Technology for installing PVC membrane roofing. Membrane roofing. Synthetic ethylene-propylene-diene rubbers epdm and skept
One of the latest innovations on the market of modern roofing materials is membrane roofing. The technology of its installation allows for the installation of the roof covering without seams, which gives the roof the best waterproofing characteristics. The market offers various membranes that differ in composition and installation methods.
Among this variety, it is possible to choose an option to cover any type of roof. Let's look at what a membrane roof is and get acquainted with the technology of its installation on various surfaces.
In this article
Types of membrane roofing
The production of membrane coating is based on polymers and artificial rubbers, which give this type of roofing its elasticity. There are three types of this material.
Based on polyvinyl chloride
PVC membranes are based on polyvinyl chloride, which is the basis of many insulating roofing materials. Elasticity of such a coating is given by a volatile plasticizer, and flexibility is provided by a reinforcing mesh made of polyesters. Such characteristics make it possible to use PVC membranes on roofs of complex structures.
The method of laying this membrane eliminates the presence of seams, which greatly increases its resistance to leaks. In addition, these membranes are available in various colors, including light ones, which allows the roof to reflect the sun's rays and not heat up in hot weather. Installed using heat welding.
This type of membrane roofing, despite its advantages, has an acceptable cost, which makes it a popular material for roofing.
EPDM membrane based on artificial rubber with reinforcement
EPDM membrane based on artificial rubber with reinforcement using a polymer mesh. For improvement strength characteristics essential additives are added to it. The waterproofing properties of the EPDM membrane are high due to its high adhesion to bituminous surfaces. Mounted using adhesive method.
The disadvantage of the roof is its high cost, which pays off long term service - more than half a century.
The TPO membrane is a new product in the domestic roofing market. The material is produced on the basis different types rubber, to which various stabilizing additives are added to increase strength, elasticity and fire resistance. This thermoplastic material is based on various types of polyvinyl chloride, rather than rubber. Installed by heat welding.
Scope of application
Membrane roofing is usually installed on flat or low-slope roofs. The convenience of this type of roofing materials is the fact that they can be laid on the old roofing without dismantling it, which significantly saves time and money on improving the roof or repairing it. 
When using membranes on flat roofs ah, you can create an exploitable surface on which you can place various objects, including those with high traffic. This is convenient when creating a roof over underground garage or parking, when arranging a cafe on the roof of an office or shopping center.
Membrane roofing is actively used in the areas of multi-storey and industrial construction, while their use in the sector of private houses is only gaining momentum.
An important advantage of using membrane materials is the absence of additional waterproofing in the roofing pie.
Key points when choosing and working with membrane coatings
There is an opinion that membrane roofing materials are only suitable for flat concrete roofs. Let’s refute this opinion: membranes can be installed on any type of roof and are especially convenient for repairing old roof structures.
Calculation of the use of membrane roofing should be based on the following rules:
- It is necessary to take into account the load on the rafter system or walls of the building. If they are reliable, then there is the possibility of ballasting the membrane. If there is no confidence in the strength of the house, then it is better to choose a welding or adhesive method of fixing membranes;
- When calculating the amount of material required to cover the roof, it is necessary to take into account overlaps of 5 cm, as well as the need to install a membrane on all types of junctions.
The main advantage of a membrane roof - the absence of seams - can be destroyed overnight by incorrect installation technology. Take the time to check the tightness of the seams: after they have cooled, run a screwdriver along the seam and make sure there are no holes.
Installation
The technology of membrane roofing depends on the type of coating chosen and the base for the roof. Let's look at the basic installation methods.
Glue method
This method is used to install the EPDM membrane. For this, special double-sided adhesive tapes are used to seal the joints of the membrane material. This installation technology is convenient in private construction, as it does not require the use of specialized equipment. Gluing the canvases is done quickly enough and does not require special preparation. 
However, this method does not provide a durable sealed coating. At the joints, the adhesive tape begins to come off over time and allow moisture to pass under the roof.
