is produced by firing natural clay in a rotary kiln, which releases trapped air and causes the clay to expand into lightweight pellets. A porous structure with superior thermal insulation qualities is produced by this process.

The environmental credentials of expanded clay are among its most notable qualities. It’s a renewable resource because it comes from natural clay deposits that are plentiful. Compared to many other insulation materials, the manufacturing process uses less energy, which lessens the material’s environmental impact. Furthermore, expanded clay is chemically inert and non-toxic, meaning that neither the environment nor human health are at risk from it.

Expansioned clay insulation is highly reliable in a number of areas. Because of its lightweight design, it is simple to handle and install, which lowers labor costs and logistical difficulties during construction. Expanded clay, although lightweight, provides good thermal insulation, lowering energy requirements for heating and cooling while assisting in the maintenance of comfortable interior temperatures.

Expanded clay insulation is renowned for its longevity and durability as well. It doesn’t deteriorate over time and keeps its insulating qualities for many years. Because of its long lifespan, it requires less upkeep and replacement, which lowers the overall cost. Its appeal as a trustworthy and safe insulation material is increased by its resistance to fire, mold, and pests.

In summary, using expanded clay as roof insulation improves comfort and energy efficiency while also being consistent with sustainable building methods. Because of its natural origins, longevity, and safety, it’s a material of choice for both environmentally conscious builders and homeowners.

Ceramzite insulation: Pros and cons of solutions

Contemporary heat-insulating materials work incredibly well. However, these benefits are frequently offset by significant drawbacks: certain heaters are extremely flammable and ignite easily; Others just smolder, but they can be distinguished from poisonous substances that harm humans gravely even in the absence of fire; The third loses its ability to insulate heat when it gets wet and is incredibly hygroscopic. In contrast to artificial heating, expanded clay

  1. Does not burn or smolder. Expanded clay is porous granules of burned clay, so it is absolutely fireproof.
  2. Environmentally friendly material. For the production of expanded clay, only clay, high temperature and rotating capacities-drums are needed. No dangerous by the ecology of by -products of production and additives.
  3. It is inexpensive. You can buy expanded clay at a price of 3000-3500 rubles per m3. From insulation is cheaper in terms of the thickness of the required layer of insulation will cost only foam and glass wool. But take into account that such a price of expanded clay is valid only when it is purchased in bulk or in large packages like Big-begs.
  4. Durable. The service life of products made of burned clay is calculated not by dozens or hundreds, but thousands of years. Clay dishes of the times of ancient Greece, which are filled with museums, the best confirmation.
  5. Resistant to fungus and mold, rodents. There are no mold or fungus on dry expanded clay.
  6. Resistant to freezing and temperature extremes. Keramzit can withstand 150-300 freezing/defrosting cycles and a significant increase in temperature up to 700-800 ° C.
  7. Lasting. Keramizite poured onto the roof or overlap easily withstands a person’s weight even without boards laid on top.
  8. Fills the cavities. The main clay fraction for insulation is 10-20 mm, but usually it is mixed with smaller material. The resulting bulk mixture perfectly fills any cavities and cracks, preventing the formation of cold bridges near the boards and walls.

Furthermore, using expanded clay for ceiling insulation has two beneficial side effects. The first one is a thick layer of excellent sound insulation. This is particularly true for homes with corrugated metal roofing, metal tiles, or folding roofs that obstruct the sun. The expansion of the expanse equally presses on all the building’s structures, causing a uniform shrinkage of buildings made of wood and logs as the second side effect.

To provide a comprehensive overview, the following are the drawbacks of using expanded clay as insulation:

  1. The thickness of the layer. An effective layer of expedents for insulation is at least 200 mm with open backfill, otherwise the material simply does not work – warm air goes through the cavities between the granules.
  2. Light weight. Although expanded clay density is small-for insulation of roofs, the material is used with a density of 250-350 kg/m3-it still strongly loads the structures of the house due to the thick layer.
  3. A lot of dust. It is necessary to fall asleep expanded clay in the respirator and glasses due to the large amount of fine dust, which is formed when laying it.
  4. Hygroscopicity. Keramzit absorbs moisture very well – the water absorption of whole granules reaches 25%. This increases the weight of the material and worsens its heat -insulating properties.
  5. Fragility. Fighted clay granules – durable, but fragile material. Explorer is easy to break, and damaged granules fulfill their function worse.
  6. It is difficult to use for pitched roofs. Like any loose material, expanded clay is difficult to pour on any inclined planes.

