A traditional flat roof must be covered with a waterproof, wear-resistant material. The usual coating for a flat roof is two layers of rolled material containing a large amount of bitumen with polymer additives. It is the presence of polymers in bitumen that gives the coating the necessary elasticity and temperature resistance. Bitumen-polymer roll coating for flat roofs is the cheapest today. Provided installation technologies are followed, its service life is not short - 25 years or more. Let's look at the main design features of a roof with a bitumen coating and how the simplest and cheapest flat roof is created.
Flat roof construction with bitumen coating
As you can see, the waterproofing bitumen-polymer coating only crowns the big pie. In a flat roof, everything must be done correctly, otherwise the coating will not perform its functions or the completion time will not be long at all.
Preparation of the base for the application of bitumen roll materials
When preparing the base for laying rolled bitumen materials, it is important to properly prepare the junction of the roof with a continuous parapet (vertical structure), which must be plastered to a height of material installation - at least 300 mm. 
A fillet is made along the perimeter of the roof near the parapet - a special collar with an inclination angle of 45 degrees, height and width - 100 mm. It ensures smooth bending of the coating when transitioning from horizontal to vertical. It can be made of cement-sand mortar or dense insulation.
Substrates made of concrete or cement-sand mixture must be dry and clean before laying bitumen roll materials. Humidity no more than 4%. Debris and dust are collected on the surface, then the surface is primed with a bitumen primer, including the fillet and parapet to the height of the installation of the material.
How should layers of bitumen coating on a flat roof be laid?
Bitumen roll materials are laid on the roof in two layers in strips. The material is heated by an open flame from a burner. Warming up is carried out while unwinding the roll over the surface so that the bitumen begins to flow and fuse onto the base. 
All strips of the first layer are laid with a mutual overlap in width by 8 cm, and end-to-end in length by 160 mm. In this case, you need to make sure that the joints in adjacent strips do not form one line - they move at least half a meter. 
The second layer of roll bitumen-polymer coating is laid along the joints of the strips of the lower layer - the solid material of the second layer must cover the joints completely, the distance from the joint to the edge of the strip of the second layer is at least 0.3 meters.
The process of laying bitumen roll material
A strip of material is rolled out over the surface to test its position. The material is then wound onto a cardboard spool, which is inserted into the holder. The material is heated with a gas burner while it is uniformly rolled out. It is important to heat the material so that a bead of flowing bitumen constantly forms under them, and also along the edge of the strip the bitumen flows out to a distance of 20 -25 mm. The previously laid strip at the joint also warms up.
In places adjacent to vertical structures, laying is carried out to the height of the fillet. And if the roll unwinds along it, then an additional strip of material is placed on the fillet.
Joining of rolled materials with vertical surfaces
The adjoining is carried out in separate pieces of material, and they must lie on the horizontal part for at least 150 mm of the first layer and 250 mm of the second layer (100 mm overlaps).
The first layer should extend onto the vertical parapet by at least 250 mm, and the second layer with the topping should extend at least 300 mm, but preferably up to half a meter (50 mm overlaps).
The material of the required length is cut, for the first layer it is 250 mm vertical + 150 mm horizontal + fillet length, placed in its place, then it is heated and its upper part is glued, then the lower. The second layer is cut and glued in the same way when laying the second layer on the roof.
How bitumen roll materials are joined to vertical surfaces
The junction points of a flat roof covering with any other structures are the most critical nodes. They must be arranged according to the rules most carefully. The edge of the covering on a vertical structure is protected from water using various methods. 
On simple roofs, such a covering can be done with your own hands. For example, with such material, using elements of the technology specified here, it is possible to cover flat roofs of garages, sheds, etc. But for high-quality coating of houses with bituminous materials with installed drainage funnels, it is better to invite specialists.
My flat roof. Errors. I will redo it (photo)
I decided to build a flat roof over the garage attached to the house. So that you can sit there in the summer, drink tea, and so on.
The garage was covered with hollow-core slabs, 4.5 meters in length. This is how it was at the very beginning, before installing a flat roof. October 2016.
The slabs have no slope; I intended to use it as insulation.
It turns out later that the “lack of slope” among builders actually means something completely different. I aimed with a laser level and it turned out that the part of the roof behind me (in the first photo) has a level about 10 cm lower than the opposite part of the roof. The slabs themselves have a convexity in the middle, and the level of the side near the wall is lower than the level in the middle of the slab.