Heat sealing method
Welding membrane joints is done using heated air. PVC and TPO membranes are laid using this method. A welding machine is used that supplies a stream of air at a temperature of 600°. A construction hair dryer with the ability to heat the air to at least 550° can be used.
The membrane sheets are laid overlapping each other, the edges are heated with a burner and glued together. After the material has cooled, a single web is formed with tightly sealed seams. After using the burner, the seams are completely sealed and have the same elasticity as the rest of the fabric.
Laying rules
The technology for laying PVC membranes contains a number of rules:
- Before sealing the seams, it is important to clean the surface of the membrane from any contaminants, including grease and chemicals;
- The canvases are laid freely, without tension. The amount of overlap between two adjacent canvases must be at least 5 cm;
- It is important to carry out the welding quickly enough, without staying in one place for a long time and without underestimating the recommended temperature values. With a very thick seam, there is a high probability of the fabric tearing in the area near the seam;
- When the temperature is too high welding machine the membrane will burn and not stick together;
- The optimal seam width is at least 2 cm. If it is smaller, it is necessary to install a round membrane patch on top of the seam.
Using construction hair dryer It is necessary to follow the nozzle, which heats the joint of the sheets, with a roller. When using a welding machine, this is not required, since the machine independently rolls the surface to be welded.
Ballast method
Unlike welding, the method of fastening the membrane with ballast does not require the use of special equipment, which makes it acceptable for do-it-yourself installation. The ballast method is possible on flat roofs and roofs with a slope of up to 15°.
This technology requires the presence of strong load-bearing structures, since fixing the PVC membrane with ballast is associated with a lot of weight.
Installation is as follows:
- Roll out membrane rolls on the base;
- Fastening the material around the perimeter and at junctions with adhesive tape;
- Loading on top of the ballast membrane: not less than 50 kg per 1 sq. m.
Crushed stone, pebbles, concrete blocks or paving slabs are suitable for ballast. It is important to consider that if the ballast has sharp corners which can damage the surface of the membrane, it is necessary to first cover the roofing with non-woven material. 
Ballast fastening of PVC membranes is convenient due to the possibility of arranging a used roof.
Installation of membrane covering on corrugated sheets
The option of laying a membrane on roofs made of corrugated sheets is quite common, thanks to which the roof made of corrugated sheets is insulated and soundproofed.
Installation in this case follows this algorithm:
- A vapor barrier is laid on the corrugated sheets with overlapping sheets;
- Insulation boards are laid in two layers on top of the vapor barrier. It is important to observe overlap top layer joints of the lower;
- The insulation is attached to the base using self-tapping screws;
- A membrane covering is laid on the insulation, the seams of which are sealed with special equipment;
- At the junctions, membrane overlays are made.
Construction technologies and trends in roofing are constantly changing, barely keeping pace with the emergence of new materials and production methods. It is not surprising that those roof coverings that were considered practical and reliable just a few decades ago are now fading into the background, giving way to more technologically advanced, durable solutions. Thus, membrane roofing has practically replaced the old-style rolled materials used to cover flat or low-slope slopes, due to its strength, elasticity, and tightness. In this article we will talk in detail about the characteristics of PVC, TPO and EPDM membranes, as well as the technology for their installation.
Membrane roofing – modern way installation of flat and low-slope roofs using modern polymer roofing materials, the multilayer structure of which qualitatively distinguishes them from roll coverings last generation (roofing felt, roofing felt, glassine).
- Mechanical strength. The use of more elastic polymers makes membrane materials more resistant to mechanical damage, resulting in increased service life of the coating.
- Elasticity. Roofing membranes are much more elastic than rolled cardboard-based roofing materials, so they make it easier to install the coating on the structure complex shape.
- Tightness. The technology of laying membrane roofing allows you to obtain an almost monolithic, hermetic finishing layer without heating.
