Old buildings and structures need high-quality insulation. This is due to the fact that over time, the old coating becomes unusable and does not fully perform its functions. In order to ensure reliable thermal insulation of buildings, it is necessary to use high-quality materials. Such material is polyurethane foam. About what qualities it has, how to properly produce insulation of buildings by spraying polyurethane foam and how to care in the future, we will consider further.
What is polyurethane foam as a heater for buildings and structures
Polyurethane foam is a synthetic substance that belongs to gas-filled plastics. It is characterized by a cellular structure and minimal thermal conductivity. Polyurethane foam is obtained by mixing a polyol and a polyisocyanate. In its pure form, these substances are toxic to humans, but during mixing, all negative properties disappear. That is why polyurethane foam is considered an ideal insulation for old buildings and structures.
What buildings and structures are considered old and why
Different types of houses have a different lifespan. As a rule, buildings serve from 50 to 150 years. Old objects are recognized depending on the degree of physical deterioration. The satisfactory condition of the building is considered to be the one in which the wear does not exceed 30%. A higher percentage of wear already indicates the unsatisfactory condition of the building, its dilapidation. The threat of collapse and accident rate are recognized at 75% of physical wear and tear.
Why polyurethane foam insulation is the best solution for insulating old buildings and structures
Old properties need a quality renovation, which also includes reliable insulation of walls, ceilings, floors, roofs and foundations. To update a building or structure, you need to use reliable and proven materials. Polyurethane foam is a high-quality and strong type of insulation, which is ideal for such cases.
Pros and cons
The positive qualities of PPU can be called:
high thermal insulation properties;
durability, which is at least 30 years;
excellent adhesion with any kind of materials;
does not form cold bridges and seams on the sprayed base;
environmentally friendly;
not combustible;
has a low specific gravity;
can be applied to surfaces of any complexity and configuration;
does not absorb moisture;
not susceptible to microorganisms;
can withstand a wide temperature range from -160 to +150 degrees;
can be insulated both inside the building and outside.
PPU also has negative qualities:
does not absorb or reflect sound, as it has a closed cellular structure and low weight;
it can deteriorate if rodents start up in the house, which can easily gnaw through the material;
application to the surface requires knowledge and experience.
What alternatives are there and their comparison with polyurethane foam
Polyurethane foam is the most demanded material, which is not expensive and insulates old buildings and structures with high quality. in addition to it, there are other materials that can also be used in this case:
Fibrous materials with open air pores. This includes mineral and stone wool, glass wool.
Polymer. Styrofoam, extruded polystyrene foam, polyethylene foam products.
Backfilling. Vermiculite, expanded clay or a mixture of clay with sawdust and other ingredients.
Liquid. Ecowool or penoizol.
Technology for applying polyurethane foam to old buildings
Old buildings are insulated with PPU using two methods: spraying and pouring. The first method is good for such buildings that do not have complex ledges, columns, arches. The second is used for structures of complex geometric shapes.
Main differences of technology
PPU spraying allows you to achieve an ideal result by obtaining a seamless heat-insulating layer. The material is securely attached to the base, which cannot be said about other analogues that are used in the process of insulation. If most heat insulators have high thermal conductivity coefficients, then polyurethane foam perfectly absorbs and retains moisture.
The application technology consists in the fact that the components are supplied to the surface in a strictly metered proportion under pressure. Thus, a thin layer of material is obtained, which expands evenly over the entire plane as it solidifies. After 1-3 seconds, a monolithic heat-insulating coating is formed.
What to consider when treating old buildings
All surfaces treated with PPU must be cleaned as well as possible from dirt and dust. If possible, all diagonals are leveled, cracks and irregularities are repaired in the floor. The same goes for walls and ceilings. The smoother the old surface, the more reliable and better the PPU will lie.
It is important to know that old properties are insulated with polyurethane foam in a strict dosage of raw materials. All ingredients must be mixed in compliance with the rules and regulations of such a process. Application on walls, ceilings, floors, roofs and foundations should be carried out with a special spray gun. The feed rate of the components must be uniform.
What old buildings are not desirable to be insulated with polyurethane foam and why
If the building or structure has serious defects that cannot be fully restored, then polyurethane foam is not recommended in this case. The fact is that PPU in this case will need to be applied in several layers, and this is quite expensive, both physically and materially. It is best to use simpler options, such as lukewarm.
What preparatory work is carried out
Before proceeding to the insulation of the old house with polyurethane foam, they analyze the condition of the premises inside and the facade outside. Remove, if necessary, the old insulating layer. Eliminate any damage and uneven surfaces. Check the condition of the plaster. The old and peeling are removed. If the technical condition of the plaster is quite normal, then the insulator is attached to it.
Stages of insulation of old buildings and structures
When insulating old buildings and structures with PPU, certain stages of work must be observed.
Foundation
Before starting work, they completely remove the old surface, clean off all the bumps and level the foundation. Remove dust and dirt from a flat floor. Insulation is applied with special equipment in several approaches. First, a thicker layer is served so that it gently settles and fixes on the surface. After waiting a few minutes, proceed to a new stage of pouring. The number of layers depends on the thickness of the floor and its initial heat retention properties.
floors
The calculation when spraying insulation on the floor is made from the fact that PPU will be applied in a thin layer. Therefore, it is necessary to prepare a thick layer of plywood in advance, which will spread on the floor. It is impossible to use laminate or linoleum, as these materials will not withstand the increased load that will be carried out every day after the repair.
Walls
The walls are covered with polyurethane foam in several stages. The first layer is applied to the surface with a thickness of 3 - 5 cm. After drying, another layer is applied. As a rule, old structures need 3-4 layers of insulation in order to clog and fill with the highest quality all the joints and cracks that can form inside the walls. Between each layer, a certain time must be waited, which depends on the ambient temperature. Usually you should wait 5 - 7 minutes.
Ceiling
The hardest part of the job is the ceiling. Here it is necessary not only to follow a clear application technology, but also to carefully protect your body from the ingress of particles during spraying. A respirator must be worn on the face, and gloves on the hands. It is important to clean the ceiling of dust and level in places where there are irregularities. PPU is applied in the same way as on walls, observing the time interval between spraying the next layer.
Roof
Be sure to apply PPU on the inside of the roof between the joists and the supporting beams. If the attic is old and not residential, then it can not be sheathed with finishing material. If it belongs to the attic part, then additional processing with decorative material is indispensable. It is necessary to use high-quality plywood or drywall. Outside, the roof can also be insulated with polyurethane foam, applying it between the supporting beams and the crate.
Maintenance of polyurethane foam on old buildings
Special care for polyurethane foam on old buildings is not required if you use high-quality materials and follow the technology for applying insulation. Polyurethane foam does not require additional maintenance. The material perfectly tolerates temperature changes and has a long service life.
How long will insulation last on old buildings and structures
The service life of polyurethane foam on old buildings and structures also depends on the quality of the material and the correct observance of the technology of its application. As a rule, the operation of old buildings and structures with PPU insulation does not differ from new ones and is about 30 years. A longer period is not guaranteed due to the deterioration of the structures of the building as a whole.
Polyurethane foam is considered the most suitable material for the insulation of old buildings and structures. This is due to its excellent thermal insulation properties and immunity to moisture, mold and fungi. It perfectly fills the voids and cracks of walls, ceilings, foundations, roofs and attics.
