Flat roofs nowadays are undeservedly forgotten and not spoiled by the attention of developers. In private housing construction, they are found mainly in the southern regions, where heavy rains and snowfalls are rare. Hip roofs, on the contrary, have firmly established themselves in the projects and minds of homeowners.
This state of affairs can be explained simply: until recently, builders did not have reliable and durable waterproofing.
Standard roofing felt - cardboard impregnated with bitumen - cannot resist moisture and temperature changes for long. Even a thick 4-layer coating from it has to be changed after 6-8 years.
Today, interest in flat roofs is beginning to grow.
There are several reasons for this:
- Economic benefit. The cost of arrangement is lower than that of a tent structure (simpler design and smaller area);
- Additional usable space. There is the possibility of its rational use (flower garden, playground, recreation area, swimming pool);
- Availability of maintenance and operation (cleaning drains, installing air conditioners, antennas, inspecting coatings, ventilation and smoke ducts);
- A layer of snow acts as additional thermal insulation, reducing heating costs.
- The original appearance of the building.
Types of flat roofs
Strictly speaking, you will not see a completely flat roof on a building. Any of them has a minimum slope of 1 to 4%, necessary for precipitation runoff.
There are four types of flat roofs:
- unexploited;
- exploited;
- green (lawn);
- combined.
Unused roofs are found on industrial buildings.
Operated roofs have found application in public and private construction. They are equipped with recreation areas, cafes and restaurants, and used as parking lots and helipads.
Green (lawn) coverings are made to decorate buildings, as well as when there is not enough space on the site. In addition to the aesthetic function, they perform an important practical task. A layer of plant turf is an excellent heat and sound insulator.
Combined roofs with a flat surface are the most common option. Everyone enjoys comfortable relaxation in the fresh air, surrounded by green grass and flowering plants.
According to the method of drainage, houses with a flat roof are divided into two types:
- With internal drain;
- With external water discharge (along the perimeter of the roof).
Internal drainage is cheaper than external drainage because it does not require a large number of gutters, pipes, funnels and high-rise work to install them. It is more difficult to execute. Errors in creating a slope and poor-quality sealing of joints lead to leaks and damage to the integrity of the protective layer of waterproofing.
In operation, flat coverings with internal drainage are more profitable. In winter, icicles do not grow on the eaves of such a roof. Drainpipes run inside the building and therefore do not freeze. Cleaning debris funnels is easier and easier than hanging gutters.
Device Features
According to the method of arrangement and arrangement of structural layers, experts distinguish two types of flat roofs:
- Classic;
- Inversion.
The classic roofing “pie” is equipped using the following technology:
- a slope is made from cement-sand mortar on reinforced concrete floor slabs;
- lay vapor barrier and insulation;
- lay a waterproofing membrane or roofing felt carpet;
- if the coating is to be used, the waterproofing is protected with ceramic tiles.
Classic flat roof structure
The main disadvantage of the traditional design is the vulnerability of the outer insulating layer from solar ultraviolet radiation and temperature changes.
Working to solve this problem, engineers came up with the idea of an inversion coating. In it, the main structural elements (insulation and waterproof membrane) are swapped. The waterproofing is hidden under the foam, which is protected from external influences by a ballast layer of gravel or tile trim.
Inversion coating design
The technology of work is changing accordingly. A waterproof carpet made of roofing felt or EPDM membrane is glued to the slab or spread on it, fixing it in places adjacent to the parapet.
The slope in this case is created in one of two ways:
- Mortar screed on the slab;
- Insulation, changing the thickness of its installation.
Installing thermal insulation on a flat roof
Water intake funnels and pipes are installed at the lowest points of the slope. In addition to them, ventilation is installed to remove water vapor that accumulates in the area of contact between the vapor barrier and the insulation.
When arranging a covering designed for planting plants, the structure is supplemented with a top layer of waterproofing. Drainage layers of gravel are poured over it, geotextiles are laid and a fertile layer of soil is poured.
In addition to roofing coverings laid on reinforced concrete slabs, designs for houses with a flat roof on wooden beams have been developed.
