Does mineral wool change characteristics when wet?

Rock wool getting wet in the attic can be due to at least a few reasons. Due to a leak or damage to the roof, an incorrectly positioned vapor barrier, lack of ventilation or errors in its execution. Regardless of the reason, the result is the same. Mineral wool is wet. Does this type of cotton wool still fulfill its role? How to dry it?

Mineral wool primarily insulates. In winter it protects from cold, in summer it protects from heat. Increases fire resistance, provides sound insulation, thanks to it the house becomes quieter. When choosing mineral wool, you should bet on products with increased hydrophobization . These are materials from which moisture evaporates very quickly.

Signs that mineral wool is wet may include higher heating bills, increased indoor humidity in the attic, leaks appearing in the eaves or attic, and mold on roof structural members.

It must be remembered that you cannot install wet mineral wool . If it happens that the cotton wool gets wet during transportation or storage, you should first unroll it and dry it thoroughly. Only after it has dried can you begin to install it.

Properties and application features of the material

The main property that determines the effectiveness of a particular insulation is the thermal conductivity coefficient.

It characterizes the heat loss occurring through a layer of material 1 m thick in an area of 1 m2 for 1 hour with a temperature difference on opposite surfaces of 10 ° C.

For various forms of mineral wool, this figure is 0.03 – 0.045 W/(m*K).

A distinctive feature of fiber insulation is the dependence of their thermal insulation properties on moisture content.

When wet, droplets of water envelop the fibers and gradually penetrate into the volumetric structure, gradually displacing air from there.

An increase in the amount of water inside, between the fibers, leads to a sharp drop in thermal insulation characteristics. The situation is further aggravated by the fact that water that gets inside is extremely difficult to remove outside.

The insulation can absorb up to 70% of its mass in water. Naturally, under these conditions, the efficiency of its work will tend to zero.

Despite the criticality of getting wet, the scope of application of mineral wool is extremely wide. When building a house, its use is possible almost everywhere where direct contact with water is excluded:

Hollow walls (frame and brick, made using well masonry technology);
External surface of wooden or brick walls;
Internal partitions;
Floors;
Interfloor ceilings;
Roof.

Protection of wool during installation

To prevent the basalt insulation from getting wet during installation, it is worth protecting the installation site from rain. For this purpose it is very convenient to use inventory scaffolding. And on these scaffoldings, lay boards along the upper rungs of the top row and stretch the film.

It will turn out cheap and cheerful. Not only the building materials will be dry, but also the installers themselves who work on the walls.

To drain rainwater from film roofs on scaffolds, the easiest way is to use 3-4 drainage pipes with a diameter of 110 mm, into which the water accumulating on the film will be drained. This will allow you not to get wet under an unexpected “waterfall”, when water that does not have a drain bends the film and rushes down in an “unfortunate” place.

Reasons for getting wet insulation on the roof

First:

the hydrobarrier or superdiffusion membrane was damaged during installation. That is, the seal of the film is broken with a self-tapping screw or nail. Also, quite often, this occurs due to excessive tension of the hydraulic barrier. According to the standards, it must be installed with a slight sag, so as not to create tension in the material, and so that condensate water can be collected and discharged at the sagging point.

The second reason could be

— lack of gluing at the joints of the canvases, which leads to the penetration of condensate moisture by rising wind currents.

The third reason

is poor fastening at the junction of the chimney and ventilation pipes. It should be noted that the edges of the hydrobarrier must be fixed vertically, upward, to the wall, and a pressure bar must be installed.

The fourth reason

may be the use of low-quality superdiffusion membranes, which are often present in cheap segments.

These are the main reasons that occur when working with hydraulic barriers. But water in the insulation can also appear due to poor installation of the vapor barrier.

This happens especially often when wet work is being carried out in the house in the autumn-winter time, and the roof is already insulated. At the same time, the difference in temperatures inside and outside is noticeable, and all the condensation, rushing upward, gets into the insulation if your vapor barrier is not glued, or is not glued tightly at the joints.

Check the tightness of the films until they are completely closed, be sure to glue the joints and abutments to the walls.