- A light weight. Low weight and small thickness of the membrane allows for repairs old roof without dismantling the structure.
- Convenient installation technology. Roofing membranes made of PVC, EPDM or TPO can be installed at any time of the year without the use of heating equipment. Moreover, installation can occur on any type of base.
Note! The obvious advantage of a roofing membrane is the ability to cover large areas of roofs in a short time without reference to weather conditions or ambient temperature.
Types of membranes
The appearance of roofing membranes is associated with the development of the chemical industry and the desire of construction technologists to introduce the excellent qualities of synthetic rubber into waterproofing coatings. The technology for the production of membrane sheets from PVC, TPO, EPDM allows us to obtain a sealed finishing layer of the roof with a minimum number of joints.
- Since the properties of the membrane are mainly determined by the polymer on the basis of which it is made, they are divided into the following groups: PVC membranes. These roof coverings are made from a durable, flexible, temperature-resistant polymer known as polyvinyl chloride. PVC-based material is cheaper than analogues based on other compounds. PVC membrane roofing, unlike analogues, has a light color, due to which it reflects more than 20% sun rays
- and heats up less.
- EPDM membranes. This group of membrane sheets is made from ethylene propylene diene monomer, which is more often referred to as “synthetic rubber”. They are more expensive than PVC-based materials, but thanks to the reinforcement and elasticity of the polymer, they last more than 50 years.
Please note that membrane roofing has a multi-layer structure, each layer of which gives the material a certain property. The working layer of the membrane is responsible for the elasticity and tightness of the coating, and the protective layer is responsible for the strength properties and resistance to ultraviolet radiation.
Mounting methods
Due to the composition and form of release, installation of membrane roofing on roof structures with a slope of 0 degrees is allowed. Experienced craftsmen note that this option is optimal for a flat, flat, exploitable and low-slope roof. The thickness and weight of the membrane fabric is 1.5-2 times less than that of traditional rolled materials, so their installation takes less time and effort.
- The technology for fixing the coating depends on the type of membrane, type of base and roof structure. The following methods of fastening the canvases are used:
- Ballast mounting. This method consists of using ballast material (pebbles, expanded clay), which is scattered on top of a membrane laid on the base of the roof, to fix the sheet on the slope.
- Adhesive fixation. The membrane roof can be fixed using a special adhesive. The polymer sheet is glued to the base of the roof without making mounting holes, due to which the tightness of the roof is not compromised. Fastening by thermowelding method. Another way to fix a membrane roof is to glue the sheet using heating equipment. Under influence high temperature
- , the polymer roofing material is soldered together, forming a monolithic, almost seamless coating.
Mechanical fixation. A less common method of fixing a membrane roof is fastening with fasteners (nails, screws, staples). The use of this method is undesirable, since it involves the production of a large number of mounting holes that violate the tightness of the roof.
Important! Experienced roofers recommend installing membrane roofing using a heat-welded or adhesive method. However. It is worth remembering that the result of fixation depends on the quality of preparation of the roof base surface for work. To improve adhesion between materials, you need to clean the base from dust, dirt and grease. Roofing materials based on bitumen have a number of disadvantages that reduce their service life and limit their scope of application. This prompted developers to create a new generation of rolled waterproofing materials -.
polymer membranes
Roofs with membrane coating are structurally practically no different from other types of soft roofing, only instead of roofing felt or rubemast, material made of petroleum polymer resins or synthetic rubber is laid on top. There are three options roofing pie under such coverings.
Traditional soft roof with concrete base
Traditional roofing is constructed on unused roofs from hollow or ribbed reinforced concrete slabs. In this case, the following sequence of layers is maintained (from bottom to top):
Inversion roofing
An inverted roof is a concrete roof in use, in which the traditional order of layers is slightly changed: the membrane is located under the insulation. On such a roof there can be a cafe, a parking lot or a lawn. The order of layers here is as follows:
Pitched roof with rafter system
Pitched design rafter roof looks like this (from bottom to top):
Advantages of roofing membranes and their types
Roofing polymer membranes are superior to rolled bitumen-polymer materials (BPM) in all characteristics.
