When doing zero-construction construction, it is very important not to miss any details. Laying waterproofing on a roof is a fairly important procedure, thanks to which the roof can be used for a long period of time and is often estimated to last for decades. This article is intended to help you figure out exactly what is the best way to install waterproofing and what materials are best suited for this.
Almost all rafter systems are constructed from lumber. If we remember the school course, we can say with confidence that wood natural material, which are easily decomposed. Therefore, to increase the service life, developers use special impregnations that do not allow microorganisms to spread in the wood structure, and their name is antiseptics. In addition, there are substances that increase the degree of combustion of the material, they are called fire retardants.
But the most harmful moisture in any wood can be attributed to an excessive amount of moisture. Surely you know that in construction you can use well-dried boards, beams and logs, otherwise during operation they will begin to lose water and, under the influence of gravity, will undergo a process of warping (curvature). Water can wash away all protective impregnations and thereby reduce the wood structure to a defenseless state. This is why most responsible developers spend preventive examination the entire roofing system and if there are deviations, they are promptly eliminated.
Moisture in attic can enter both with air and through condensation from the floors located below. If you didn’t know, then in the process of life human body he gives off quite a large number of moisture, which is immediately distributed in the air and moisturizes it. You are doing this right now by reading these deadlines. When you breathe, a small amount of water gets into the air, much more of it gets when drying things or cooking.
Humid air can enter the room during ventilation. This natural process, from which there is no escape. But not everything is so bad, because you can create ventilation system, which is capable of drawing out humidified air, therefore, the amount of condensation will tend to a minimum. In this case, all lumber will be dry, and their service life will be maximum.
When talking about condensate, do not forget about precipitation that can penetrate into roofing pie, if it is missing waterproofing layer. High-quality products can withstand large temperature changes and prolonged exposure to moisture. Waterproofing soft roof The work is quite simple, but requires serious attention.
Surely you are familiar with a bitumen roll product called roofing felt. It is a heavy roll of bitumen with fiberglass at the base. More recently, the production technology of this material has changed and natural cellulose, which is the main component, was replaced with fiberglass. Thanks to this, the service life of roofing felt has increased several times.
Despite the fact that roofing felt has excellent waterproofing qualities, it can rarely be found as a layer in the roofing pie of a pitched roof. The fact is that in the cold it becomes too fragile and can crack at the slightest deformation. This behavior is unacceptable for high-quality waterproofing. In addition, it is quite easy to damage the roofing felt material and it can tear under strong tension.
IMPORTANT: It is better not to use roofing felt as a waterproofing layer, but as an independent coating on flat roofs it will do just fine.
IN construction field It is difficult to understand the materials due to its large quantity, so sometimes it is useful to read these types of articles in order to stay up to date. Today, it is best to use the following products as waterproofing sheets:
So, now first things first.
This material is the most common raw material for the production of film waterproofing products. Over the past decades, manufacturers have learned to make several varieties of it, and this is what you can find today when studying the construction market:
If we talk about their application, reinforced membranes are much more popular than similar products. Due to their increased strength, they are also used on frames where it is planned to install an impressive thermal insulation layer. Due to its reliability, such a product can be firmly fixed to the rafter legs and there is no fear of damaging it.
Polypropylene was produced after ordinary polyethylene and incorporated it positive traits. After releasing this product, developers immediately noted its improvement in strength and ultraviolet resistance. Private developers decided to use such qualities for good and sometimes cover an unfinished building with it, in this state it can stand for several months until the main construction resumes.
Despite the great benefits of polypropylene material, it still has its disadvantages. Not so long ago, manufacturers produced ordinary material, but it was soon discovered that during operation, condensation does not form outside, but in the thickness of the roofing pie. Of course, this immediately alienated buyers, but this nuance was very quickly eliminated. Today, a special layer of viscose-cellulose substance is applied to polypropylene film, which absorbs excess moisture. The drying process occurs due to natural ventilation, so it's very important to do it right.