What to do with the insulation if it is already wet?

Take it out and dry it, or buy new insulation. But you can’t leave it wet in the rafters, as mold may form on the wood.

Remember that only professional builders, or the developers themselves who have thoroughly studied these technologies, should carry out insulation work.

. These are materials from which moisture evaporates very quickly.

You must remember that you cannot install wet mineral wool.

. If it happens that the cotton wool gets wet during transportation or storage, you should first unroll it and dry it thoroughly. Only after it has dried can you begin to install it.

Ventilation without errors

One of the more common causes of damp mineral wool is problems associated with roof ventilation. Good ventilation allows air to circulate over the insulation, which allows condensation to systematically evaporate from it

This is why careful design of roof ventilation is so important.

Arkady Shchelyunin, Astrakhan. Question: Good afternoon, it’s raining, autumn. We didn’t have time to make cotton wool on the façade of the expanded clay concrete house. What should we do now? It rains every day. We are afraid that the cotton wool will get wet. Then winter. How to dry it?

Sergey Zaitsev, Moscow, specialist.

Answer: Good afternoon, Arkady. In answer to your question, I can advise you the following. First of all, you are right. If it falls under heavy and prolonged rain, it will absorb moisture. Despite all the advertising assurances of the manufacturers, in the photo with beautiful drops of water on the cotton wool, however, basalt insulation absorbs moisture very well.

Therefore, you can’t get it wet in heavy rain. If during the installation process the cotton wool on the walls gets wet by rain, it’s not a big deal. But if you leave it in the rain for a day, then you won’t be able to really dry it before installation.

So, we do 3 things.

Advantages and disadvantages of floor insulation with mineral wool

This coating does not burn in fire. It can withstand temperatures up to a thousand degrees Celsius and does not lose its properties.

Mineral wool is resistant to high temperatures

Mineral wool can act as a sound insulator.
Mineral wool is a relatively inexpensive insulation product.
This material does not need to be replaced throughout its entire service life.
Simple installation process.

Mineral wool, like any floor insulation product, has disadvantages. One of them is good absorbency. For this reason, experts do not recommend using mineral wool in a damp room, such as a bathroom. However, it is possible to avoid swelling of this coating.

Why does mineral wool get wet?

The thermal conductivity coefficient of mineral fibers is 0.031-0.042 W/m2 *K. This means that a layer of glass wool 5 cm thick is equal to the thermal effect of a meter-long brick wall. But the thermal insulation properties disappear when moisture penetrates the fibers.

Reasons for getting wet:

The waterproofing membrane was damaged when laying insulation. They pulled the canvas too tight and accidentally pierced it with a nail or self-tapping screw.
The film joints were not taped. As a result, condensation penetrates into the mineral wool fibers.
The waterproofing near ventilation and chimneys was not fixed tightly enough.
A low-quality diffuse membrane was used.

Risk of getting wet: the dangers of damp insulation

Wait for the wet roof insulation

will dry on its own - a dangerous misconception. Wet mineral wool does not retain heat. In addition, it becomes a source of unpleasant odors, the spread of mold and bacteria. Well, and the “cherry” in the troubles of the roofing pie: wooden rafters are destroyed, metal structural elements rust at an accelerated pace. The result is a major roof repair.

To avoid problems, check the condition of the insulation:

if there are streaks or drops on the walls of the attic;
cracks have appeared on the roof, the roofing elements do not fit tightly;
In places where snow accumulated, the roof sagged.

Wet business: what to do with wet insulation

Having discovered that the thermal insulation is wet, there are two options for the development of events. If the fibers are wet only on top and in a small area, it is possible to dry this area. This requires two conditions: a draft and clear, warm weather.

URSA experts recommend replacing insulation that is wet through. The main thing is to avoid making the same mistakes when installing new material.

How to fix the problem and keep the insulation dry

To protect your newly insulated roof from getting wet, consider these professional tips:

It is advisable to carry out installation in dry weather;
before installing mineral wool, cut the waterproofing film into layers of the required length;
Having fixed the insulation, immediately cover it with a protective membrane;
glue the joints of the film, secure it to the rafters with a construction stapler;
Walk only on the boardwalk so as not to tear the waterproofing.