The only drawback in comparison with BPM is the high cost. But over many years of operation, the cost of maintaining a membrane coating due to the durability of the latter turns out to be half as much as compared to BPM.
Roofing membranes are made from:
Synthetic ethylene-propylene-diene rubbers EPDM and EPDM
The first roofing membranes were rubber and, despite the emergence of more advanced varieties, they are still produced to this day. This is explained by their following advantages:
- low cost;
- no need to use special equipment during installation;
- resistance to solvents, oils and bitumen.
Panels of EPDM and EPDM membranes are held together with a special glue - this is their only, but quite significant drawback. The membrane itself correct installation and operation, according to calculations, it can last up to fifty years (proven service life is 40 years), but the seams come apart much earlier. They have to be re-glued periodically, and if this is not done in a timely manner, the coating will leak.
In Russia, rubber (SKEPT) membranes “Cromel” and “Rukril” are produced. They are not inferior in quality to foreign analogues, for example, from Carlisle Syntes Systems and Firestone (USA), but they are half the price.
EPDM and EPDM membranes are produced in three versions:
- soft;
- rigid (reinforced with synthetic mesh);
- with reflective coating (for hot climates).
Polyvinyl chloride (PVC)
PVC membranes are more expensive than rubber ones, but have an important advantage: polyvinyl chloride is a thermoplastic, that is, after heating to a state of softening and removing the thermal load, its physicochemical properties do not change, therefore individual panels can be joined by heat welding (heating with hot air) into a solid coating . The seams in such a membrane do not come apart and do not leak, even if the coating is constantly under water.
In terms of durability, PVC membranes are practically not inferior to rubber ones: the proven service life is 35 years.
Flaws:
- are not resistant to oils, solvents and bitumen, which requires taking appropriate safety measures during transportation and storage;
- Installation requires special equipment.
It is precisely the need to use special tools for PVC welding does not allow this type of membrane to completely replace rubber products, which are still in demand.
Thermoplastic olefin elastomers (TPO)
The material, like PVC, is joined by heat welding. Unlike polyvinyl chloride, it does not emit harmful volatile substances, but is much inferior to other membranes in plasticity.
Connecting TPO-membrane sheets requires the use of special equipment Membrane roofing: installation technology
During installation, the rolls are simply unrolled on the roof. Leveling the base is not required - unevenness does not harm the elastic membrane. There is also no need to remove the old roofing - you just need to cover its sharp elements with two layers of geotextile.
- panels are glued or welded;
- fix the membrane on the roof.
Let's look at them in more detail.
Adhesive connection of sheets
Membranes made of synthetic rubber (EPDM and EPDM) are glued together. The procedure is as follows.
- The panels to be joined are laid with an overlap of 150 mm.
- On the lower panel, make several marks with a marker along the entire edge of the upper one, indicating the width of the overlap.
Along the edge of the top panel, use chalk or a marker to mark the boundaries of glue application - On the top panel, at a distance of 300 mm from the edge, a series of glue strokes are applied to temporarily fix the folded edge.
Glue strips are needed to temporarily fix the edge of the top panel - The edge of the top panel is folded back and pressed against the previously applied glue stains.
The edge of the upper strip of the membrane is bent outward along its entire length and lightly pressed in places where adhesive tracks are applied - Both panels in the overlap area are coated with glue. When applying the composition to the bottom panel, they are guided by the marks made with a marker.
Using a special brush, an adhesive composition is applied to the lower and upper membrane panels along the entire length of the seam - A special tape with a glossy-smooth surface is placed on the area of the bottom panel greased with glue so that its edge protrudes beyond the marker marks.
An auxiliary tape is placed on the glue-smeared edge of the lower membrane - The bent edge of the top panel is peeled off and returned to its normal position, placing it on tape, which prevents the panels from sticking together, allows them to be smoothed out and a complete fit is achieved.
