Building with polystyrene blocks – the latest technology
We are used to seeing polystyrene as packaging, but homes can be built out of it, too.
Image supplied by ICF Southern
Houses built of polystyrene blocks fitted together like ‘Lego’ with space in between to pour concrete have been around since the 1970s. It’s a stunningly simple and remarkably quick building method, only now starting to gain some mainstream appeal in the UK. TV viewers got a glimpse of this innovative technology in Sarah Beeny’s Channel 4 show ‘New Life in the Country.’ Beeny opted for the polystyrene block method – known as Insulated Concrete Formwork (ICF) – to build her new eco-mansion.
What is Insulated Concrete Formwork construction?
The ICF system consists of lightweight blocks (also known as forms) which are usually made from expandable polystyrene (EPS). The interlocking foam blocks are easy to stack – like Lego bricks – to build walls. This cuts out the need for mortar as used in a conventional build. The foam panel framework is reinforced with steel rods or Rebar (reinforcement bar) to lock them into place. Each block can provide up to 1.1 metre2 of wall area. Concrete is then pumped into the cavities.
Image supplied by ICF Southern
The result is a strong, highly insulated and airtight building ready to be finished inside and out. The blocks can be covered externally with brickwork, timber cladding or render and internally with plaster board and plaster.
Anthony Quinn, from ICF Southern, said the innovative technique was suitable for “new builds, renovations, extensions, swimming pools, basements – and many other types of buildings.”
Homeowners are starting to learn the advantages ICF over traditional construction.
Speed of construction
A big plus is the super-speedy build, thanks to the lightweight, easy-to-handle blocks and poured concrete. Because the blocks are easy to cut with a handsaw, building with them is much faster than a traditional masonry build. On straightforward projects, the formwork and pour for a single-storey extension could be done in three or four days. Plus, the construction can proceed in most weather conditions, including rain and frost, so fewer delays
Image supplied by ICF Southern
Simple & easy to understand
The basic structure can be put up by a small team of semi-skilled workers, saving money on time and labour. The concrete is added by a pump, making the process quick and simple. Many ICF firms run training courses for contractors and you can even help build your home if you are a keen DIYer.
With ICF – unlike other types of formwork – the rigid foam forms are retained after the concrete is poured to provide built-in double thickness thermal insulation of the walls. A U-value measures the rate of transfer of heat through a structure. ICF products can provide U-values as low as 0.11 – saving homeowners over 70% on annual heating bills, according to leading supplier Nudura. ICF homes can easily achieve an “A” rating for energy efficiency.
Another advantage is that ICF provides an airtight envelope due to the monolithic, concrete core. This means reduced draughts and cold spots. This airtightness also makes it a good fit for Passivhaus requirements – the gold-standard of energy efficiency. ICF builds usually need a mechanical air ventilation system to supply fresh air.
Superior strength and soundproofing
The strength of ICF comes from the steel-reinforced concrete core. The well-insulated walls mean soundproofing comes as standard. ICF’s solid concrete core is extremely dense which provides an excellent sound barrier to keep out unwanted external noise like heavy traffic. It offers better soundproofing than other quick-to-build systems, such as timber frame.
It’s possible to build in virtually any size and style with ICF. The blocks can be used for creating irregular angles, curved walls, vaulted ceilings and cantilevers for dramatic effect. “The forms are straight, but we use a hot knife to cut grooves and then bend it round to the shape required,” said Quinn. Due to the strength of the steel reinforced concrete core, it’s easy to incorporate spans for large expanses of glazing, such a corner windows or sliding doors. “The biggest span I’ve built is 15 metres and that was without any RSJ,” said Quinn.
Range of cladding materials
Externally, there is a wide choice of cladding materials to achieve your preferred look. Coloured render is a popular choice and often the cheapest option as it can be applied directly onto the polystyrene blocks. For those who want a more conventional finish, options include brick, stone or timber cladding.
Image supplied by ICF Southern
ICF is often marketed as among the safest, most fire-resistant types of construction. This is due to the steel-reinforced concrete core sandwiched between two fire-resistant foam panels. The EPS blocks have been treated with a flame-retardant additive to make them virtually fire-proof. Raw, untreated EPS has the same flammability as diesel fuel and only becomes fire resistant when treated with additive.