When purchasing such materials, the question may arise, which side should the waterproofing be placed on the roof? Today it is quite difficult to make a mistake in this regard. Almost all products sold come with installation and operating instructions. In addition, the side on which the material needs to be laid is often indicated on the canvas itself in order to avoid problematic situations.
Anti-condensation membranes with an absorbent layer must be laid against the insulation so that the “working” side is turned towards it. To ensure high-quality ventilation, it is necessary to leave a gap between the insulation and the waterproofing layer. This material is best suited for laying under metal roofs, where the amount of condensate can exceed the norm several times.
Despite big choice waterproofing materials, quite a lot of developers use glassine. It is a cardboard for roofing, which in turn has been impregnated with refractory bitumen mixed with plasticizers. This product is stored in rolls and used throughout the construction industry where vapor barrier or waterproofing is needed.
The following list will help you figure out which type of glassine is more relevant for you:
IMPORTANT: If you are erecting a temporary structure for domestic needs, then as a hydro insulating material It is best to use cheap glassine, as it is more profitable. If you have the finances, it is best to purchase the P350 brand.
Among all the materials used as waterproofing, this product can be considered the most expensive. If we do not take into account the price tag, we can highlight the great practicality due to which such membranes have become wildly popular.
The perforated membrane can protect roofing system from the influx of precipitation for a long time and at the same time not prevent the condensate from escaping outside. Vapor permeability is achieved through microscopic holes located throughout the canvas. This product is made from synthetic fibers that correct location form a non-woven fabric. The diffusion membrane can be laid on the insulation, thereby eliminating the need to create a counter-lattice.
These membranes are divided into several varieties; they can be single-sided or double-sided. If you purchased the first of them, then you should be careful during installation, because if you choose the wrong side, then moisture will not be able to leave the roofing cake, but will enter it without problems. However, as already mentioned, today it is practically impossible to make a mistake in the design of waterproofing materials, but if you still doubt your abilities, you can turn to specialists for help.
Double-sided membranes are most often installed where there is a need to isolate moisture, but at the same time it is necessary to maintain inflow and outflow clean air. An example is the ridge knot. It always contains a large amount of moisture, but releasing humidified air is not enough, because the drying process will not proceed this way.
Breathable membranes meet every requirement imaginable today. The most important of them are waterproofing and heat conservation; here such a product has no equal. The disadvantage is the high cost.
In addition to the side, films differ in vapor permeability.
Now that you know almost everything about waterproofing materials, you can begin to analyze their installation.
Installation of waterproofing materials is not a complicated process, but some requirements must be met.
The biggest difficulty in laying a vapor barrier layer is that this work has to be carried out at height. Often this causes a lot of unpleasant consequences. Before taking on such work, it is best to repeat the safety precautions for working at height and acquire high-quality safety equipment and special tools.
As a rule, the waterproofing layer is located on top thermal insulation material, which is located between rafter legs. The fastening elements most often are the staples of a construction stapler or small hardware. Most developers save on waterproofing products and believe that this is profitable, but it’s not true. Condensation quickly “eats” the usefulness of the thermal insulation layer and you will need major renovation in just a couple of seasons.
IMPORTANT: If a diffusion membrane was chosen as an insulating product, then the gap between it and the thermal insulation is not created.
To create a good gap you will need small slats. They are laid directly on top of the thermal insulation and covered with waterproofing. It is worth noting that their cross-section should be in the range from 30 to 50 millimeters. If this condition is violated, the roofing pie will not be able to perform its functions correctly.
As a rule, installation of waterproofing film is carried out in horizontal stripes, i.e. across the slope. All work should move from bottom to top, so they say regulations, but there are some nuances here too, namely:
IMPORTANT: Any waterproofing material cannot be laid with strong tension; during operation this will inevitably lead to its rupture. If you don’t want this to happen, then loosen the tension and let it sag between the rafter legs by 1-2 millimeters.
It is worth noting that when installing the ridge element, one should take into account the fact that it cannot be completely covered with waterproofing material. Leave appropriate gaps for the inflow and outflow of air masses. If you still want to completely isolate this area, you can purchase a superdiffusion membrane. It is capable of passing steam in large volumes. In other cases, it is necessary to make a gap of at least 20 centimeters between the waterproofing strips.