The bent edge of the top panel is returned to its place - Holding the edge sticking out from under the top panel, the tape is gradually pulled out and immediately rolled over the overlap with a roller, pressing the panels together.
The auxiliary tape is gradually pulled out from under the membrane, and the edge of the upper panel is carefully pressed against the lower one, smoothing the seam with a brush
Gluing panels should not be done in windy weather: debris will get into the joints and the seam will turn out to be of poor quality.
Video: technology for gluing EPDM membranes
Heat welded connection of sheets
Hot air welding is used to join PVC and TPO membranes. The quality of the seam depends on a number of parameters:
- heating temperatures;
- the width of the welding machine nozzle, that is, the width of the seam;
- welding speed;
- pressure forces on the welded edges.
Heating temperature is the most important parameter. Both underheating and overheating are dangerous. In the first case, the edges of the panels will stick, but will not fuse into a monolithic seam, and such a connection will separate at the slightest load. In the second, a so-called temperature shock will occur: the polymer molecules will break up into small compounds and the material will lose strength. The difficulty is that the optimal heating temperature depends on the ambient temperature and, to some extent, on its relative humidity.
Welding of panels is carried out using a construction hair dryer equipped with nozzles 20 and 40 mm wide For example, at an air temperature of +25 o C, normal humidity (40–60%) and a nozzle width of 40 mm optimal temperature heating is 560 o C.
To accurately select all parameters in accordance with current weather conditions, test welding is carried out before installation. They connect two small fragments of the membrane and then try to tear them apart along the seam. Based on the test results, the following conclusions are drawn:
- the rupture occurred outside the seam - the welding parameters were selected correctly;
- rupture along the seam - the material is overheated;
- the panels in the seam area peeled off from each other - the temperature turned out to be low.
Test welding is performed each time after:
- long shutdowns of the device, during which it has time to cool down;
- significant changes in weather conditions.
Having established the optimal parameters, proceed with installation.
Video: hot air welding of PVC membrane
Junction nodes
Adjacent to vertical structures- walls, parapets, ventilation pipes- formatted as follows.
Video: installation of external and internal corners of a PVC membrane roof
Features of making T-shaped seams
Often a long panel has to be assembled from two or more pieces. In this case, the transverse seams are welded first, and then the longitudinal ones. The result is a T-shaped seam.
It is not recommended to place transverse seams on the same straight line: they should be offset from each other Transverse seams are arranged staggered - with a shift. The intersection of four layers of material at one point is not allowed. The corners of the panels are rounded for a smooth transition from one panel to another.
The easiest way is to press down the membrane with a layer of crushed stone or gravel weighing 50 kg/m2. This method is possible under the following conditions:
- the roof slope does not exceed 15 o;
- the roof is capable of bearing the specified load (in addition to snow).
Large stones are used so that they are not blown away by the wind. If their corners and edges are sharp, geotextiles are first laid over the membrane.
In a ballasted roofing system, the membrane is laid loosely and covered with geotextile to protect it from damage. Instead of stones, you can lay paving slabs or concrete blocks on the surface.
Mechanical fastening method
If it is not possible to use ballast, the membrane is fixed with special fasteners.
- Bolts, anchors or self-tapping screws (depending on the type of base) with large plastic caps. Such caps are not capable of pushing through the material.
- For slopes over 10 o - with the specified hardware in combination with disk holders.
- On protruding roof elements - with special edge slats with a seal.
Only reinforced membranes can be fastened mechanically.
For fastening membranes, special fasteners are produced, the design of which eliminates damage roofing material Fasteners are installed along the seams in increments of 200 mm. If the slope is more than 2 o, it is installed in the valleys extra row fastening elements.
Adhesive fastening of the membrane
Glue method expensive and least reliable, therefore it is used last, when other methods are excluded.