You can select a special insulation material for pitched roofs and waterproofing for it at https://www.ursa.ru/construction-solutions/skatnie-krishi/.

Proven materials, competent installation and the roof will remain dry in any weather!

Question:

Hello. My insulation material got wet on the roof - . The company's builders say that it is rock-solid and it will dry out quickly. Is it true? What could be the consequences of getting Rockwool, a thermal insulation material, wet?

Konstantin

Answer:

Hello, Konstantin.

The insulation material could become wet for the following reasons:

1. Leaking roof covering.

2. The integrity of the vapor barrier layer has been compromised.

It is true that mineral wool can dry out after being moistened, but certain conditions must be observed. It is necessary to ensure that air can move freely in the under-roof space. It is thanks to this that moisture will be removed from the insulating material. To achieve this, you need to make a ventilation gap, which can be either single or double, it all depends on the type of structure.

Based on our experience in thermal insulation, we can say that a properly installed and well-ventilated under-roof space will help dry the wet insulation and the already dried material will not lose its thermal performance.

You need to find out why it got wet and eliminate the cause. If everything is clear about the leak, then most cases of the thermal insulation material getting wet is the lack of a vapor-proof layer or lining when installing the thermal insulation. A common mistake is poor sealing of seams with double-sided tape or failure to glue overlaps at all. When laying vapor barrier films, it is necessary to glue all 10-centimeter overlaps with double-sided tape.

Don’t forget to inspect the rafter system to see what happened to it when it got wet. Wood structures also dry out, but not as quickly as mineral wool insulation. To ensure better preservation of the rafter system, all wooden parts must be treated with an antiseptic; it will help the tree not absorb water so quickly.

Construction forum

What to do if mineral wool insulation gets wet? Will the insulation retain its properties if it gets wet after drying? These questions often arise when, for some reason, the insulation is wet and obvious traces of wetting and even absorbed water are visible on it. We answer. Mineral basalt wool ROKVUL, IZOROK, KHITROK, IZOMIN, ISOVOL and other similar type of insulation are produced HYDROPHOBIZED, that is, they are impregnated with a binder that has the property of repelling water and, in principle, water that gets on the insulation rolls off and is not absorbed. If the mineral wool is still saturated with water, then the moment is more serious, but not fatal! If you provide sufficient conditions for the insulation to dry!!! then your basalt wool, and Ursa, Uteplit, Izover fiberglass, WILL DRY and will work like normal thermal insulation. Wet insulation loses its properties if the water-saturated areas of the insulation are exposed to negative temperatures... it will simply turn into ice and everything!!! Your structure will freeze. Therefore, it is necessary to provide conditions for drying (most likely this is in the warm season or spring). Or you need to change the insulation if the structure is frozen and there is no time to wait for the heat to dry out the insulation. We remind you that the insulation of their extruded polystyrene foam PRIMAPLEX, PENOPLEX, TEPLEX does not get wet and is not afraid of the external environment.

Protecting wool from rain before installation

We store the finished cotton wool in bales right next to the walls, preferably indoors. In this case, it can be supplied for mounting on walls in windows of the first or second floor, as is more convenient.

Next, if the wall is blank, we make a temporary canopy next to it from boards and film. Nothing global is needed, the main thing is that the water flows onto the ground and not onto the cotton wool. Although it is packed in film bales, this is not protection from heavy rain.

Further, we understand that in heavy rain, especially during prolonged autumn storms, all the water is underfoot, the earth does not have time to absorb such an amount of water. We do not place cotton wool in bales or sheets on the ground, even under a canopy. It is best to use the most common wooden pallets. Their height, 15 cm, is enough to prevent the cotton wool from getting wet from the ground.

In what form is it produced?

Basalt wool is produced in rolls, slabs and cylindrical shapes. The softest material is contained in rolls, in slabs of medium and high hardness. And the cylindrical shape is intended for insulating pipelines.

Double insulation of stone wool - foiling. Stone wool covered with foil is universal; it not only does not release precious heat, but also reflects it and directs it back into the room.

