Advantages and disadvantages of roof insulation with stone wool, methods of laying the product on floors of various structures, advice on the choice of components, the sequence of operations. Roof insulation with stone wool is the creation of a protective shell on the batten of a sloped roof or on a flat floor to keep warm in living quarters. Fibrous material performs well its functions only in combination with waterproofing and vapor barrier products that protect it from external influences. In the article you can find all the information about the rules for the formation of the insulation "pie", which will help to avoid mistakes during installation.
Features of thermal insulation of the roof with stone wool
If you plan to reliably insulate the house, then you cannot do without roof modification. The problem will be solved by stone wool - a fibrous material produced from basalt rocks. The threads of the product are short and fragile, and so that they do not crumble, binders, often containing phenol-formaldehyde, are added to the composition. The space between the fibers is saturated with hydrophobic and inert components that enhance the performance of the blocks.
The properties of the sheets depend on the location of the fibers in the insulation. In total, there are three types of materials - with vertical, horizontal and randomly located threads. The first two increase the strength of the product, the last one affects the thermal insulation characteristics.
The product is sold in rolls up to 50 mm thick. Thicker specimens are available as rectangular slabs. The sizes are chosen depending on climatic conditions. Usually, for not very cold winters, a thickness of 150-200 mm is sufficient. Sheets can be stacked in 2 rows, and the seams of the upper and lower layers should not coincide.
Stone wool is very dense, so its thermal conductivity is lower compared to other mineral samples. The material ensures long-term operation of the roof without repair and is often used for thermal insulation of the roof of capital buildings. For thermal insulation of the ceiling of auxiliary buildings, other products are used, the restoration of which requires little money.
For sloped roofs, slabs with soft ends are most suitable so that they self-adhere between the beams. Samples with uniform stiffness can fall out of their original place. Often they are held in a more reliable way - with the help of a crate, which is fixed to the bottom of the rafters. A flat roof is covered with high density slabs without soft edges. Such panels do not deform or bend.
Stone wool panels are quite heavy, so roofs must be strong. If the work is carried out at the initial stage of building a house, it is necessary to calculate the cross-section of the rafters, taking into account the load from the insulation. When finalizing the roof of operated houses, it is better not to use sheets that are too dense.
Stone wool fibers can harm the body, so you must follow the simplest safety rules:
- Wear protective gloves, goggles, a respirator, and long-sleeved clothing. Change when you're done editing.
- Keep insulation out of the reach of children.
- Be careful not to scatter fibers throughout the yard. Collect waste immediately after use.
When forming an insulating layer, a vapor barrier must be present, which will protect the coating from getting wet.
Advantages and disadvantages of stone wool coating
Basalt insulation has excellent characteristics that distinguish it from materials of a similar composition.
Stone wool is appreciated for the following qualities:
- Possesses high rates of thermal insulation.
- It does not lose its properties in winter and summer, which is especially important for roofs.
- The budget price allows consumers with any income to buy it.
- Has the lowest moisture absorption of all types of mineral wool.
- Sheets of the product are easily cut off.
- Cotton wool does not burn and does not emit toxic substances when exposed to high temperatures. It is used to insulate fire-hazardous buildings.
- The coating has sound insulating properties.
- The service life is unlimited.
- Low weight allows you to insulate dilapidated buildings.
- The insulation is environmentally friendly.
- Rodents do not live in compacted fibers.
- Basalt wool can be used to cover a roof made of any material.
- It is resistant to mildew and mildew.
- Moisture that gets inside quickly evaporates.
- The insulator is produced in a wide range of products - in slabs, rolls and mats, which allows you to select the optimal samples for a particular roof. Rolls and mats are lighter, sheets are dense and can withstand heavy loads.
Even such a modern insulation has disadvantages:
- Cotton wool tolerates moisture worse than hard boards. If the installation is performed poorly, it quickly loses its properties.
- The material has little tensile strength.
- The product must be used in combination with waterproofing and vapor barrier membranes.
Roof insulation technology with stone wool
Roof insulation options depend on its design. Flat roofs are insulated with rigid panels so that they can be walked on. Pitched ones are modified with blocks of low density, which are cheaper. Together with insulation, they also buy steam and waterproof products.
The choice of stone wool for the roof
Stone wool is used in conditions of extreme heat and frost, which only high-quality products can withstand. When buying, remember our recommendations:
- On a pitched roof, buy sheets, the dimensions of which allow them to be stacked between the rafters "oversight". Do not use narrow blocks - slots increase the heat loss of the building. Install only dry plates. Wet elements will cause woodwork to rot. The insulator should be 30 percent thinner than the beams.
- If you require insulation with a thickness of more than 150 mm, stack the sheets in two rows.
- In stores, look for goods with the following designations: P-75 - for the roof of the attic, P-125 - for flat ceilings.
- Please check the storage location of the item before purchasing. It absorbs moisture well, so it should be kept in a dry place. Material stored outdoors must be wrapped in plastic wrap.
- Discard wet cotton wool. After drying, the heat-insulating properties of the fibers do not return.
- Buy an insulator from one manufacturer, because the characteristics of products manufactured at different enterprises differ.
- Previously used stone wool has worse performance than newer wool.
- The chance to buy a fake in company stores is very low.
- The following factors affect the price of the insulation: the manufacturer, the density of stone wool for roof insulation, the type of binder, the rock from which it is made, the presence of additional layers of coating. Do not buy sheets that are too dense for the attic roof, you can get by with less dense and cheap ones.