You can resort to continuous gluing of the membrane, but more often the glue is applied selectively:
- along the perimeter;
- along the seams;
- on the ribs;
- in the valleys;
- in places adjacent to vertical structures and pipes.
Equipment for installation of membrane roofing
The only specialized tool for laying roofing membranes is a welding machine. It is used only when installing thermoplastic membranes - PVC and TPO. Welding is carried out without filler material.
Membrane welding machines are divided into three types:
- automatic;
- semi-automatic;
- manual.
Automatic devices
Automatic welding machines are large, heavy machines designed to weld straight, long seams on a core, easily accessible part of a horizontal or vertical surface. Here are their advantages:
- accurately maintain temperature, welding speed and pressure on the surfaces being joined that are optimal for current weather conditions, which ensures high quality seam;
- provide optimal air flow (relevant for TPO membranes);
- long sections are welded with consistently high quality, whereas when manually welding such seams, due to monotonous work, the human factor is especially pronounced and, as a result, the quality suffers greatly;
- do not require high qualifications from the operator - he only adjusts the parameters and corrects the direction of movement of the machine along the seam.
In addition to quality, the automatic device provides high installation speed - 2–8 meters per minute (m/min). With the manual method, the welding speed is no more than 0.4 m/min.
The automatic welding machine ensures high installation speed and stable quality of the weld seam Semi-automatic devices
Semi-automatic devices are used in places where it is impossible to use a massive machine: on roofs with large slope, vertical surfaces, parapets and other structures. They also provide high speed and good quality assembly seam, but are much inferior in these parameters automatic devices.
Semi-automatic installations are used when performing work on vertical sections, parapets and roofs with a large slope Manual hot air guns
Manual devices are used in complex and hard to reach places abutment of the roof covering to various designs, on curved sections, when welding short end seams. A manual welding machine is called a hot air gun. It is lightweight and easy to use; in emergency situations it automatically turns off. Operating mode parameters are shown on the display. The air temperature is stepwise regulated by a 10-position switch in 60-degree increments. The most advanced models maintain the required temperature automatically.
Hair dryers are designed for welding membranes in hard-to-reach places and for installing membrane roofs of small areas Leading manufacturers of equipment for welding membrane roofs
Equipment for welding TPO and PVC membranes is produced by companies in Switzerland, the USA, Germany, and Sweden.
Leester Process Technologies (Switzerland)
The following models received the highest ratings from users:
Forsthoff Gmbh (Germany)
Forsthoff GmbH is constantly improving its products. Thus, in the manual welding machines of the “S” series, released in 2009 (Grand-S Electronic, Hot Air S, Quick-S Electronic, etc.), the following solutions were used:
Herz (Germany)
In addition to hot air guns, the catalog of this manufacturer includes testers for checking the quality of welds and much other equipment. The Laron automatic welding machine and the manual Rion welding machine are in greatest demand, while models of the Eron, Mion and Comon series are used quite rarely when installing roofing membranes.
High performance(up to 7 m/min) of the Laron machine allows you to significantly reduce execution time installation work Lansite (USA)
The company produces high-quality hand-held devices in the budget segment. The assortment is represented by two series - Tornado and Hurricane.
Sievert(Sweden)
Creator of reliable automatic welding machine SievertTW 5000, popular among professionals. The Penoplex St. Petersburg company even officially recommends using it when installing its Plastfoil membranes. Features of the device:
- propulsion system with all-wheel drive(the quality of the weld increases regardless of the thickness of the membrane);
- adjustable front wheels allow you to weld at different angles;
- A powerful engine allows you to climb slopes with a slope of up to 30 o.
Video: machines and accessories for welding PVC membranes
Polymer waterproofing membranes are an almost ideal roofing material: they are durable, elastic, and resistant to all negative atmospheric factors. But the coating will live up to expectations only if it is installed correctly, so it is advisable to trust it to certified specialists.