My first thought was to fill the roof (by hand!) with cement screed to bring its level to the horizon. I was very naive, yes) Next, I planned to lay wedge-shaped insulation XPS-Wedge on top of the screed to set a slope of 1.7% and at the same time insulate the roof so that there would be no condensation on the ceiling from ice slabs. In part of the garage I have a heated boiler room, so the roof needs to be insulated.
I intended to use the board visible in the photo as formwork to pour cement screed in strips 1.5 meters wide.
I started from the far end of the roof. In the photo ^ you can see how I made this formwork and set the horizon level with aluminum corners - one screwed to the parapet, the other to the board. As a rule, I planned to guide along these corners so that the screed would be even. The next stripe of filling would be made relative to the level of the previous stripe, so that the level would be normal, to the horizon.
I started lifting cement onto the roof with buckets, and only then realized that it would be impossible for me to drag 4 cubic meters of cement screed onto the roof. It turned out to be very difficult. There was no one to help in word or deed, so I canceled this idea of cementing. Moreover, these necessary 4 cubes of screed would have heavily loaded the roof - almost 8 tons... I only had enough to cement the hinges in the slab and also coated with cement screed the place where the bricks covered the gap along the parapet. Everything that is done is for the better, I thought, and in the winter I decided to think about what to cover the roof with instead of cement screed.
It was October 10, 2016, winter was already approaching, and there was no time to tinker with the stove for a long time - the weather did not allow it, the temperature was near zero.
It was decided to preserve the roof by laying a layer of roll material Bicrost TPP - I bought 4 rolls for 4,000 rubles, a bucket of bitumen primer, a gas burner and a gas cylinder, and decided to fuse it. At the same time, this same bikrost layer is the bottom layer in flat roofs - a vapor barrier layer, so it was needed in any case. It’s just that I decided to lay the subsequent layers of the roofing pie on top of it after the winter... At the same time, in the winter I decided to decide on the choice of materials for the roof - leveling the roof horizontally with a cement screed did not work, and the XPS-Wedge requires a horizontal base for installation, so leveling the roof is all it is necessary anyway.
So, I primed it with a primer and applied bicrost. It turned out a little crooked - I did it for the first time, but I thought that special precision was not required here, since there would be upper layers of the roof on top of it. The work was carried out at temperatures near zero, so the rolls rolled out poorly, and ideal laying did not work out:
And then spring came and the roof began to leak... I, of course, did not expect that one layer of this roofing material would save the roof from leaking, and indeed, the roof leaked in the spring. All the slabs were damp and water was dripping from them. March 2017:
The slope of some slabs was towards the house, due to their imperfect geometry, so even the wall of the house began to get wet. Moreover, since my long side of the roof had no parapet and no drainage systems (I didn’t have time to do them before winter), all the water that drained from the roof flowed further along the wall of the garage. The outside was all damp and dirty, which of course didn’t warm my soul... I’ll show you a photo of the wall below.
Therefore, this year (2017) I continued to install the roof. I decided that I needed a parapet on all three sides of the roof so that water would not flow down the garage wall. I also didn’t want to build a cornice and a drain under the cornice; it seemed like the wrong idea to me at the time. Therefore, I decided to install a drain along the long side of the garage, more on this in the following photos.
I made bricks for the parapet with a thickness of 1.5 bricks - so that it would be the same as the side parapets.
Hired builders. They decided that a parapet half a brick thick would be enough, and this is what they came up with. There is excess brick in the photo.
In addition to the traditional gable roof, flat roofing is also becoming popular in individual construction. With the help of modern thermal insulation, waterproofing and roofing materials, you can make a high-quality flat roof for your home.
Flat roofing materials
Ruberoid and its varieties
For flat roofing, rolled materials such as roofing felt and the like are widely used.
- Roofing felt is roofing cardboard with bitumen impregnation and anti-stick coating.
- Fused roofing felt (rubemast)— to attach it, there is no need to coat the roof with mastic, bitumen is already applied to the material, you just need to heat it with a burner. It is based on roofing cardboard impregnated with bitumen. On the lower side the layer of bitumen is thicker.
- Fiberglass rubber (stekloizol, steklomast)— it is based on fiberglass coated with bitumen. Its service life is up to 15 years, it is resistant to precipitation and temperature changes, and can be secured with nails or fusing.