While ICF has many benefits, there are also negatives.
One potential disadvantage to building with ICF is the cost. Expect to pay about five per cent more than a traditional masonry or timber frame building. The cost will vary with the price of concrete and the design of the home. That said, it’s quicker to construct and less labour intensive which can bring the cost down compared to some forms of bricklaying. The long-term savings in heating bills should help to offset the initial cost.
While the ICF system sounds simple, you will need a contractor with experience of the technique which can affect the cost. The pour stage is crucial – the ready-mix concrete must flow to all parts of the framework. If things go wrong, it helps to have an expert at hand who will know how to fix it during those crucial minutes before the concrete sets.
With ICF builds, the walls can be very thick, so they take up more space than traditional masonry or wood frame walls. While this can be a plus in some situations, for example near a major road, it may be a problem in smaller projects if you don’t like the amount of valuable floorspace set aside for the rigid foam insulation and reinforced concrete.
Difficult to remodel
ICF homes can be difficult to remodel, for example to add a window or door, as it requires cutting into solid concrete walls. It’s essential to think carefully about the design and consider changes that you might want to make in future if you opt for this building technology. Similarly, plan the electrics and plumbing at the start to avoid adding wiring and pipework after construction which may also involve cutting into concrete.
Is ICF right for your project?
A polystyrene house may sound crazy, but it’s becoming a more common way to build. ICF has many benefits over traditional construction, including build speed, greater energy efficiency, superior strength and comfort. Talk to an architect if you’re thinking of using ICF for your building project. They can give you independent, expert advice tailored to your project.
Image supplied by ICF Southern
Styrofoam™ Homes – InterNACHI®
by Nick Gromicko, CMI®
While Styrofoam™ may be most commonly associated with meat trays and disposable coffee cups, the material is considered by many to be a residential building material.
Communities composed entirely of Styrofoam™ are already a reality in progressively minded Japan. These structures have been approved by Japan’s Land and Transport Ministry, and, with the proper permit, they can be erected anywhere in that country, where they are known as “dome homes. ”
Prefab home manufacturers use the material to construct easy-to-assemble, igloo-shaped modular kit homes. The Aso Farm Land resort village in Kyushu is one notable instance, where 480 Styrofoam™ domes serve as lodging, recreational facilities and retail shops. They are built from 7-inch thick, snap-together wall sections made from a type of Styrofoam™ that is considerably stronger than ordinary packing foam. Dome house kits start at around $30,000, and this price does not include the cost of transport or assembly.
Manufacturers of dome homes boast the following advantages over homes built with wood or metal:
- They do not rust, decay or attract termites. It’s still wise to have an InterNACHI inspector search for such defects.
- They are earthquake-resistant. In fact, models tested by the Federation of American Scientists (FAS) did not merely meet earthquake standards; they remained fully intact after being shaken harder than the strongest earthquakes ever recorded. Styrofoam™ houses can withstand typhoons, too.
- The walls are treated with a flame retardant that emits no toxic fumes during a fire.
- Construction is quick and easy. The prefabricated pieces, which each weigh about 175 pounds, can be carried by two or three people and assembled in a few hours.
- They have excellent thermal-insulation properties, resulting in higher energy efficiency and lower heating and cooling costs. Tests performed by the FAS found that Styrofoam™ can cut heating and cooling costs by 50% to 60%, in some cases.
Even in the United States, where dome homes are still the stuff of hobbits and smurfs, Styrofoam™ homes have passed uniform building code standards, and they represent a growing niche market. In Hawaii, for instance, entire conventional multi-story homes – not Japanese-style dome homes – are being constructed from Styrofoam™. The ceiling, stairs, walls, support beams and roof of such a home are constructed with cement-coated Styrofoam™ and lack straps, tie-downs, nuts and bolts. Even the gutters are cut into the foam, and everything conforms to the building code. According to the manufacturer, these homes are cooler than homes made from conventional building materials, and they cost 10% less to construct.