Construction technology in this case may include the following operations:
- Beams are mounted on the walls in increments of 50-100 cm, fixing them to the masonry with anchor pins. The cross-section of the beams depends on the span width, the design load and can range from 10x20 cm to 15x25 cm;
- OSB slabs are laid along the beams, joining them tightly together;
- Spread the waterproofing membrane in 2 layers, carefully gluing the joints of the sheets.
- Thermal insulation is made from durable (extruded) foam, gluing it to the membrane. A slope for water drainage is created by laying insulation in layers of different thicknesses;
- The heat insulator is protected from above with a cement screed reinforced with mesh or tiled.
Examples of private houses
There are many supporters of flat roofs among developers. They are attracted by the ease of construction, low cost of work and the possibility of placing a site for summer recreation.
A thick layer of snow on a flat roof is not a problem, but additional insulation
The design of buildings with such a roof fits perfectly into the style of minimalism, providing project developers with a wide field for creativity.
Spacious, comfortable and nothing superfluous is the motto of everyone who chooses a house with such a roof. A pitched roof visually weighs down the building, while a flat roof, on the contrary, makes it light and airy.
The appearance of the facade of a one-story house with a flat roof compares favorably with the rather boring variations of the “teremkovy” character.
On it, most often you will not see gutters and pipes, the water from which gets on the walls and spoils the appearance of the finish. Internal drainage is efficient, practical and invisible.
Domestic consumers have long been familiar with the features of a flat roof, and believe that it is used for multi-story government buildings. But modern manufacturers decided to expand their market and found a new area of application for it.
This is surprising, but they appeared with a flat roof, differing in the same set of functional features. It is suitable primarily for areas in which snowy winters and strong wind currents occur at a time concomitant with their manifestation.
Their power will quickly blow away large layers of snow, and the roof will always be clean. And powerful hurricanes will not be afraid of such a roof covering. The fact is that it actually won’t exist.
But this is only part of its capabilities. It will be possible to place many useful buildings for different times of the year. This might be a greenhouse or a small garden, or maybe a dance floor. Other options are available based on the power of the owner's imagination.
But for everything to work out well, it is necessary to study the nuances of creating such structures. Now we will consider many issues related to this topic. To begin with, we advise you to familiarize yourself with photos of houses with a flat roof, which have already proven their suitability for various purposes.
What are the benefits of this roof design?
If we talk only about a private house, then they lie in the following points:
This roofing option will take up a smaller area compared to the most gently sloping modifications. This will help save on the amount of materials.
The process of its construction is noticeably faster than the installation of a gable or hip version. Due to this feature, creating modern houses with a flat roof is noticeably more profitable.
Ensures comfort and safety in performing the necessary rafter work processes. It is quite spacious and difficult to fall off.
It differs from the gable structure in that there is no need to carry out dismantling work from the outdated covering. It can be used as additional waterproofing or protection. This will help save energy and time.
Its surface is suitable for use as an additional area for organizing a flower garden, a cozy terrace, or a greenhouse.
You can mount various transparent elements that help organize a beautiful view of the open starry sky at night or clouds with the sun during the day. And a charming view opens up to admire the rain or a strong storm - there are fans of this state of nature.
Helps to adjust the house to the basics of the minimalist style. He has now gained significant popularity.
What are the disadvantages? - Unfortunately, they exist...
If there is no strong wind, this option generously collects a lot of snow on its surface. You will need to clean it often in order to use the area for your purposes. Sometimes it can lead to noticeable leaks.
Snow will often have to be cleared using mechanical means. They can damage the roof.
The structure of the roof is particularly complex in comparison with other types of forms. For it you will have to organize a lot of drains. They, in turn, often become clogged.
From the pitched version of the roof covering, water drains on its own and this happens very quickly. She does not have time to cause noticeable damage.
On the flat version, water usually stands still and accumulates as rainfall continues. You will have to control the moisture content of the insulation and apply the coating at a small angle so that the water gradually finds the drains.
It will require less materials than a pitched one. But the creation itself is much more complicated. There are many subtleties that not everyone knows about and therefore often this roof option does not turn out the way it was intended.
Because of this, many believe that a flat roof in a private home is not the best option. But now domestic manufacturers have learned about positive Western experience and learned to create the right materials.