- Euroruberoid - also applied by fusing, is based on fiberglass or synthetic materials, and not roofing cardboard, unlike glass insulation, coated with bitumen with polymer additives.
- Roofing felt is roofing cardboard impregnated with coal processing products, currently used only for roofs of temporary structures, as it is short-lived and fragile.
Regular roofing felt has a low price, so it is popular in private construction. The disadvantages of this material include its low strength.
Important! There are different brands of roofing felt on sale, one of which (marked “K” - roofing) is intended for the top layer, the others (marked “P”) - for lining layers. There is also an elastic roofing felt (“E”) that can be glued to vertical surfaces.
The marking also indicates the type of coating of the material:
"K" - coarse-grained,
"M" - fine-grained,
"P" - dusty,
"H" - scaly,
"C" - color.
The built-up roofing felt is marked “RM” for the lining layers and “RK” for the finishing layer.
Membrane materials
These include plastic mesh-based materials such as EPDM membranes based on synthetic rubbers and resins, TPO membranes containing olefins and polypropylenes, and PVC-based materials. The membranes are thermoplastic.
This material does not require fusing or mastic application. They are heated with hot air and glued with special tapes. For some varieties, it is enough to remove the protective film and then press the membrane to the roof with a roller. Membrane materials last up to 50 years. They weigh less than roofing felt, and their rolls are wider, which allows you to make a roof with fewer joints.
Mastic materials
Mastic bulk materials form a continuous coating without seams, which reduces the possibility of leakage. This includes bitumen mastics and “liquid rubber” coatings based on natural rubber and petroleum products. “Liquid rubber” is not used so often, despite its excellent quality, as it requires strict adherence to temperature and humidity conditions during application. Bitumen mastics come in cold and hot application. Before using mastic, the roof is treated with a primer (primer).
Flat roof installation
A flat roof can be used or not. The roof in use is the one where some other objects are located, such as a greenhouse, swimming pool, recreation area, etc. Designing such a roof is a complex matter, therefore, during self-construction, the roof is most often made unusable. Due to the fact that people sometimes need to climb even onto it, such a roof is covered with a pressure layer of crushed stone, gravel, paving slabs or even grass and soil.
The installation of a roof made of rolled materials can be a “standard pie” or a “reverse pie”.
In the “standard pie” the top layer is waterproofing. If necessary, a pressure layer with a thickness of at least 5 cm is laid on top. First, a vapor barrier is placed on the concrete base of the roof, then insulation, then a slope-forming layer, on top of the screed, primer and roofing material.
The “reverse pie” device is different: first there is a concrete screed, waterproofing from fused materials is laid on it, then insulation (extruded polystyrene foam), then a cement-sand mixture or other coating. The last layer can also be bulk, then geotextiles are placed under it. The advantage of the “reverse pie” is the ability to easily lift the insulation sheets if repairs are necessary.
Methods for fastening rolled materials
Rolled materials are attached using one of the following methods.
- Mechanical - using nails, screws, etc.
- Fused - the material is heated using a gas torch or blowtorch.
- Cold - gluing.
- Self-adhesive materials- just remove the protective layer.
Welded materials
Fused materials, such as rubemast or euroruberoid, are laid as follows.
- First, the bottom layer of material is heated almost to boiling, while the surface of the roof itself is also heated.
- Unscrew the roll one twist using a special metal hook. Typically one person holds the torch while another rolls out the roll. The material must be laid without bubbles or folds.
- When laying each next row, they should overlap each other by approximately 15 cm.
Cold way
Ordinary roofing felt is glued to a roof coated with bitumen mastic. In this case, roofing felt is usually laid in several layers. All layers are laid parallel. Rows in one layer are also laid with an overlap of 10-15 cm, the seams are coated with mastic.
Insulation of a flat roof
Unlike the gable version, which sometimes does not require insulation, thermal insulation of a flat roof is required. It does not create a layer of air, so heat will freely escape from the house. For insulation of flat roofs they are used
- mineral or basalt wool,
- extruded polystyrene foam (penoplex),
- foam concrete.
Suspended ceilings in the rooms will additionally improve the thermal insulation of the house.