Another growing market in the United States is homes that are built from a concrete-foam hybrid. The result is a synergy of the insulative capability of Styrofoam™ and the strength of a standard building material. The foam provides continuous insulation, as opposed to traditional insulation that has a break at every wood stud. The technique is about 3% to 5% more expensive for new-home construction.
In summary, Styrofoam™ is emerging as a promising building material for residences.
Bamboo Construction and Inspection
features of material and construction, pros and cons
Many developers prefer to build country houses from concrete blocks. The main advantages of these materials: affordable price, any size is possible (less loading / unloading costs, it is more convenient to build walls), versatility (suitable for both external and internal walls), flexibility (concrete blocks can be cut and sawn, unlike bricks), excellent thermal insulation and much more.
The most popular types of concrete blocks in construction are undoubtedly aerated concrete and foam concrete. Arbolit and slag concrete are less commonly used. Even less so for everything else.
But there is another type of concrete blocks, which is still little known in private housing construction – this is polystyrene concrete. In this article, we will look at what kind of material? Is it possible to build country houses from it? And what are the differences and features it has?
What is polystyrene concrete?
Polystyrene concrete is a type of lightweight concrete. It is a composite building material, which includes cement, porous filler (expanded polystyrene granules), water, and an air-entraining additive (SDO).
By combining polystyrene granules (which are excellent thermal insulators) and concrete, manufacturers have been able to obtain in this material a unique combination of characteristics: rot resistance, hydrophobicity, high load-bearing characteristics, thermal insulation, fire protection, sound absorption, frost resistance and freeze / thaw periods (period exploitation).
Features of the composition
In addition to the above, the blowing agents included in the composition of polystyrene concrete can be synthetic or of natural origin. The second group includes wood saponified resin.
The composition of polystyrene concrete also includes the so-called modifiers (plasticizers). They are called substances, when using which the cement mortar becomes more frost-resistant, strong and plastic (usually slaked lime and liquid soap are used for this).
The list of additives is supplemented with industrial chemicals. Surfactants are designed to increase adhesion between expanded polystyrene granules and concrete mortar. Thanks to this composition, effective wall insulation can be achieved.
Polystyrene concrete blocks today can be purchased at a specialized store and even made independently (this building material is sold in the form of a dry mix packaged in bags). At the same time, it is important to take into account that the formed blocks can only be used 14 days after production.
Types of polystyrene concrete
Block manufacturers classify them based on:
- Density . It varies from 150 to 600 kg/m3. The lower the number, the lower the strength of the material. Thermal insulation also depends on these indicators;
- Compression ratio . It ranges from B0.5 to B2.5. The use of other markings is possible if the requirements of ST SEV 1406 are ignored;
- Frost resistance . The main operational quality is the number of defrosting and freezing cycles.
Polystyrene concrete is divided into three categories:
- heat-insulating – from D150 to D200;
- heat-insulating structural – from D250 to D350;
- structural and heat-insulating – from D400 to D600.
One polystyrene concrete block can replace 20 (!) standard size bricks. Therefore, any houses and structures made of expanded polystyrene are built much faster than conventional buildings.
Panels made of this material are widely used today not only in the construction of house walls, but also in the installation of ceilings, sound and heat insulation of rooms, and restoration of buildings.
Despite the fact that the blocks are very light in weight, developers usually have no difficulty in building additional floors. It is only important that blocks of good quality are used during construction and the floor height standards are observed (we will talk about this below).
It should also be noted that the delivery of polystyrene concrete to the construction site must be carried out by special trucks.
Advantages of polystyrene concrete
Due to the unique composition and technology, expanded polystyrene has the following advantages:
- Low temperature resistance . The material is not afraid of the cold and feels great in harsh Russian winters;
- Impressive and lightweight blocks . That allows you to significantly save on delivery and loading / unloading;
- Almost completely fireproof ;
- No need for thermal bridges . Due to the high thermal insulation properties of the material;
- Budget value and versatility ;
- Durable construction and minimal shrinkage . True, the durability is lower than that of a brick, and the degree of shrinkage depends on the selected weight of the blocks;
- No difficulties in implementing communications ;
- Environmental ;
- Low maintenance .