Proper waterproofing of a building is one of the most difficult and critical stages of construction or renovation.
If the waterproofing material is laid incorrectly, then within six months the residents of the house will be able to observe an unpleasant picture in the form of:
To avoid the above problems, it is initially important to lay the waterproofing correctly, namely on the side recommended by the manufacturer. Below we will answer the question of which side to lay the waterproofing under different types building materials and in different parts building.
Under the layer of metal tiles, the waterproofing film is laid with the markings up, horizontally from the ridge to the eaves, with an overlap of 15 cm. The film should only be attached to the joists or rafters using a stapler. It is important to remember about the film sag, which must be under the metal tile layer (about 2 cm). It will help air circulate freely and protect the film itself from premature destruction.
Waterproofing floors in rooms such as bathrooms and kitchens requires maximum accuracy in laying a moisture protection layer. IN in this case The waterproofing film is attached with the unmarked side to the insulation.
The roof waterproofing stage begins with laying insulation. Then a waterproofing film is spread over it in an even layer at the joint. The film is laid with the logo facing up, with the adhesive layer directed towards the insulation. Be sure to take into account the ventilation gap for normal air circulation between materials.
To waterproof walls inside the house, the film is mounted with the logo facing up, with the unmarked surface facing the insulation.
Laying the waterproofing film on the walls outside the house is carried out on the insulation, with the markings facing up. The film is secured with a construction stapler with an overlap of 15-20 cm.
Waterproofing films are laid with the unmarked side facing the insulation layer or the ceiling.
Properly laid waterproofing is a guarantee of long service life of the insulation. Keep this in mind and take into account the recommendations of the manufacturer of waterproofing films during repairs and/or construction.
In case of laying roofing material directly on wooden frame, rainwater and condensation from temperature changes is guaranteed to seep through the mounting holes and cracks, which is why supporting structure will always be wet, which will lead to its rotting and destruction. Avoid returning to roofing work After a short time, the roof will be waterproofed.
Why do you need roof waterproofing? Temperature changes lead to the appearance of condensation on inner surface roofing material that flows onto the thermal insulation and wooden structure roof, stimulating its rapid destruction. In this case, wet insulation loses its insulating properties and the ability to perform its functions efficiently.
Previously, the most common material for waterproofing the roof of a house was roofing felt, which is still found today. Considering that the base of the material is paper, its service life is significantly reduced when exposed to moisture. As a result, after 4-5 years of service, the roofing material cracks and allows moisture to pass through, necessitating roof repairs. In addition, the material can tear from a small load, and also has considerable weight, which makes its installation difficult. Typically this material is used simultaneously as a roofing material for sheds or at low pitches.
Insulation with a reinforced film hydrobarrier is modern technology. This is the most inexpensive and easy-to-use material used for pitched roofs for any type of roofing material. A distinction is made between film and membrane, characterized by the presence of microholes. It is the same film, but capable of passing air only in one direction, therefore it is considered new and more modern material. The main advantages are:
Installation of roof waterproofing is carried out according to rafter structures With outside. Rolls of material are rolled out, starting from the bottom of the roof, across the rafters, fixed with a construction stapler. The next layer of insulation is laid with an overlap of about 10-15 cm over the previous one, after which the joint is taped. With such a layout and overlaps, moisture will not be able to seep between the layers of material, but will flow down the roof into drainage system.
When installing roof waterproofing, there is no need to stretch the film; it should be installed with a slight sag between the rafters, which subsequently compensates for the “play” rafter system, and will also prevent it from breaking when the size decreases during the cold season.
It is important to consider that it also matters which side the waterproofing is placed on the roof, because it retains moisture in only one direction. For this reason, the material should be laid on the rafters with the side on which there are no inscriptions or in accordance with the instructions described in the instructions. Otherwise, moisture falling on the waterproofing material will freely reach the insulation.