Expanded clay does not need to be compared to the hygroscopicity of stone cotton wool, even though it is extremely large and can cause issues if there is a leak in the roof. Yes, porous clay will give it reluctantly and for a long time if moisture penetrates the thick layer of expanded clay used to warm the ceiling. It will still dry out eventually, though. However, it is nearly impossible to dry the wet mineral wool.

Expanded clay is generally almost perfect for use as a heater for ceilings and flat roofs, provided that the thermal insulation layer’s thickness is unrestricted and the foundation and supporting structures are strong enough to support the added weight.

What expanded clay is needed to warm the roof

Expanded clay is made of clay granules, which are loaded into a rotating stove-drum mounted with a small slope. Gradually rolling down the walls of the drum, the granules become oval and warm up to 1300 degrees. When firing, they swell, becoming porous inside, and on the outside they acquire a smooth, rounded surface. Damage to this surface leads to an increase in the hygroscopicity of expanded clay and the deterioration of its heat -insulating properties. Therefore, when choosing expanded clay for insulation of the roof, first of all, make sure that its granules are whole. Of course, with large volumes, damaged granules will inevitably be, but there should be some.

Which expanded clay now occurs:

  1. Expanded clay sand. In fact, production waste – small particles of an arbitrary shape of not more than 5 mm in diameter, which are abandoned from granules when they are running out in the drum. Thermal conductivity of expanded clay in the form of sand is about 0.16-0.17 W/(m · K), rarely lower.
  2. Expanded clay gravel. Oval pellets with a diameter of 5 to 40 mm, which are used as a heater. Thermal conductivity is from 0.1 to 0.16 W/(m · K), on average 0.7-0.12 W/(m · K).
  3. Expanded crushed stone. The material that is crushed by large sprinkled pieces of clay, so the crushed stone has the wrong shape and sharp edges. It is not used for insulation – sharp edges can break a steam -barrier or waterproofing, and the damaged shell greatly reduces the thermal insulation properties of the material.

Generally, the plant divides expanded clay into three fractions: 5–10 mm, 10–20 mm, and 20–40 mm, in the form of pellets. Occasionally, they separate the largest granules into two groups (20–30 mm and 30–40 mm) and create four fractions. Generally speaking, a material with more granules has a lower thermal conductivity and can therefore retain heat better. Thus, the type of clay fraction used directly affects the required thickness of the thermal insulation layer. However, the ceilings and roofs are typically not insulated. The roof has very large 30–40 mm granules, and because of the large spaces between the pellets, heat escapes through a lot of cavities.

Expanded clay sand, which serves as an underlying and leveling layer, makes up 10% of the volume of expanded clay roof insulation in private homes. The remaining three materials are typically 50% expanded clay gravel (10–20 mm) and 40% expanded clay gravel (5–10 mm). With these measurements, you can create a thick layer of insulation with full cavities that will consistently hold heat.

Expanded clay is a reliable and sustainable option for homeowners who care about the environment when it comes to roof insulation. Expanded clay, well-known for its organic makeup and energy-saving qualities, works well as insulation, preventing heat loss in the winter and keeping houses cool in the summer. It is perfect for family homes because it is risk-free and safe, unlike synthetic alternatives. Because of its long lifespan, low maintenance needs, and gradual energy savings, it is reliable for a long time. By reducing environmental effect, using expanded clay as roof insulation not only improves comfort but also contributes to a more environmentally friendly future."

How to insulate the roof with expanded clay

Since expanded clay is a bulk material, there are differences in the insulation technologies used for pitched and flat roofs and ceilings. except for the preparatory, at every stage.