Styrofoam transport and installation are also easy. This is due to the fact that the product is characterized by lightness and massiveness.
Service life of polystyrene concrete is not limited. Subject to the correct construction algorithm, the house will meet all the requirements.
Disadvantages of polystyrene concrete
Of the minuses of this building material, it is worth noting:
- Reduced vapor permeability . Because of this, increased humidity inside the room may occur;
- Complexity of fasteners . The usual self-tapping screws are unlikely to fit here. Developers most often use anchor bolts, in which the sleeve on the outside resembles a petal;
- Dependence of material quality on production technology . If the latter is violated, polystyrene concrete blocks will not differ in strength. The fact that the products meet the requirements of GOST is evidenced by a certificate. Be sure to check it when buying material;
- Severe damage from prolonged exposure to high temperatures . Polystyrene concrete blocks do not burn, but with prolonged heating they lose their strength;
- Polystyrene concrete is not easy to build . Developers often have similar problems with the installation of door panels and windows (distortions). Due to the period it takes for the material to harden, walls and other structures must be created in one go;
- Defrost and freeze cycle restrictions . The shelf life of the material is long, but by no means eternal;
- UV reaction . Styrofoam balls, under prolonged exposure to direct sunlight, tend to break down.
How to choose high-quality polystyrene concrete?
To purchase a product that meets all regulations, there are several factors to consider. Among them are:
- uniform distribution of granules in concrete mortar;
- foam ball size;
- according to the density of the composition and its weight.
When buying polystyrene concrete, you should pay attention to the manufacturer and the features of the production process. Lack of experience is a good reason to turn to specialists. They will tell you the optimal density and thickness of the panels suitable for the future home.
Features of application in the construction of houses. Block sizes
Before starting the construction of a house made of polystyrene concrete, it is important to determine the size of the blocks.
If the necessary proportions are observed, the cuts of the blocks will turn out to be even and identical. When choosing a size, it is also important to consider that too little weight will mean reduced strength.
A polystyrene concrete house must be built, taking into account the recommended dimensions. The thickness depends on the site:
- external wall – from 37.5 cm;
- wall – from 1.2 m;
- wall at the corner – from 1.8 m.
When creating a polystyrene concrete panel, the composition is placed in the finished formwork. At the same time, there is no need to form additional insulating layers. If the owner decides to make a polystyrene concrete mixture on his own, he will be pleased with the simple mixing algorithm.
In general, the technology of laying blocks from this material is very similar to the technology of building from foam concrete. In order to strengthen the fragile concrete material, it is also reinforced. However, there are also important differences.
The maximum number of floors of a house made of polystyrene concrete should be no more than 2 floors, the height of each of them should be no more than 3 meters. There are no restrictions on roof structures, it can be any pitched roof on truss structures or a flat roof.
According to experts, polystyrene concrete is quite suitable for building small houses in the Moscow region. This can be done by any builder with minimal experience. In order to build a house from polystyrene concrete blocks, any special, special knowledge is generally not required.
There are no restrictions on projects (except for the number of floors). From this material, in principle, it is possible to create architectural and design projects of varying degrees of complexity.
However, it is important to consider the properties of this material. The main disadvantages of polystyrene concrete are considered to be increased fragility and dislike for hot temperatures and the scorching sun.
Therefore, this material in the construction of houses is recommended for use only in small buildings and not in all climatic zones, but only in the northern and middle parts of Russia.
9 tips for building a house from polystyrene concrete: pros, cons, choice
Manufacturers position polystyrene concrete as a strong warm and durable material. Does it have any disadvantages? Is it worth building a house from polystyrene concrete? What features of the material will have to face?
Contents of the article
Recently, the demand for lightweight concrete blocks has increased significantly, catching up and even surpassing the demand for a more traditional building material – brick. There is also competition within the cellular concrete group, and aerated concrete still holds the lead. It is followed by foam concrete, but polystyrene concrete is about to overtake it in popularity. This building material is about half a century old and it has demonstrated itself well during this time: at a low price, it is durable and provides excellent thermal insulation. Cottage with an area of 120 m 2 using polystyrene blocks can be built in just 2.5-3 months. These advantages are worth it in order to take a closer look at the properties of the material and understand whether it is worth building a house from polystyrene concrete, and what features of the material you will have to face.
