Polyurethane foam is one of the common thermal insulation materials for thermal insulation of the roof when building a house. It can be applied to the surface by a sputtering method or casting. The material can be used to create a thermal insulation layer in roofs, complex configuration. Spray polyurethane foam on the inside of the roof slopes and applying a material such as liquid rubber outside requires some knowledge in the field of construction.
Polyurethane foam: the material characteristics
Polyurethane foam is a foamed plastic with a fine-mesh structure filled with gas. Most of the material is a mixture of carbon dioxide and air.
Distinguish 4 types of polyurethane foam:
- Elastic polyurethane foam. Constructed on the basis of plastics with a density less than 20 kg / m3. The openness of the cells allows air to move freely. In addition, the flexible polyurethane foam is well bent and can recover its original shape. With it can perform both internal and external insulation roof slopes.
- Rigid polyurethane foam. It is made of foamed plastic and has closed cells. The density of this type of polyurethane is 30-60 kg / m3. In the material composition includes about 3% solids, whereby the foam is not deformed and is highly resistant to various damages. For roofing recommended to use polyurethane foam density of 40 kg / m3.
- Date PPU. A material with open cells and a density of 20-30 kg / m3. It is used mainly for thermal insulation of the roof and walls of the house inside. The use of this type of foam requires the use of steam and water-proof materials.
- The liquid foam. Insulation is used to fill different niches and voids. The density of the material is less than 20 kg / m3. The liquid material is typically used for soft roof.
Liquid polyurethane rubber can be divided into 3 groups: single-component and bicomponent polymer-bitumen composition. Most often used second and third embodiment of the liquid rubber.
Popular brand liquid rubber based foam: UreFlex, CyberSkin-C, CrystalFlex-70 and others.
Price will depend on the density of insulation material, thickness and complexity of the installation work.
Advantages and disadvantages
Polyurethane foam has a low moisture permeability. It should be noted that the greater the density of insulation, the less it absorbs moisture. The structure includes flame retardants and halogen - substance, provide fire resistance and slow down the process of ignition and combustion. It should be noted that the material burns only at an open fire.
Other advantages of the material:
- A low thermal conductivity coefficient
- Completely covers all cracks and small cracks
- No special surface preparation for application of the insulation
- The material is not susceptible to rot and mold and mildew
- high adhesion
- waterproof insulation
- PPU is not subject to corrosion
- Is not exposed to different chemicals
- Education seamless layer, which prevents the formation of bridges
- Long service life (about 30 years)
In addition, the heater is harmless and non-toxic. Polyurethane foam is lightweight due to this there is no additional load on the roof.
In addition to the positive characteristics of foam has a number of drawbacks:
- High price
- low vapor permeability
- Destruction by ultraviolet radiation
In addition, you must use special equipment for applying heat insulation. It is possible to rent or buy.
The destruction of the material when exposed to sunlight extends to 1-2 mm. It is provided that the foam was not coated with a protective layer.
However, the positive properties of the polyurethane foam is much more than the negative. Therefore, many builders choose it for warmth not only the roof, but the walls of the facade and so on. D.
Preparatory work
Before starting the installation, you need to prepare the surface and test the functionality of the equipment.
You must thoroughly clean the surface from dirt, debris, mold. Roof must be dry or else polyurethane otherwise be poorly connected with the surface and the defects remain in the result.
If there are any cracks, holes larger than 6 mm, they must be repaired.
Preparatory works are also in the arrangement of wooden crates, while its height should match the height of the thermal insulation material layer.
It is important to test spraying to make sure that the insulation material has a normal structure. If necessary, adjustments are made and carried out repeated spraying.
Materials and tools for spraying
A device for spraying polyurethane foam can be rented or purchased. However, the second embodiment will be costly. The equipment consists of the following components:
- Cylinders with the contents (polyol and isocyanate)
- Spray Gun
- hoses
- nozzles
- grease
The roof should be well insulated, and quality otherwise it is likely that it will start to flow, and as a result the house appear wet and rooms will be felt high humidity. It is also important to choose high-quality material.
Methods of spraying polyurethane foam: step by step guide
Mounting of roof insulation structure can be carried by two methods: spraying or pouring.
spraying technology is as follows:
- Polyurethane foam is poured into the special equipment in liquid form;
- A first insulation layer is applied with a tight seal voids and cracks. Work is performed from the bottom to the top. Particular attention should be given to the deposition of the joints and corners of the roof structure;
- Overcoatable PUF. This will improve the thermal and sound insulation characteristics of the roof. For qualitative recommended insulation layer should be 5-8 cm.
spray polyurethane foam technology - Waiting until complete solidification material should be cut off the projecting portions of insulation;
- In the final step, you finish. It recommended to apply the plaster or paint for extra protection.
During the installation work on the roof insulation is necessary to observe safety precautions. All work must be carried out in a protective suit and mask.
sputtering method differs from the fill that the polyurethane foam is applied to the surface in a foamed state with a high pressure using special equipment.
It is important to know the basic features of spray technology and comply with the instructions, to exclude possible errors during the thermal insulation of the roof.
Roof insulation pouring method
In this manner, fill the free cavity structure legs. Liquid insulation fill slopes with the help of pumping equipment. Polyurethane foam roof insulation is performed in several layers. First, a thin first layer, then the next. It is important to comply with breaks for drying. Such roof insulation method has some advantages, namely: the speed of performance, simplicity, easy regulation of thickness of the heat-insulating layer.
Polyurethane roofing installation should be performed at a positive temperature of less than 15 degrees, and in dry weather.
Pouring polyurethane technology commonly used in the restoration of the old roof structure, if necessary relief process of any complexity, and also if there are arches, protrusions, columns and so on. D.
Technology soft roof liquid rubber
It is important not only to insulate the roof inside, but also apply polyurethane waterproofing material on the outside to protect the structure from various adverse weather conditions. For this purpose the liquid rubber-based polyurethane.
Application of the liquid rubber can be carried out manually or by means of special devices.
Before applying liquid rubber surface should be cleaned of debris and dust. It should be remembered that the installation of the waterproofing should be done in dry weather.
Milestones soft roof liquid rubber:
- Primed surface. Apply primer to the roof thoroughly, leaving no gaps. This applies particularly to the joints and corners;
- Application of the material. To uniformly apply the liquid rubber, it is necessary to observe a right angle between the surface and the spray;
- The application of the next layer. The number of layers depends on the climatic features of the terrain. Usually enough 2-3 layers.
Feature spraying technique is the application of subsequent layers only after the final drying of the first.
Sprayed the roof can not only protect the surface from moisture, but also from other negative phenomena. The execution of works is better to entrust a qualified master, but you can make your own work clearly following instructions.