Tools and materials

Expanded clay insulation for roofs requires common household tools that are owned by every home master:

  • screwdriver;
  • construction knife;
  • hammer;
  • roulette, pencil and construction level;
  • a scoop that will be conveniently gaining expanded clay;
  • rule (can be replaced with a flat board);
  • bucket.
  • Expanded clay sand, expanded clay gravel of fractions 5-10 mm and 10-20 mm in proportions 1: 4: 5;
  • A torn board with a thickness of 20-25 mm (for insulation of the ceiling with expanded clay is replaced by a beam of 20 × 20 mm or 25 × 25 mm);
  • vapor barrier;
  • waterproofing membrane;
  • Self -tapping screws, dowels, if the boards need to be attached to the concrete overlap;
  • reinforced adhesive tape;
  • Sensor thread.

It is necessary to apply an antiseptic and a fire-retardant mixture to boards and beams, then allow them to dry. When installing expanded clay insulation in an attic with previously installed roofing, overlap is the only method used. A crate for backfilling exponents from the inside cannot be fastened to the rafters because the weight of the fastening material will weaken it over time and cause the insulation between the cells to wake up. In the event that the roof structure is damaged, the crate may even take on an avalanche-like shape.

What layer of expanded clay is needed to warm the house

Similar to other thermal insulating materials, the joint venture 50.13330.2012 "Thermal protection of buildings" calculates the normative value of the structure’s resistance to heat transfer, or R, which determines the layer’s thickness. In summary, the interpretation of R is contingent upon the nature of the design and structure, as well as the local climate during the construction phase. The design documentation should include a calculation for this value. If this isn’t the case, or if you insulate your home without a project using expanded clay, you’ll need to figure out how much heat resistance you need.

Using the well-known R You can use the following straightforward formula to determine which layer of expanded clay insulation you need in your situation:

Where K is the expanded clay’s coefficient of thermal conductivity, which can be found on the package or by contacting the manufacturer, and P is the layer’s thickness in meters. In the event that this is not achievable, 0.16 W/(m · K) is assumed to be the thermal conductivity.

We provide the average values of the insulation thickness in various scenarios for those who prefer not to perform calculations. Thus, what is the necessary layer of expanded clay for insulation?

  • in the southern regions-20-25 mm;
  • in the middle lane for flat roofs – at least 40 mm;
  • for the pitched roof – no more than 30 mm, if a large thickness is needed, it is obtained by other types of insulation;
  • for overlap – at least 30 mm, better 40 mm.

Remember that the bearing capacity of the foundation, walls, and rafter system of the house affects the thickness of the expanded clay insulation in addition to the value of the required resistance to the heat transfer of the structure. Simultaneously, the snow load must be considered, as it can reach hundreds of kilograms per unit area even in the Russian Federation’s middle lane, let alone the northern regions. Consequently, expedents are typically not used for insulation in the northern regions.

How much expression is needed for insulation

Use the following formula to determine the amount of expanded clay required to insulate the roof or attic overlap:

Where h is the estimated thickness of the claymzite layer in meters, V is the volume of expanded clay in meters, and Insulation area in meters squared (S) and correction coefficient (n), which is assumed to be between 1.05 and 1.2. The shrinkage of expanded clay during compaction is taken into consideration by this coefficient.

  • For attic floors n = 1.05;
  • For pitched roofs n = 1.1;
  • For flat roofs n = 1.2.

If such an opportunity arises, it is preferable to purchase expanded clay with an extra 5–10% margin. The truth is that expanded clay is far less expensive in large bags and embankment form than in packages of several tens of liters that are sold in garden and construction supply stores. The difference is so great that purchasing additional hundreds of liters is frequently more cost-effective than purchasing the small amounts of expanded clay that are missing. Furthermore, expanded clay expeditions can be used in private homes for alpine slide devices or indoor plant drainage.

Ceramzite insulation of attic ceiling

The surface needs to be ready before any work is done. Trash and dust should be removed, and any cracks or irregularities should be sealed. No matter how much expanded clay you put on the floor, if the cracks are not sealed, a lot of fine dust will enter the living room and be challenging to remove.

The first step in overlapping cement masonry is to lay a vapor barrier that is equipped with overflows. Without a doubt, the film needs to extend 20–25 cm toward the walls and other buildings. A vapor barrier with enclosing structures has joints and seats that are carefully glued together using reinforced tape. If paper clips or nails are used to secure the film to the overlap, the fasteners need to be taped shut as well.

A vapor barrier layer is topped with an expanded clay backfill frame. It is constructed from a beam that is arranged in either one or two rows.