Waterproofing and drainage
A flat roof always has a slight slope - 3-5 degrees. This is enough to prevent rainwater from remaining on the roof. Downpipes or fittings may be provided on the roof surface to collect water. Fittings are funnels into which water flows and is then directed into pipes laid inside the building. Such drainage is called internal.
External drainage refers to downspouts installed at the edges of the roof. Through them, water flows into the soil, sewer or septic tank. The most commonly used are plastic (PVC) or metal pipes. Both have their advantages and disadvantages: plastic is more fragile, and metal is susceptible to corrosion. To prevent the pipes from freezing in winter, a thermal cable is laid in them.
In addition to waterproofing materials such as roofing felt, various sealants are used to insulate joints, because these are the places where leakage is most likely. Sealants should not be afraid of water and temperature changes.
Breathable roof
This type of roofing allows condensation to be removed from the space between the layers of the roofing cake. The advantage of this type is the ability to use it not only for installing a new roof, but also for repairing an old flat roof using rolled materials. In this case, the old layer of roofing material is not removed - a new one is fused onto it, thus making it possible to make a slope. The structure of such a roof is shown in the figure. Condensate is removed using weather vanes (roof aerators).
Green roof
Even in a private house, you can make a flat roof green by planting plants on it, both decorative and garden. It is important here to correctly calculate the loads, since the weight of the roofing pie will also be added to the weight of the earth, plants and water that is used to water them. The roofing pie can be standard, but special attention must be paid to waterproofing. Polyethylene, liquid rubber, and various membrane materials are used as waterproofing. The roof structure can be like this (from bottom to top):
- base,
- vapor barrier,
- insulation,
- waterproofing,
- protective layer (geotextile),
- drainage (gravel or crushed stone),
- filter layer (geotextile),
- the soil,
- plants.
A properly installed flat roof not only protects the house from precipitation and cold, but also makes it possible to use its surface. For example, you can make the roof green. To do this, it is necessary to correctly calculate the loads and construct the roof in compliance with the technology.
For residents of Russia, it is associated primarily with industrial, administrative buildings and commercial structures, because the traditional architectural forms of our country are associated with gable and tri-gable structures. The preference for triangular roofs is explained by the harsh climate with high rainfall in winter and summer. The primitive coating available to builders could not cope with the volume of incoming liquid, leading to leaks. In this article we will look at modern technologically advanced and durable materials used for flat roofs.
Creating a flat roof is like making a multi-layer cake, in which roofing materials are layered on top of each other to provide the best waterproofing. This type of coating may include 3-9 layers laid in a certain sequence. However, the costs of arranging this type of floor are 3-4 times cheaper than constructing pitched analogues due to savings on lumber used to create the rafter frame. The structure of flat roofs is as follows:
- The base is treated with a special primer. Concrete slabs or wooden decking serve as the base for the flooring of flat roofs. They are first cleaned of dirt and debris, leveled, and all cracks on the surface are sealed. Then a primer layer is applied, which makes the structure of the material smoother and increases adsorption.
- Screed. A layer of concrete screed is poured onto the pre-prepared base of the flat roof to perform the slope. Sloping is the process of creating a slope to ensure the transfer of rain and melt water to drainage funnels.
- Thermal insulation coating. To prevent heat loss, insulation slabs are laid on the concrete screed. Typically glass wool, basalt fiber or extruded polystyrene foam is used. Some technologies make it possible to make a slope using backfill thermal insulation materials, including expanded clay.
- Screed. After the thermal insulation coating of flat roofs, another layer of screed follows, which protects the insulation from mechanical damage, deformation and wetness.
- Waterproofing. After the second layer of screed, a waterproofing coating is laid, which is created using modern roofing materials laid in several layers. Flat soft roofing is made from bitumen, polymer and bitumen-polymer coatings, installed by fusing or pouring.
Note! A flat roof saves money spent on building a house, and also provides the opportunity to use additional space. The exploited ceiling can be equipped as a summer cafe, a greenhouse, a swimming pool can be installed in it, a lawn can be laid out, or even vegetables can be grown. In addition, projects of “smart houses” that provide themselves with electricity using solar panels installed on flat roofs are gaining popularity.