- Check the manufacturer's recommendations for product use. The scope of application of the product is always indicated on the label.
- Basalt wool "Rockwool", "Ursa", "Technonikol" is considered to be of the highest quality. If you have a choice, buy products from German companies - this country has the strictest rules for obtaining certification for thermal insulators.
Insulation of a pitched roof
The composition of the stone wool coating for a sloped roof does not differ from other types of roofing - the insulation is placed between the vapor barrier and the waterproofing. However, installation has its own characteristics. In most cases, the product is fixed between the rafters, less often on the beams from above or below.
It is advisable to modify the sloped roof at the initial stage of building a house in order to simultaneously insulate the walls. In this case, it is possible to arrange the rafters with a pitch of 58 or 118 cm and not cut the sheets before installation.
If the work is carried out in the fall, start the installation with waterproofing and covering the roof with cladding material. Put the cotton wool in the second place, from the inside of the attic. In this case, it will not get wet in the rain. From the side of the attic, the ceilings of buildings that have been in use for a long time are also insulated.
Let's consider in detail the option in which the panels fit into the frame. The work is performed in the following sequence:
- Cover all timber frame structures with fire retardants, antiseptics and insect repellents.
- Attach the slats to the rafters from the attic side with a pitch of 200-300 mm, which will support the insulation.
- Measure the distance between the beams and cut the blanks from the results. The blocks must fit snugly into place.
- Fill the space between the power elements with the panels, check that there are no gaps. Seal the cracks with polyurethane foam if necessary.
- Cover the outside of the rafters with a waterproofing film with an overlap of 15-20 cm over the adjacent cuts. It is important to correctly orient the membrane - it allows moisture to pass through only in one direction. The film does not interfere with the movement of moist air from the stone wool to the outside. The canvas should hang with a little slack.
- Check for a 10-15 mm gap between it and the insulation so that the pores of the membrane do not close.
- Seal the joints of the panels with reinforced tape. The moisture that remains on the film is removed by an air stream moving along the gap under the roof cladding. To create a draft in the lower part of the roof and near the ridge, make holes.
- Fit the battens and counter battens under the roof cladding. Make sure that there is a gap of 50 mm between the film and the roof covering for ventilation. Cover the roof with tiles, slate, or other material.
- Cover the cotton wool from the inside with vapor barrier films with an overlap of 15-20 mm on adjacent pieces and on the walls. Glue the joints with reinforced adhesive tape. The film will protect the fibers from the humid air entering the attic from the lower rooms. The best option is to use a reinforced three-layer membrane or a product with a metal layer.
Insulation of a flat roof
A flat roof is rarely found in private housing construction. The reason is precipitation, which sloped structures better divert from the upper part of the house. It is advisable to insulate such floors with plates of maximum rigidity. They are able to withstand the point loads that occur during construction and distributed loads such as wind or snow.
Insufficiently dense sheets bend, which worsens the thermal insulation properties of the material and disables the vapor barrier coating. To increase the compressive strength of the cotton wool, it is covered with an additional layer - a screed, but this increases the load on the roof.
There are several options for insulating a flat roof with stone wool. The classic one-layer method involves laying the panels in one row.
The work is performed in the following sequence:
- Free the roof from foreign objects, clean debris.
- Seal the cracks with cement mortar. Knock down the ledges. Prime the surface.
- Fill the roof with cement mortar, ensuring a slope of 2-5 degrees. Check the flatness of the screed. To do this, place a long ruler on the screed and make sure there are no gaps underneath. The presence of voids under the insulation leads to heat loss. After the screed has dried, you can continue working.
- Waterproof the surface in a manner that is appropriate for the design. Reinforced concrete floor slabs are protected with coating agents. Usually bituminous mastic is used for this purpose. In the presence of corrugated board, classic polyethylene is used.
- Cover a small area of the roof with bitumen and immediately place a sheet of cotton wool on it. Glue the rest of the panels in the same way, pressing them tightly together. Do not line up the sheets.
- The samples are attached to the iron cladding with telescopic dowels with wide heads.
- Waterproof the insulation with roofing felt. To increase the strength of the roof, it is recommended to cover the blocks with a cement-sand screed before creating moisture protection.
A two-layer thermal insulation system is created from several rows of wool of different hardness. Thick slabs with a density of 100-125 kg / m are laid first3, on top - panels with a density of 180-200 kg / m3… Insulation cake turns out to be cheaper than from a material of the same hardness.
Surface preparation and fixing to the base is performed in the same way as in the previous case. The sheets of the second row are glued to the first bituminous solution. They should overlap the joints of the lower layer. From above, everything is covered with a roll-up waterproofing material.
Typical mistakes when insulating a roof with stone wool
When revising structures, mistakes are sometimes made that worsen the thermal insulation of the building. For example:
- Use of sheets with sizes and weights that are not intended for a specific location. Roll wool that is placed between the rafters and is not secured can slip off.
- Insufficiently dense panels mounted on operated roofs are deformed from mechanical stress, which causes the integrity of the entire layer to be disrupted.
- Violation of the installation technology leads to the formation of cavities and the penetration of cold.
- Careless laying of sheets causes destruction of the coating.
- Incorrectly calculated layer thickness.
How to insulate the roof with stone wool - watch the video:
The use of stone wool is considered the best of all possible options for insulating the roof: the method of thermal insulation is very simple and does not require the participation of construction teams. The main condition for achieving a good result is the fulfillment of all the requirements of the panel mounting technology, so as not to negate what has been done.