Beams are attached in rows in steps of one to one and a half meters. In this instance, the beam’s thickness is determined by the layer of expanded clay that is required for ceiling insulation. In the event that the insulation layer calculation is 40 mm, for instance, a 20 × 40 mm or 25 × 40 mm beam will be used to install the frame. Installing a single-row frame is simpler, but in this scenario, every beam acts as a bridge for cold, allowing heat to escape the room beneath it. The frame is made with two rows to prevent this.

A beam with a thickness equal to half the estimated thickness of the claymzite layer for insulation is used for a two-row frame. Every one to one and a half meters, the first row is also fastened. Expanded clay is then poured into the spaces between the strips. Next, a second row of beams is installed, with the same step and fixed perpendicular to the first row. This makes it possible to apply expanded clay to the first row’s bars and virtually eliminate the cold bridges, which will only remain where the cranker bars cross.

The leveling layer of expanded clay sand is always the first step in filling the insulation, regardless of the type of expanded clay you choose to warm the ceiling. Typically, it has a 5 mm thickness. The nylon thread is pulled in parallel to it at the appropriate height to create an even layer of sand in the middle of the space between the bars. The sand is then poured in between the bars, compressed, and the rule is defeated.

To make the insulation layer dense, the fractions of expanded clay gravel are mixed. This is done either in a bucket or other container before filling, or the finished mixture of expanded clay is ordered at the factory. Gravel is poured between the bars with a layer of 10-12 cm, compacted, then poured the same layer again and again trim until the desired thickness of the insulation is reached. The fully poured layer of expanded clay is aligned with the rule, using the upper edges of the frame as beacons. At this stage, insulation can be completed if the attic is not planned to be used to accommodate things and other tasks. If there are such plans, then on top of expanded clay you need to make a flooring.

Expanded clay is sealed with an additional layer of vapor barrier prior to flooring installation, following the same guidelines: overlap, joints sealed with reinforced tape. Over the vapor barrier, a plank floor is constructed, using the frame for support and fastening.

Warming of a flat roof

Vapor barrier film is typically not used on flat roofs because it can be accidentally damaged by filling expanded clay, which can cause the roof to leak. The roof’s surface is first coated in two layers of primer rather than a film. To improve bitumen materials’ adherence to the concrete base, it is necessary.

After that, bitumen mastic is put to the primer, and bitumen roll waterproofing is put on top of that. A bulk roof is an additional option for waterproofing. Since the coating is elastic, monolithic, and extremely durable, leaks are essentially eliminated. However, the bulk roof costs more than regular roller bitumen coatings.

Continue on to the expanded clay clayflow. Backfill follows the same general procedure as overlap: layers of 10–12 cm of mixed expanded clay gravel are placed first, followed by expanded clay sand, and then their seal is applied. The parts of the marking cord stretched at the desired height are used at the desired height; only on a flat roof do they not form the frame, but rather serve as the beacons that determine the alignment of the expanded clay layer. It must be pulled parallel to one of the walls, with no more than two meters separating the markings; otherwise, it will be challenging to pour the insulation evenly.

Additionally, expanded clay on an underutilized roof is simply covered with a film that acts as a vapor barrier, complete with overlaps and gluing joints, before a roofing material—which must be trained on the walls—is laid on top. It is preferable for roofing material to fully seal parapets, including those accessed from above, for increased dependability.

If creating a terrace on a flat roof is the plan, a damper tape is placed near the parapet even before the clayflow of expanded clay. It is necessary to prevent the screed from cracking when its size increases due to temperature changes. The thickness of the expanded clay layer and the upcoming screed should be entirely covered by the width of the tape. The roof is then completed in three steps:

  • A reinforcing mesh is laid over a layer of expanded clay;
  • Then pour a cement-sand screed with a layer of 40-50 mm;
  • The screed is aligned according to the beacons installed on expanded clay and leave to gain strength for about a month;
  • The resulting base is again primed by a primer in two layers;
  • Bitumen waterproofing is either laid on top of the screed, or a bulk roof is made.

Depending on your plans, you can immediately install paving slabs, a terrace board, or install drainage with the ground and plants on the waterproofing that has been completed. By the way, expanded clay is better than other forms of insulation because it allows you to create a slope on an even coating, based on the reviews of the green roof owners. This is required to prevent the green roof from becoming a swamp after an especially heavy downpour. Excess moisture must be drained into the drainage system, which is impossible without a slope.