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In construction, new methods are increasingly appearing that simplify the installation of roof structures. Thus, the installation of a membrane roof is a technology that has a number of advantages over traditional methods, mainly due to the production of a monolithic roofing covering with impeccable waterproofing qualities.
The installation of such a roof is carried out from special membrane materials, the range of which is constantly expanding on the market, so finding them is quite easy.
Characteristics of materials for laying membrane roofs
Roofing membranes are conventionally divided into several groups, each with its own characteristics, advantages and disadvantages. Let's highlight the most common of them:
Experienced developers install membrane roofing using any materials, choosing for each of them suitable technology. Below is suggested detailed description some of them.
Efficiency of ballast fastening of membrane roofs
The simplest fastening of membranes is considered to be ballast, which is suitable for roofs with a slope of up to 15 degrees.
The work is carried out as follows:
Features of mechanical fastening of membranes
In case of insufficient fastening load-bearing structure roofs for laying membranes using the ballast method membrane pvc can be equipped by mechanical means. Also, such fastening is important when gluing the membrane is difficult. waterproofing material to the roof structure.
In the case of mechanical fastening, reinforced concrete is taken as the basis, wooden surface, corrugated sheet. To lay the membrane, additional slats are mounted on each edge of the protruding elements, as well as along their entire perimeter, onto which a sealing layer is applied from below (more details: " ").
The roof is attached membrane type telescopic fasteners, presented in the form of a plastic umbrella with a hat and a metal anchor. If the roof slope exceeds 10 degrees, you will need optional equipment for membrane roofing, in particular, disk holders.
The use of mechanical fasteners is necessary where they overlap each other (in areas of overlap). Fastening elements are located at intervals of no more than 200 mm. When the roof slope is more than 2-4 degrees, additional material is fastened next to the valleys.
Description of the technology for gluing roofing membranes
It should be noted that it does not matter what material will be used in the work, the main thing is that it turns out durable roof- PVC membrane is glued to the base quite rarely, since this method is relatively uneconomical and does not provide strong fastening of the material to the base. However, there is still a demand for adhesive joints, especially if none of the previously listed methods are suitable. It is performed using special adhesive mixtures.
Also waterproofing membrane for roofing it can be glued not over the entire surface, but in places where the material is pressed against the base, as well as at the connections of the sheets to each other and to other problem areas, which are considered to be ribs, valleys, adjacent to buildings, chimneys, ventilation ducts.
Use of heat-welded roofing systems
Connects soft roof the membrane, like most other roofing structures, is heat-welded using a special welding machine that directs an air stream of about 400-600 degrees. The weld seam can be from 20 to 100 mm wide - no more.
Membrane roofing has excellent waterproofing characteristics. The material can be mounted both on a prepared roof base and on an old roof covering during roof repair.
Scope of application and types of material
Installation of membrane roofing is primarily in demand when arranging flat roofs and roofs with a slight angle of slope. The ability to install the membrane without dismantling the roof covering, which has lost its reliability, significantly simplifies and reduces the cost of roof repair.
The use of membrane materials on flat roofs allows you to create a serviceable roof. The advantages of this type of coating, primarily laid using the heat-welded method, include high waterproofing properties, due to which additional waterproofing of the roofing pie is not required. The membrane can be made from various materials - PVC, EPDM, TPO membranes.
When choosing a material, you should pay attention to the technology of laying the sheets: PVC and TPO membranes are installed using hot air welding, EPDM membranes are installed using the adhesive method.
The heat-welding method requires the use of specialized equipment and certain skills in working with it. Installation using adhesives or double-sided adhesive tapes, or using mechanical fasteners, can be done on your own.
Installation of membrane covering
The material is laid in one layer, thanks to which the installation of the roofing is carried out quite quickly. The membrane has a thickness of 0.8 to 2 mm, 1 square meter of material weighs on average about 1.3 kg. Compared to installing a bitumen-polymer coating, laying a roof made of membrane material takes half as much time.