When is a ventilation gap needed? ventilation gap in a frame house

So, if you are thinking about whether a ventilation gap is needed in the facade of your carcass house, pay attention to the following list:

When wet If the insulation material loses its properties when wet, then a gap is necessary, otherwise all work, for example, on insulating a home, will be completely in vain
Steam Permeation The material from which the walls of your home are made allows steam to pass through into the outer layer. Here, without organizing free space between the surface of the walls and insulation, it is simply necessary.
Preventing excess moisture One of the most common questions is: is there a need for a ventilation gap between vapor barriers? If the finish is a vapor barrier or moisture-condensing material, it must be constantly ventilated so that excess water is not retained in its structure.

As for the last point, the list of similar models includes the following types of cladding: vinyl and metal siding, profiled sheets. If they are tightly sewn onto a flat wall, then the remaining accumulated water will have nowhere to escape. As a result, materials quickly lose their properties and also begin to deteriorate externally.

Is there a need for a ventilation gap between siding and OSB?

When answering the question of whether a ventilation gap is needed between the siding and OSB (from English - OSB), it is also necessary to mention its need. As already mentioned, siding is a product that insulates vapor, and the OSB board consists of wood chips, which easily accumulate residual moisture and can quickly deteriorate under its influence.

Additional reasons to use a ventilation gap

Let's look at a few more mandatory points when clearance is a necessary aspect:

Preventing the formation of rot and cracks The wall material under the decorative layer is prone to deformation and deterioration under the influence of moisture. To prevent rot and cracks from forming, just ventilate the surface, and everything will be fine.
Preventing condensation The material of the decorative layer can contribute to the formation of condensation. This excess water must be removed immediately.

For example, if the walls of your house are made of wood, then an increased level of moisture will negatively affect the condition of the material. Wood swells, begins to rot, and microorganisms and bacteria can easily settle inside it. Of course, a small amount of moisture will collect inside, but not on the wall, but on a special metal layer, from which the liquid begins to evaporate and be carried away with the wind.

Remove, dry, install

It’s worse when the mineral wool that is already installed in the attic gets wet. Then it needs to be dismantled, dried and installed again. This is very important, because wet mineral wool loses its properties. The drier it is, the better its parameters. Water that penetrates the cotton reduces its effectiveness. Even a small amount of water can significantly reduce its parameters. Wet mineral wool does not fulfill its purpose. Instead of insulating, it conducts heat. If there is wet mineral wool in the roof, thermal insulation is reduced and heating bills increase. Wet insulation also has a negative effect on wooden structures, it contributes to the moisture of the rafters, and, as you know, dampness is the main enemy of wood.

Protection of basalt insulation after installation

Well, of course, immediately after installing a section of basalt insulation on the wall, this section is closed. This protects the already installed wool on the walls from slanting rain.

The membrane itself does not tolerate ultraviolet radiation very well, so you should not hesitate with the subsequent decorative coating - siding or any other that you have chosen.

If you are not doing a ventilated façade, but rather, then there is no need to worry too much here. The plaster layer will easily cover the cotton wool, but it will still get a little wet during the installation process.

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Thermal insulation of an attic roof means three benefits in one solution. Firstly, the house becomes noticeably warmer. Secondly, heating costs are reduced by 30-50%. Well, and thirdly: a residential floor appears. They finished the walls and got cozy rooms under a roof instead of a cluttered attic.

A popular roofing insulation is mineral wool. A material with excellent performance characteristics, non-flammable and affordable.

When is a ventilation gap still necessary?

In what other cases will you need a ventilation gap between the wall and the decorative covering:

The material of the decorative layer promotes the formation of condensation.
The wall material under the decorative layer can deteriorate from moisture (rot, cracks, etc.).

Otherwise, all the moisture that will condense on the inner surface of the corrugated sheet will be absorbed, which will be destroyed as a result.

In the case of a ventilation gap, moisture, of course, condenses on the inner surface of the profiled sheet - this is metal. But it does not have direct contact with the surface of wooden walls. And the air current that is present in the ventilation gap carries away this moisture in the form of steam and removes it from the space between the decorative layer and the wall.