Installation methods
The construction of a flat roof, which uses technological materials, is highly dependent on weather conditions, humidity and the condition of the base. Projects of private houses with this type of flooring are becoming more popular, so manufacturers are striving to introduce new types of coatings, the installation of which requires less effort, time and skills. Now on the construction market there are roofing materials suitable for roofs of any type, of various sizes. The most common coatings are:
Important! The efficiency and service life of a flat roof depends on compliance with the technology for laying roofing material and proper preparation of the base. In many cases, overlay materials can be installed directly onto the old roof covering without dismantling it, which greatly simplifies the work process.
Bituminous materials
Bitumen roll materials used to cover flat roofs include roofing felt, roofing felt and glassine. They are produced by impregnating roofing cardboard with bitumen mastic, which is a product of the oil industry. These are materials of the previous generation, with a short service life, low strength and poor resistance to low temperatures. They are sprinkled on top and bottom with fine-grained, dusty, coarse-grained or scaly coating to protect against mechanical damage and adhesion of the layers inside the roll. The following types of bituminous materials are used for roof construction:
- Lining. Bitumen-based underlay materials are used to create internal layers of roofing pie and waterproof foundations. They are made on the basis of cardboard with a density of up to 370 g/sq. m. Lining products are cheaper, however, they have less strength and durability. The service life of this type of coating is only 2-3 years.
- Roofing. Roofing materials based on bitumen are used to create the top layer of flat roofs, as they are denser, more durable and resistant to mechanical damage. For the production of such products, cardboard with a density of 350 g/m2 is used. m and coarse stone dressing. The service life of roofing materials based on bitumen is 5 years.
Note! To create a high-quality and durable covering for a flat roof, 3-7 layers of roofing felt or roofing felt are laid: 2-3 lining and 1-4 roofing. The material is laid staggered so that the joints of different layers are located in different places without touching each other.
Polymer materials
Manufacturers developed a new generation of overlay materials for soft roofs, taking into account the shortcomings of earlier analogues. They solved the problems of low resistance to temperature changes, short service life of coatings, and unsatisfactory strength. The result of research and application of the latest developments has been the production of materials from synthetic rubbers and polymer resins. They differ from bitumen-based roofing coatings:
Note! To install polymer materials, you do not need to melt the bottom layer using a gas burner. Laying is done using hot air or adhesive tapes. The soft surface, heated with a hair dryer, is securely glued to the prepared base.
Video instruction
The main structural difference between a flat roof and its pitched counterpart is the low surface slope, not exceeding 1-3%. Precipitation falling on such a plane does not roll down, but lingers on it. And of course, even if there is a slight crack, they leak.
You could say that this is a disadvantage of a flat roof. However, when choosing suitable roofing materials, a negative characteristic turns into an insignificant feature.
Materials for roofing a flat roof cannot be selected based on the principle of “relevance in the new season.” All sorts of fashionable ondulins and flexible tiles are not suitable. And here's why: despite their decorative properties and undeniably good performance when working on pitched roofs, they are not capable of forming a continuous moisture-resistant carpet. And this is how a flat roof should be: absolutely sealed, with a minimum of seams - to ensure that moisture cannot seep under the layers of the roofing pie.
The following options are suitable:
- bitumen roll materials;
- polymer membranes;
- mastics.
All these coatings in the roofing carpet are dense enough to provide good waterproofing of a flat roof, and elastic enough to normally withstand temperature and mechanical influences. Moreover, each material has its own characteristics - in terms of functionality, installation method, durability, cost. Therefore, if you are planning to cover a flat roof, but do not yet know what, then we suggest that you familiarize yourself with the characteristics of the main materials.
Option #1 – bituminous materials
These are materials in rolls that represent a durable base impregnated with oxidized or modified bitumen. Supplied in rolls, 10-30 m long, about 1 m wide.
The following types of bitumen materials exist:
- roofing felt;
- rubemast;
- stekloizol;
- euroruberoid or bitumen-polymer membrane.
Ruberoid
Roofing felt can be called one of the most common waterproofing coatings both in the Soviet period and now. Essentially, it is cardboard impregnated with bitumen. On one or both sides of the roofing material there is a protective bedding (sand, asbestos, talc, etc.). The durability of roofing material roofing is 5-10 years.
Ruberoid has minimal water absorption, so there is no doubt about its waterproofing properties. It is resistant to atmospheric conditions and mechanical influences, thanks to which it can withstand rain, hail, and snow debris.