#1. What is polystyrene concrete made of?
Polystyrene concrete originated as an attempt to produce a building material that would not require additional insulation of the walls outside . Polystyrene balls began to be added to the concrete solution, which provided the material with outstanding thermal insulation properties. Modern polystyrene concrete block contains cement, sand, water, expanded polystyrene granules, special plasticizing and air-entraining additives, and sometimes surface-active substances (surfactants) that increase the adhesion of concrete mortar and foam plastic balls.
Depending on the proportions in which the components for the block were taken, the material can be used for the construction of load-bearing walls, partitions or as insulation. One block of expanded polystyrene replaces 20 bricks, respectively, the speed of building construction increases many times.
#2. Pros and cons of polystyrene concrete
Features of the production technology and composition of blocks allow us to talk about the numerous advantages of the material :
- excellent thermal insulation qualities. According to manufacturers, a 20 cm thick wall will be sufficient to provide the required resistance to heat transfer in regions with a mild climate. In regions with more severe winters, a 30 cm thick wall will be needed, but the most common option in this case is 20 cm of polystyrene concrete and foam insulation. The thermal conductivity coefficient of the material depends on the density, but in any case it is several times lower than that of many analogues;
- excellent sound insulation properties. A wall 20 cm thick is capable of delaying 72 dB of sound;
- The small weight of the blocks and its large dimensions make it possible to significantly simplify and speed up the construction of a house. The need for complex heavy equipment is eliminated. Moreover, it is easy to give the blocks the necessary shape, so in fact you can build a house from them even with complex architectural elements, however, the material consumption will increase greatly;
- high moisture resistance, mold and rodent resistance;
- no shrinkage;
- low foundation load;
- acceptable strength;
- the ability to create a monolithic house from polystyrene concrete, without cold bridges;
- low price.
The main disadvantages:
- low vapor permeability of the material will not allow excess moisture to pass through it from the room, so it is necessary to equip a good ventilation system, otherwise the problem of high humidity and stuffiness inside the house is provided;
- the complexity of fasteners. Ordinary nails and self-tapping screws will hold very poorly in a polystyrene concrete wall, they can literally be pulled out with bare hands, so you will have to stock up on special anchor bolts designed for this material. On the one hand, such a fastener is pulled together with a nut and washer, on the other hand, the outer sleeve opens in the form of a petal;
- The quality of the block is highly dependent on the accuracy of the production technology. If the ratio of concrete and foam plastic granules has been violated, then the strength of the block will be small, and with insufficient adhesion, the granules may even begin to fall out of the block. When buying, always be interested in a quality certificate;
- when exposed to high temperatures for a long time, the foam balls burn out, leaving virtually one concrete frame. Its strength and thermal insulation are not high and do not allow it to be used as an external wall. However, wall cladding with non-combustible materials and high-quality plaster make it possible to protect walls well from fire, and the very ability of walls to withstand high temperatures is worth a lot, so this drawback cannot be called significant;
- the low density of the material complicates the installation of windows and doors. If you do not take into account the numerous features of the installation, then after a couple of years you may encounter loose fasteners;
- walls must be plastered. The layer of plaster inside is at least 20 mm, outside – at least 15 mm, and adhesion with the plaster mortar is not entirely ideal.
The properties of polystyrene concrete make it possible to consider it as a material for the construction of load-bearing walls of a house. It can also be used for the construction of fences, sheds, garages and as a heat insulator.
No. 3. Monolithic houses made of polystyrene concrete
Polystyrene concrete, like expanded clay concrete, makes it possible to build houses using monolithic technology. The composition of the material is still the same, only separate blocks are not made from it – it is poured into the finished formwork, forming the walls of the house.
Advantages of this solution:
- no cold bridges, because there are no seams between the blocks;
- high speed house building;
- minimal chance of shrinkage. Blocks of polystyrene concrete are not capable of shrinkage – it can occur through the use of a solution;
- high strength and durability;
- uniform distribution of the load on the foundation;
- Possibility to embed some communications into a monolithic wall.
