
2023 Author: Philip Bishop | [email protected]. Last modified: 2023-05-24 22:24
- What is the harm caused by condensation?
- Causes of problems
- The roof is not insulated well enough
- Poor vapor barrier
- If the attic is not ventilated
- Lack of ventilation of roofing materials
- Violation of technology, substandard materials
- How to deal with condensation?
The question of how to deal with condensation on the roof is very relevant, because excessive moisture can seriously damage the building. The boards will start to rot from it, a fungus may appear, which eventually gets into the room, moreover, moisture creates unnecessary dampness. It is quite possible to get rid of it if the roof is properly protected.
What is the harm caused by condensation?
Condensation on the roof seriously damages a variety of insulation materials such as mineral wool. From moisture, it not only turns into lumps, but also loses its properties. Wet cotton wool will not last more than two years, although in dry conditions it will not have to be changed after 20 years.
Roof repairs are quite expensive. Due to moisture, supporting structures can suffer, for example, the logs and the roof will sag, begin to leak or collapse. That is why it is necessary to deal with condensation immediately after its detection, without postponing the solution of the problem until later.

If there is little moisture, it can cause fungus that eats into the boards, causing them to rot in a few years. If the condensate does not go anywhere, it can form large puddles that can flow through the ceiling. Moisture can penetrate the insulation and ruin it. The house will become damp, it can become much colder, especially such a problem is inherent in rooms with a metal roof.
Causes of problems
Before starting the difficult struggle with the phenomenon, you need to understand why condensation forms under the roof. The main reasons may be the following factors:
- Ceiling slabs are poorly insulated, the roof is leaky and has large gaps.
- Insulation was not installed or it was done incorrectly.
- The space under the roof or attic does not have sufficient ventilation and there is nowhere for moisture to evaporate.
- Thermal insulation materials were installed incorrectly or not at all.
- Low-quality materials were used or the technology was seriously violated during the installation of the roof.
One of the listed reasons is enough for condensation to appear under the roof. Therefore, it is important to calculate the cause and eliminate it, otherwise the problem will not be solved.

The roof is not insulated well enough
Quite often, the formation of condensation in the roof is associated with its poor insulation. Usually the problem is caused by the insulating material being too thin and moisture seeping into the floor area. However, the layer can be of sufficient thickness, but its quality is poor. In this case, at subzero temperatures outside, warm air will leave the room. In the place of collision of a warm and cold stream, drops of water will settle, which first falls into the attic, then can penetrate into the house, ruining the ceilings or walls.
To solve the problem, you need to understand how the heat leaves the room. If the insulation layer is of good quality, but too thin, it must be reinforced. It is not necessary to re-insulate the entire structure, it is enough to wait for winter and observe in which areas the material or metal base of the roof becomes wet.
If snow falls in your area, carefully examine it. In the place where the heat leaves, it will be soft and will begin to melt. A more complicated method, which does not depend on the season, is to use a thermal imager. This is a special device that will help to establish the exact location, but the services of a specialist or the purchase of the equipment itself are quite expensive.

Poor vapor barrier
If there is condensation in the attic, what should you do first? It is worth checking how well the floors were vaporized. It is quite possible that a gap has formed somewhere. Some construction firms do not do this insulation at all. If the house is old, most likely there is no vapor barrier, since at that time they did not know about it.

To understand that there is no insulation is quite simple: condensation will begin to appear in the living room. He will hit the roof without experiencing obstacles through the ceiling. Warm air will collide with cold roofing material, resulting in moisture in the attic. It should be noted that couples are not uncommon in the house and are formed in large quantities. Therefore, in the absence of a vapor barrier, the attic will quickly become very damp and wet.
It is not difficult to solve the problem: you need to qualitatively isolate the attic space. Most often, a special roll material is used for this, it is affordable and quite easy to assemble on its own.
If the attic is not ventilated
Why condensation collects on the roof is sometimes not immediately clear. The room can be quite well insulated, all materials used are of high quality and of sufficient thickness. The reason may lie in the lack of air movement in the under-roof space.
If the ventilation in the attic is of high quality, then there will be no problems with condensation. This is important not only for heated premises, but also for those that are not used or heated in winter. Excess moisture can appear not only with the inflow, but also with the outflow of air, therefore it is important that there are special holes in the attic for ventilation. Draft in this room will not affect the rooms in any way, but it will provide dryness under the roof.

Lack of ventilation of roofing materials
Condensation on the roof can also appear with an illiterate installation of the roof. Roofing material can be placed on waterproofing, which is a common mistake of inexperienced builders. In this case, condensation will form quickly enough and in large quantities due to the fact that the moisture has nowhere to go: it remains on the roof. Another mistake may be the adhesion of the waterproofing material to the thermal insulation. In this case, the insulation will quickly deteriorate. This is especially true for mineral wool, for which even 5% moisture seriously reduces its performance.

In this case, it will be much more difficult to identify the cause of the appearance of moisture. We'll have to disassemble the roof in order to see what mistakes were made. This will have to be done, otherwise moisture will continue to accumulate and damage the thermal insulation, the replacement of which will be much more expensive than fixing the problem right away. Condensation is especially dangerous for wooden structures.
Violation of technology, substandard materials
The use of cheap materials for waterproofing or a violation of technology can seriously affect the condition of the structure. Condensation may appear as a result of violations of the installation principle or the use of materials whose quality does not correspond to the declared one.
The way to deal with this problem is quite obvious: you will have to replace low-quality products with other materials. If the roof was assembled incorrectly, it will have to be rebuilt.


How to deal with condensation?
It is unpleasant when condensation drips from the roof, so any owner of a building tries to get rid of such a problem as soon as possible. Getting rid of condensation initially allows the use of high-quality building materials, competent installation of the roof and insulation according to the instructions. Otherwise, a variety of problems described above may arise, the fight against which can take a lot of time, effort and money.
Steam is such an interesting substance that it seeps out almost everywhere. Therefore, the vapor barrier must be properly glued with a special tape at the joints of individual sheets and at the junctions to building structures.
If the problem of moisture formation is not acute, you do not need to cover the roof. It is enough to find one or several reasons why condensation can appear, get rid of them, and you will forget about this unpleasant problem forever. What might be required?
- Use of high-quality material for steam and thermal insulation, competent installation of materials. You should not save on insulation: a quality product is always quite expensive, but it guarantees warmth in the house and the absence of moisture and under the roof. Condensation will not form as warm and cold air will not collide. A good layer of thermal insulation should be at least 20 cm.
- Check if the waterproofing membrane is intact. Many builders stretch the waterproofing, causing it to crack. The material should lie free. The film shrinks as the temperature drops, so it can tear if stretched too much. If the insulation is torn, there is no need to replace it entirely. You will need a small patch of the same material with which the hole needs to be overlapped. You can attach the material with construction tape.
- It is important to pay attention to how all the elements of the roof were assembled. That is why you need to follow the installation process, even if professional workers are engaged in it. If you make the roof yourself, stick to the technology strictly.
Conclusion: if condensation has formed on the roof, what to do can be decided based on what caused it. It can and should be eliminated in any case. Do not delay, as a roof overhaul with constant presence of condensate in the attic may be required very soon, and it will cost much more than simple repairs, as a result of which the condensate will leave you.