Unfortunately, roofing felt is not resistant to extreme temperature influences: it melts in the heat (above 50°C) and cracks in the cold. Therefore, one cannot count on long-term operation without repairs. The average lifespan of a roofing material roof is 5-10 years. However, in defense of this material, we can remember that it is inexpensive, and its installation is quite simple. The rolls are rolled out on the roof and glued to the base with bitumen mastic with the seams carefully taped - that's all.
Rubemast
Rubemast, in fact, is the same roofing material, but an improved, more modern version of it. It is also made on the basis of roofing cardboard, but has a thicker bitumen layer on the underside. Due to this, rubemast is characterized by increased plasticity, it is less susceptible to cracking under mechanical stress and temperature changes. Therefore, its service life is longer than that of conventional roofing felt - about 15 years.
Rubemast refers to weldable materials. Its installation is done by melting the bottom layer with a propane torch or solvents.
Stekloizol
Stekloizol (glass roofing material, steklomast) already belongs to slightly different materials, although outwardly it is not much different from roofing felt and rubemast. The only difference is in the filling. Fiberglass or fiberglass coated with bitumen is used as a base in glass roofing felt. A layer of granular bedding is applied on top of the material, and an easily meltable film is fixed underneath. Accordingly, the installation of glass mat is carried out using the fusing method.
Fiberglass, unlike cardboard, is not subject to rotting. They are the “reinforcement” of the material, holding flexible bitumen together and keeping it from cracking. Accordingly, stekloizol is more durable than roofing felt and rubemast. Its service life reaches 20 years.
Euroroofing material
Despite the advantages of all the listed materials, one step above them is Euroroofing felt - the most modern and functional bitumen coating. However, calling it bitumen is not entirely correct; it is more correct to call it bitumen-polymer. The composition of euroroofing felt includes bitumen modified with various additives, for example, pieces of rubber, which gives the final material special flexibility and waterproofing properties.
The basis of euroroofing material is fiberglass (canvas, fabric) or polyester (polyester). These materials are synthetic, do not rot, and are durable. A bituminous binder consisting of bitumen, additives and fillers is applied to both sides of the base. Protective layers of polymer film or bulk materials (shale, sand, talc, etc.) are fixed at the top and bottom of the canvas.
Installation of euroroofing felt is usually carried out by melting the lower bitumen-polymer layer with a burner and then gluing it to the roof. This installation method is typical for coatings with a polymer (indicator) film. Material with an existing self-adhesive layer is more convenient to install. Attaching it to the roof is as easy as shelling pears - just remove the protective film and glue the canvas to a previously prepared place.
You can learn about the characteristics of euroroofing felt using the example of Technoelast material from TechnoNIKOL by watching a short video:
Option #2 - polymer membranes
This type of material appeared in our country relatively recently, but has already gained enormous popularity. Polymer membranes are a qualitatively different type of roofing roll coverings that can withstand mechanical loads, temperature changes and are characterized by increased elasticity. Membranes are supplied in rolls up to 20 m wide and up to 60 m long. Such impressive sizes allow you to create coatings with a minimum number of joints and seams (which can threaten leaks).
Not the least role in the secret of the popularity of membrane roofs is their durability, which is far superior to all other options. Their service life is at least 30-50 years.
Installation of membrane roofs is quite simple, so it can be done in a short time. According to experienced roofers, installation of membranes is 1.5 times faster than laying bitumen roll coverings (under the same conditions).
Depending on the polymer that forms the base of the fabric, membranes are divided into 3 types: PVC, TPO and EPDM.
PVC membranes
The basis for PVC membranes is polyvinyl chloride with a “reinforcement” made of polyester mesh. To increase the elasticity of the material, volatile plasticizers (about 40%) are introduced into the PVC composition, which are gradually released after installation.
PVC membranes are available in different colors, but, unfortunately, they tend to gradually fade in the sun.
During installation, the PVC sheet is first secured mechanically (with telescopic fasteners), and then, laying the second sheet overlapping it, the joints are welded with hot air. Another option is diffusion welding. In this case, a solvent is applied to the surface of the membrane (at the seams), after which the panels are whipped together and a weight is placed on top.
TPO membranes
The production of TPO membranes is based on thermoplastic olefins. For reinforcement, fiberglass or polyester mesh is used. However, membranes of this type are able to work without internal support, so it is quite possible to find unreinforced TPO sheets on the market.
Since the material contains no volatile plasticizers, it is considered safer for the environment than its PVC counterpart. And the most frost-resistant than all other membranes (withstands up to -62°C).