Waterproofing the roof of a house under metal tiles deserves special attention, since during its operation the humidity and temperature of the under-roof space are of great importance. Insulation film, used for roofs covered with metal tiles, is a reinforcing woven lattice made of polyethylene fiber, covered on both sides with polyethylene film. Thus, the material has strength as well as excellent waterproofing characteristics. It is not cheap, but at the same time it is able to ensure the long-term performance of the roofing functions.
Waterproofing of a metal tile roof is carried out so that Fresh air had the opportunity to move from the eaves to the ridge itself, and then go outside through ventilation holes. Before laying waterproofing on the roof, a gap of 4-5 cm should be created between it and the insulation to ensure ventilation, for which it is necessary to fill the rafters with bars of the appropriate cross-section. The same gap must be provided between the tiles and the waterproofing material, which is also achieved by using bars.
A ventilation gap of 5 cm is required along the ridge, and the lower edge of the waterproofing must reach the gutter so that moisture can easily flow into the drainage system. The only material that is laid directly on the insulation is a superdiffusion membrane.
It is important to understand that right choice and subsequent installation of waterproofing will bring no less benefit than the roofing material, providing the roof and the entire house effective protection and durability.
Waterproofing is a dense layer that is not subject to water penetration. It can be made from paint, roll or other materials whose direct purpose is to protect structures from moisture.
Waterproofing and insulation are carried out in many cases. This can be thermal insulation and protection from groundwater foundation, basement, attics, etc. In all cases where it is necessary to protect a certain space from water ingress and balance the temperature regime.
We will consider which side to lay the waterproofing against the insulation next.
The main purpose of a modern waterproof coating is as follows:
The modern market is saturated with a variety of waterproofing materials. These include membrane films, reinforced mesh, special fabric coverings.
Many people are interested in the question: which side should the waterproofing be laid to the insulation? Often the required direction is indicated on the packaging or on the material itself. There should be no confusion under any circumstances. Since the product is one-sided, if installed incorrectly, it may not perform its intended functions.
There are also coating options, for example bitumen-latex mastics.
Many people confuse these concepts. The main difference lies in the protective properties. Vapor barrier is used to protect insulation materials from exposure to water vapor indoors. The meaning of the second concept is to protect buildings, structures, structures from the outside from the effects of various types of liquids. That is, the insulation is protected from possible precipitation and condensation that forms.
What are “breathable films”?
By non-woven breathable films we mean the ability to pass gas-forming substances such as steam in two directions. In particular, the throughput without using additional elements, such as ventilation gaps, grilles, cuts in the fabric.
Such films release steam from internal space into the insulation, provided that a high-quality waterproof coating allows it to pass out.
Is it possible to leave the isolator open?
The film or membrane contains special polymers. They tend to break down when exposed to sun rays. Therefore, some manufacturers provide an additional layer with UF protection. However, this does not guarantee 100% protection. The service life of the insulating material, during which it retains its performance characteristics, is limited. The average duration is three to four months.
Which side should the waterproofing be laid towards the insulation?
It should be applied following the instructions provided by the manufacturer. Often such instructions are attached separately or marked on the product itself. If an unexpected situation arises and the instructions are missing or lost, there are several basic rules.
The basic rule is that the coating is laid on outer surface thermal insulation. Thus, the latter is protected from the adverse effects of the environment.
The best way to secure the insulator is with a counter-lattice. It must be installed correctly. Has two sides:
The sheets must be laid overlapping each other, approximately 5-10 cm. This is necessary so that water does not find a loophole and spoil the heat-insulating building material.
Some tips about the installation process:
A water-protective layer is sometimes used in indoors. For example, to enhance the waterproofing properties of insulated pipes.
Which side should the waterproofing be laid to the insulation - face down or inside out? A question that interests many. First of all, you need to decide on the type of product to use. Lubricants naturally they don’t have sides, they are simply applied.
Roll materials, as a rule, have one rough side. She needs to be laid in the inward direction.
A few rules to help you navigate:
It should be remembered that the question “which side to lay the waterproofing against the insulation” can be answered by specialists, masters of their craft.
Before purchasing, be sure to consult and find out all your questions on the spot.
As a rule, the required side is indicated by the manufacturer, and it is problematic to mix it up.