Statement of the pitched roof with expanded clay

Many people are unsure if expanded clay can be used for thermal insulation of a pitched roof because fining heaters and pitched roofs are such an uncommon combination. Although it isn’t common, expanded clay gravel is occasionally utilized for this purpose. primarily in the southern states, and if the building is subject to stricter fire safety regulations.

Expanded clay is used to insulate pitched roofs over rafters. This allows the expanded clay to lightly touch the flooring and aid in the breakdown of fasteners when installing the frame from the inside. In order to accomplish this, the flooring is fastened to the 20–25 mm thick overlaid boards’ rafters. Should the need arise, they can be substituted with an OSB-plate of equivalent thickness or plywood that can withstand moisture. It is imperative that the flooring be installed without any cracks; therefore, either use calibrated boards or bring regular trimming boards to refer to the flight’s sizes.

The completed flooring is covered with an overlapped vapor barrier film, fastened with construction staplers. To stop water vapor from seeping through the holes where the fasteners are, the vapor barrier must be glued with reinforced tape.

The frame’s beam, whose thickness should match the estimated thickness of the claymzite layer, is fastened to the flooring by means of metal corners. A 0.5 m step is used to attach the beam parallel to the cornice. The vertical steps of 1.5 meters are spaced between horizontal bars on the same corners. They are required to secure the poured expanded clay beneath the second layer of plank flooring. The ends of the beam are covered with boards that match in width on the front-line overhang.

Boards are sewed into the resulting rectangular cells from below approximately in the middle. The space between two plank flooring pieces is filled with a mixture of expanded clay gravel made up of two fractions and tamped down. Pitch roof insulation does not use expanded clay sand. Until the cavity is filled, more granules are added to the compacted expanded clay. Vertical bars then fasten a second upper board, and so on, filling the cavity once more with compacted expanded clay and continuing until the second layer of flooring completely closes off the roof.

Unfortunately, it is impossible to lay loose insulation evenly on an inclined surface. Gravity gets in the way. Consequently, there will be more in the lower than in the upper portion of the expanded clay. It will be necessary to accept this. Cold typically opposes the installation of an insulation layer from the inside of the roof with the resulting bridges.

The completed flooring is covered with a waterproofing film that is fastened with a counterparty. You must install the crate or another continuous flooring above the counterparty, upon which the roofing will be installed.

Expanded clay provides a strong combination of dependability, safety, and environmental advantages when used as roof insulation. This lightweight aggregate material helps with sustainability initiatives in addition to improving buildings’ energy efficiency. Homeowners and builders can minimize their environmental impact and lower utility bills by choosing expanded clay instead of other building materials that require as much energy for heating and cooling.

Expanded clay’s natural composition, which is devoid of dangerous chemicals and volatile organic compounds (VOCs), is one of its unique qualities. Because of this, it’s a safe option for indoor air quality, guaranteeing that residents won’t be exposed to pollutants and will instead live in a healthy environment. Furthermore, because expanded clay is inert, it doesn’t deteriorate over time and provides long-lasting insulation performance without requiring frequent replacements.

Practically speaking, expanded clay offers superior thermal insulation qualities when used as roof insulation. By reducing heat gain in the summer and heat loss in the winter, it efficiently controls indoor temperatures, resulting in a more comfortable living or working environment all year long. In addition to improving comfort, this thermal stability lowers the carbon footprint involved in preserving ideal indoor temperatures.

Expanded clay has practical benefits, but it also supports green building techniques. It further lowers associated carbon emissions by eliminating the need for long-distance transportation because it is a naturally occurring material that can be sourced locally in many regions. Its low energy consumption during production makes it more environmentally friendly than synthetic alternatives.

Video on the topic

We warm the roof_1

Insulation of flat roof expanded clay. Is it possible? #Flat Crime

Keramzit was not helped by overdating

What do you think, which element is the most important for a reliable and durable roof?
Share to friends
Alexandra Fedorova

Journalist, author of articles on construction and repair. I will help you understand the complex issues related to the choice and installation of the roof.

Rate author
Add a comment