Consider which of the above cases is yours and choose whether you need a ventilation gap or not. See what kind of wall material you have.

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The ventilation gap in a frame house is a point that often raises many questions among people who are involved in insulating their own home. These questions arise for a reason, since the need for a ventilation gap is a factor that has a huge number of nuances, which we will talk about in today’s article.

The gap itself is the space that is located between the sheathing and the wall of the house. A similar solution is implemented using bars that are attached on top of the wind barrier membrane and on the external finishing elements. For example, the same siding is always attached to bars that make the facade ventilated. A special film is often used as insulation, with the help of which the house, in fact, is completely wrapped.

Many will rightly ask, is it really not possible to just take and attach the sheathing directly to the wall? Do they just line up and form an ideal area for installing sheathing? In fact, there are a number of rules that determine the necessity or unnecessaryness of organizing a ventilation facade. Let's figure out whether a ventilation gap is needed in a frame house?

Hardness index

The insulation is produced in three levels of rigidity:

Soft stone wool is made from the finest fibers. It has a huge number of cavities that hold air. Soft stone wool is used to insulate building facades, frame walls, and roofs. That is, in places where there will not be much mechanical impact
Medium hardness wool is made from medium fibers, they are stiffer. This type of insulation is used to insulate ventilation ducts, that is, where there is a strong air flow
Thick and durable fibers of rigid stone wool. This insulation is used for heavy loads. It can be used to insulate walls at an intermediate stage of construction, before reinforcement, concrete screed, etc.

When is a vapor barrier necessary?

It is definitely enough to simply formulate the condition of whether a vapor barrier is needed. When insulating with mineral wool, protection from water vapor will be needed when there is a possibility of contact with air coming from the room.

To ensure effective operation, each layer of the thermal insulation “pie” must allow air to pass through to one degree or another. In the direction from room to street, this ability should increase.

Thus, warm air from the room very slowly seeps between the fibers, displacing cold air from there.

These can be vertical frame posts, floor joists or rafters. A wind-waterproofing barrier is installed on the outside (external) side, protecting from the effects of precipitation and strong direct wind.

This scheme is valid when constructing frame walls, floors, attic roofs, and the ceiling of a residential floor in the presence of a cold attic above.

Internal partitions and ceilings between living spaces require a slightly different approach. In this case, humid air can penetrate the mineral wool from any side. To maintain the thermal characteristics of the structure, a vapor barrier is installed on both sides.

Excess moisture is removed through a ventilation gap left under the outer decorative facade.

The nuances of thermal insulation of a flat roof

The insulation of flat roofs is carried out according to special rules that differ from the principles of thermal insulation of pitched roofs. The analogy can be traced only in the sequence of laying the layers of the roofing pie. Flat structures do not have rafter systems, among the elements of which it is convenient to place a thermal insulation layer.

There is nothing to nail the sheathing to, forming a ventilation gap to ventilate the components. Instead of channels for ventilation, if necessary, original vents are created due to partial gluing of the coating to the underlying base.

According to building traditions, a flat roof roofing pie is constructed by sequentially placing its components on top of each other. Traditional components include:

Vapor barrier. Acts as a barrier to household fumes. Located on the side of residential, commercial, etc. premises.
Thermal insulation. Prevents the passage of heat waves from the inside to the outside of the building and in the opposite direction. At the same time, it copes with the duties of a barrier to sound vibrations.
Waterproofing. Covers the thermal insulation from the outside, protecting it from atmospheric water. It is laid in 4-6 rows, depending on the size of the roof slopes that direct water to the water intakes, and on the technical characteristics of the roofing material. The outer layer of waterproofing of a conventional roof serves as the finishing coating. When constructing ballast roofs, gravel, soil and vegetation layer, paving slabs, etc. are laid on top of the waterproofing.

Violation of the sequence of layers and installation rules ends in failure for owners, who are forced to shell out considerable sums for repairs or even for a total reconstruction of the roof.

Note that the indicated layers, together with their laying sequence, are used only if it is necessary to retain the heat obtained by heating the premises.