The connection of TPO rolls into a monolithic roofing surface is carried out, as a rule, using a jet of hot air.
EPDM membranes
EPDM membranes are a roll material based on rubber reinforced with polyester mesh or fiberglass. It differs from other membranes in its increased elasticity (about 400%) and lower price.
In addition to pure EPDM, which has a rubber base, composite materials are produced. Their top layer is traditionally rubber, and the bottom layer is flexible bitumen-polymer.
EPDM is insensitive to bitumen and its modifications. Therefore, it is allowed to install membranes on top of an old bitumen roof, eliminating its dismantling and simplifying the repair process.
EPDM is laid by joining the seams with double-sided self-adhesive tape. This method is less reliable than the welded method used for PVC and TPO membranes, and therefore requires the additional use of adhesives. A ballast installation option is also possible, in which the membrane laid and fixed with telescopic fasteners is covered with pebbles, crushed stone, etc.
Interesting information about the characteristics, advantages and features of the production of EPDM membranes is presented in the following video:
Option #3 – mastics
The use of rolled materials, one way or another forming seams at the joints, is not a prerequisite for creating a soft roof. There is an alternative - roofing mastics. With their help, you can create an absolutely monolithic, seamless roof surface with a service life of about 3-10 years.
Mastic is a viscous fluid mixture that, when applied to the roof surface, hardens when exposed to air. The result is a homogeneous monolithic coating, without seams. In this case, we are talking about the use of mastics as materials for creating mastic roofs. But they are also used as adhesives when installing roofing carpet made from rolled materials.
Mastics contain organic binders, mineral fillers and special additives that improve the characteristics of the material. In the air, after being applied to the roof, the mastic hardens within an hour and turns into a smooth elastic film.
Depending on the type of application, mastics can be cold or hot. Cold ones are already ready for use; they can be applied to the roof without prior preparation. Hot – must be heated to a temperature of 160-180°C. Cold mastics have become more widespread, since their application is easier and does not involve the risk of burns. But hot mastics are more economical and harden faster, almost before our eyes.
Depending on the composition, mastics are:
- bitumen;
- bitumen-rubber (with rubber crumb);
- bitumen-polymer (with polymer components);
- polymer.
Bitumen mastics are the simplest in composition; they contain petroleum bitumen, filler and an antiseptic substance. This type of material is not recommended for mastic roofing due to the small operating temperature range.
By adding crumb rubber to bitumen mastic, manufacturers obtain another material more suitable for roofing - bitumen-rubber mastic. Once dry, it forms a durable and flexible coating that can withstand harsh operating conditions and extreme temperatures. Using bitumen-rubber mastics, you can not only create a mastic roof, but also repair many other types of rolled roofs.
Bitumen-polymer mastics are obtained by modifying petroleum bitumen with various polymers - rubbers, petroleum polymer resins, artificial waxes. After drying, they form a continuous flexible membrane with high waterproofing properties. They are also used for gluing and repairing rolled bitumen materials.
And the last option for mastics that can be used for self-leveling roofing and repairing roll roofing is polymer compositions. They do not contain bitumen; their functional properties are determined by the content of synthetic resins and polymers. Roofing membranes obtained using polymer mastics are characterized by elasticity, resistance to UV radiation, and durability.
Polymer compounds are rightfully considered the most durable. What features do they have? And how to apply them to obtain a reliable mastic roof? Watch the video - there are answers to these questions:
What material is better to choose?
After reading the information about the characteristics of each material, there is only one thing left to do - choose based on the desired functional features of the future roof. Do you want to lay the roof yourself? The easiest way to do this is using roofing felt or its modern built-up analogues. The most optimal material in terms of quality, ease of installation and durability is euroroofing felt, especially one that has a self-adhesive bottom layer.
It is not difficult to build a mastic roof, but its service life is limited and is usually 3-5 years. The highest quality polymer mastics last longer - up to 10 years. However, in any case, mastic is an excellent solution for budget construction and repairs, due to its low price.
If you choose a material based on the degree of durability and reliability, without paying attention to the price, then polymer membranes certainly win. Most likely, the installation of these coatings will have to be delegated to specialists, which also entails a general increase in the cost of the roof. But the membranes will last much longer (30-50 years) than any other analogues, so their increased cost is completely justified.