Durable, puncture resistant, resistant to temperature changes and ultraviolet radiation. The membrane can be laid on any type of base. Depending on the roof configuration, the presence of parapets, drains and other elements, the installation technology is selected. It could be:
- ballast mounting;
- adhesive connection;
- heat welded connection;
- mechanical fastening.
The membrane material sheets are connected to each other using adhesive tape or by welding.
Adhesive connection of sheets
To make a one-piece membrane coating from strips of rolled material, you can use special double-sided adhesive tapes. The advantage of this installation method is a simple and accessible technology that does not require the use of special equipment. But it should be noted that the adhesive connection of seams is not characterized by high reliability and durability, unlike the welded method.
The adhesive is susceptible to deterioration, and over time, such a roof may require repairs at the joints.
Joining the sheets using glue requires the installation of a membrane roof made of a material based on synthetic rubber. IN Lately a number of manufacturers have begun producing EPDM membranes designed for hot air welding, but their cost is significantly higher than that of traditional materials of this type.
Heat welded connection of sheets
Membrane roofing, the installation technology of which requires the use of special welding equipment, is made of PVC and TPO membranes. This method involves welding sheets of roofing material overlapping with hot air. Joints made by welding can withstand more than high load tensile strength than the canvas itself, and are characterized by absolute tightness.
Welding machines maintain an optimal level of heating of the material by supplying a stream of air heated to 400-600 degrees. The width of the weld can be from 20 to 100 mm. For welding sheets on large areas Special automatic equipment for membrane roofing is used. Devices equipped with wheels move smoothly along the seam, high-quality welding of which is carried out automatically. Welding speed, temperature and other parameters are controlled electronically.
For installation in hard-to-reach places, arrangement of junctions, curved sections, complex assemblies, the use of manual welding machines and special rollers for rolling material heated to a plastic state is required.
To ensure high welding quality it is required:
- monitor the cleanliness of the surface of the material being welded (dust, dirt and traces of various substances must be removed before installation);
- lay the membrane without tension;
- create an overlap with a width of 50 mm (to ensure a weld with a width of at least 20 mm);
- After installation, it is necessary to check the quality of each seam.
If a defect is detected in the weld or damage to the membrane, a patch of the same material should be installed. The installation technology requires welding a piece of fabric with rounded edges, which is at least 50 mm in length and width greater than the size of the damage.
To select the optimal operating mode for the welding machine in current weather conditions, it is recommended to perform test welding first.
Step-by-step instructions for installing a membrane roof can be obtained by watching the video.
Ballast fastening of membranes to the base
Laying membrane roofing using the ballast method can be used in cases where the roof slope does not exceed 15 degrees. This technology is economical and is used when installing flat roofs. Work progress:
- the base is thoroughly cleaned of debris;
- the canvas is laid on the base and secured by welding or glue around the perimeter, as well as in places where the base interfaces with vertical structures;
- to press the canvas to the base, ballast is laid at a rate of at least 50 kg per 1 sq.m.;
- bulk ballast must be carefully leveled.
The material for ballast can be:
- gravel, crushed stone (20-40 mm);
- large pebbles;
- concrete blocks;
- paving slabs;
- any massive objects.
Before laying ballast that can damage the membrane (broken stone, untreated gravel), you should lay non-woven fabric or lay down mats. Application paving slabs as ballast, it allows you to equip a reliable and aesthetically pleasing flat roof.
This method of fastening the covering can only be used on roofs designed for a high total load.
Adhesive and mechanical fastening of membranes to the base
The membrane sheet is attached to the base using an adhesive composition when laid on a roof of complex shape. In addition, this installation option is practiced when installing roofs that experience high wind loads. Application mounting adhesive allows you to install a membrane roof on a base made of reinforced concrete, profiled sheets, or wood. The canvases are welded or glued together. To strengthen the coating on protruding elements and roof edges, special edge strips equipped with a sealing layer are used.