The main disadvantage is the difficulty of erecting . Since the walls must be poured in one go, you will need a large amount of mortar and special equipment, so you can’t do it on your own, but you can build a house from blocks yourself.
No. 4. Density, strength and frost resistance of polystyrene concrete
GOST R 51263-99 standardizes the main performance indicators of polystyrene concrete. According to it, brands are determined by density from D150 to D600 where the number is the density in kg/m 3 . The lower the density, the higher the thermal insulation qualities of the material and the lower its strength.
The standard also defines compressive strength classes from B0.5 to B2.5: the higher the coefficient, the greater the load the block can withstand. Also, compressive strength is sometimes denoted through the letter M with a coefficient from 2 to 5. Such a marking is introduced for a material that is designed without taking into account the requirements of ST SEV 1406, its strength is lower.
Frost resistance is determined by the freeze and thaw cycles that the unit can withstand while maintaining its basic performance. For polystyrene concrete, frost resistance ranges from F25 to F100 and increases with increasing material density.
According to the density and a number of indicators depending on it polystyrene concrete is divided into three classes :
- /m*K). Used for insulation of heat-conducting systems, external walls and ceilings;
- heat-insulating structural polystyrene concrete with a density of D250-D350 can be used for thermal insulation of non-load-bearing and self-supporting walls. In some cases, D350 blocks can even be used for the construction of external load-bearing walls, provided that the building is low-rise and the external cladding is light;
- structural and heat-insulating polystyrene concrete grade D400-D600 is used for the construction of load-bearing walls of low-rise buildings (up to 3 floors) and non-bearing walls of multi-storey buildings. Monolithic buildings are also erected from polystyrene concrete of these grades.
For the basement of the house, blocks with a density of D650-D800 would be suitable, but they are not produced by manufacturers, so this element of the house is best built from brick or concrete blocks. It is worth noting that, at their own peril and risk, private builders use the D500-D600 block to equip the basement of 1-, 2-storey buildings and garages, and for the first 10 years of operation there are no problems with these buildings.
No. 5. Types of polystyrene concrete
Polystyrene concrete is produced by manufacturers in the following modifications:
- wall block is used for laying walls and partitions, has dimensions of 588*300*188 mm or 588*380*300 mm;
- baffle block is taller and thinner, measures 588*600*92mm;
- lintel blocks with reinforcement are used, as a rule, for masonry at the locations of window and door structures, have dimensions of 380*300*1300 mm;
- polystyrene concrete solution is delivered to the construction site by special transport, it is necessary for the construction of houses using monolithic technology.
#6. What to consider when choosing and buying polystyrene concrete?
Recently, a lot of low-quality product has appeared on the market, which is caused by the growing demand for polystyrene concrete. Some companies that previously produced foam blocks have now begun to produce polystyrene concrete, and often attempts to quickly please the market lead to a deterioration in product quality. What should I pay attention to and what should I check when buying?
- uniformity of filling with concrete granules;
- uniformity of granules;
- matching block weight to specified density;
- when ordering polystyrene concrete, you need to find out as much information about the manufacturer, so you can and should safely ask where the production facilities are located, be interested in the peculiarities of manufacturing. A normal manufacturer can invite you to production and demonstrate products, and also tell you what wall thickness is better to make, what density of blocks to choose, advise how best to fix shelves, what adhesives and mortars are best to use when laying – in general, you should be answered any question;
- quality certificate is another important point. But even his presence is not always a 100% guarantee of quality. If you are dealing with a distributor and he shows you the quality certificate of the manufacturer, then it does not hurt to check with the manufacturer that he is cooperating with this seller.
#7. Major manufacturers of polystyrene concrete, or who can be trusted?
The choice of manufacturer can be called the cornerstone in building a house from polystyrene concrete. There are many of them in the country, but among the largest enterprises we name the following:
- BlokPlastBeton LLC is a subsidiary of GradStroy LLC, a large manufacturer of building materials. It uses modern equipment, production is carried out in compliance with all technologies. Polystyrene concrete blocks up to D500, heat-insulating slabs and reinforced lintels are produced. Delivery is carried out by road throughout the European part of Russia;
- Polystyrene Concrete Plant LLC was founded in 2001 and over the years has proven itself very well. Floor slabs, wall panels, blocks, reinforced lintels and mortar are produced from polystyrene concrete here. All products are certified. The company is located in the Sverdlovsk region, but delivery is carried out throughout Russia;
- LLC “Polystyrenebeton-SPb” offers polystyrene concrete blocks with a density from D200 to D500 and partitions with a density from D The company has all test reports and relevant certificates;
- TEPLY BETON LLC is a responsible Novosibirsk manufacturer that offers polystyrene concrete in the form of blocks, lintels and mortar for monolithic construction technology. The material is produced with a density of D200-D. Products are widely used by private and large developers;
- LLC “Baushtoff-Polystyrenebeton” is a Krasnodar company that produces blocks and reinforced lintels from polystyrene concrete, the quality of products is constantly improving, production is being modernized.
No. 8. Do-it-yourself polystyrene concrete
You can make polystyrene concrete blocks with your own hands. The more carefully you follow the technology, the more durable and durable products will be in the end. The block making kit is simple. You will need cement, sifted sand, water and polystyrene granules. Instead of concrete, a gypsum mixture is sometimes taken as the basis. Special modifying agents can also be added to the mixture, for example, an air-entraining additive or even tar to improve moisture resistance.
The proportions of the components depend on which block is planned to be obtained and whether the emphasis is on thermal insulation or strength. The larger the piece of cement, the more durable the resulting block will be. The following proportions are suitable for a structural and heat-insulating block: 1 bucket of cement, 3 buckets of sand, 6-8 buckets of polystyrene in granules, a little less than 1 bucket of water. The sequence is as follows:
- water is poured into a concrete mixer or a stationary mixer, all additives and half of all granules are poured so that the cement sticks to the walls less. Water can then be added to achieve the desired consistency;
- cement is added, the mixture is stirred until smooth;
- sand and the remainder of polystyrene are added, everything is well mixed, the required consistency of the solution is dryish, so it will be easier to work with forms;
- mold casting. In their capacity, you can use a metal box, which is independently welded from metal sheets 3 mm thick. You can use a matrix form from old boards, but it is important to grease the form with machine oil. From above, the solution is well rammed, you can turn on the vibration for 2-3 seconds, but no more – prolonged vibration violates the integrity of the blocks;
- The blocks are removed from the metal mold, and from the wooden ones, too, but you can leave them inside the mold for a day. Products are left to dry for 24 hours in a warm place, the temperature is above +15 0 C, you can cover them with plastic wrap. After 4 weeks, the blocks gain the necessary strength for construction.
#9. Features of building a house from polystyrene concrete
Building a house is a complex multi-stage process that requires at least basic special knowledge. In general terms, the construction of a house made of polystyrene concrete looks like this:
- foundation construction . Since the total weight of the structure is small, you can use a columnar, non-buried strip or pile foundation. For complex types of soils, it is better to choose a screw pile;
- construction of walls according to the selected technology: from blocks, with removable or fixed formwork. Building with blocks begins with waterproofing and determining the highest place from which the laying of the walls begins. When laying, verticality and horizontality are strictly observed with the help of fishing line and level. To increase the strength horizontally, you can lay a reinforcing mesh. If blocks with continuous voids are used, vertical reinforcement is performed. The thickness of the mortar joint is no more than 8 mm, it is better to use special glue. Monolithic walls are erected using a removable formwork made of plywood 15 mm thick, it is protected by a polyethylene film from moisture. Plywood is held together by using metal profiles, they are attached to the foundation with self-tapping screws or dowels. Sheets of plywood are attached to the profiles, first they create external partitions, then internal ones. The solution is well rammed when pouring, the formwork can be dismantled after a few days. Brick walls can be used instead of plywood – this is fixed formwork , while the facade cladding is not needed;
- ceiling is made of special polystyrene concrete panels or also by pouring.