And installation specialists adopted methods of high-quality work in this direction, and the situation began to change for the better. This approach has already been able to take root in Russia.
Is it suitable for frame versions of houses?
Yes, today you can see a frame house with a flat roof, more and more often, and it is perceived as commonplace. This roof can be in two directions. For use and without it.
If the roof is to be used, then it is adapted to allow people to move comfortably across its surface. To do this, use a rigid version of the screed or another version of the rigid base. Due to pressure from the movement of people, the roof may leak. In this regard, it is necessary to consider creating reliable insulation from water.
But there is a version without human exploitation. Usually no one walks on it or rarely appears to clean its surface. The load on its area is distributed over the entire surface. But she has one significant problem. Its service life is too short. Although this version is often used due to possible features that satisfy the situation.
There is also a classic version of a flat roof. It is often called a soft roof option. It is formed by a load-bearing slab. The thermal insulation on it is laid on top of the vapor barrier coating. And then the bitumen version of the waterproofing in the form of rolls is rolled out over the thermal insulation.
Due to its advantageous features, this option is used to form such a modification of the roof on a frame house more often than any other.
But experts also highlight an inversion version for forming a flat roof. Sometimes this modification can help create a flat roof home style with the creative mind of an experienced designer. What makes it stand out is that the waterproofing will have to be applied to a waterproofing carpet.
This will help protect against changes in temperature and ultraviolet rays from the sun, which is important if it is located in an open area and under direct access. And this version also allows you to increase the service life - the force of influence on waterproofing from the processes of thawing or freezing of snow precipitation is noticeably reduced. It is quite suitable for installing furniture and assembling a greenhouse.
Important points
To ensure a high-quality arrangement of the flat version of the roof, in any case, you will need to lay the correct version of the carpet. It will help soften the base in case of temperature or mechanical stress. This will help ensure the durability of the coating.
Now, based on the influence of Western culture, Russians have increasingly begun to pay attention to this roof option. The domestic user realized that a cup of coffee at any time on such a roof is a wonderful option. Here the sky is open at all times. And there is constant access to clean air. This is a great option, but a pitched roof cannot offer this.
Of course, not everyone can afford such a roof. Usually the maximum for a Russian is going out to the balcony. But over time it will become a reality for every resident of our country.
If you have the opportunity to create it today, there is no doubt that this is the best option. Today, houses in the Hi-Tech style are gaining great popularity and are mainly based on a flat roof. She has already become their full-fledged companion.
Photos of houses with a flat roof
How quickly time flies! It's been 4 years since I built an unusual country house with my own hands. The house uses many non-standard technical solutions, which were previously practically not used in individual construction in Russia. Firstly, the house is heated using, and secondly, the house has a flat roof.
From the very beginning of construction in 2012, I was constantly told that a flat roof is not for our climate (what kind?), that it will definitely leak (why?), and in general, with such a roof, the house looks like a transformer booth (poor Europeans, they have to live in transformer booths).
But most often they tried to prove to me that snow needs to be constantly removed from a flat roof (I wonder why?). Of course, if anyone wants, you can clean it up, no one is stopping you. But on houses with a flat roof there is no need to remove snow. For example, now I have a snow cover more than 80 centimeters thick on my roof! And somewhere there she hid under the snow.
2. Snow on the roof is an additional and completely free insulation.
By the way, as it turns out, many people do not know that a flat roof is not a plane in the direct sense, but a surface with a slope of approximately 2-4 degrees (in fact, a roof is considered flat if its slope angle is from 2 to 20 degrees). And any flat roof must have a drain. It is more correct to make an internal drain for a flat roof, but you can get by with a classic external one. At the time of construction, I did not have sufficient knowledge to design and implement an internal drain, so I made an external one. The advantage of internal drainage is the absence of pipes on the facade.
3. Summer 2013, just made. A flat roof is significantly cheaper than any pitched roof (at least because its area is on average 1.5 times smaller than that of a pitched roof). With it there is no loss of space and such useless space in the house as the attic. It is simpler and easier to insulate - everything is in the same plane.
Let me remind you of the design of my roof pie (from bottom to top):
1. Prefabricated monolithic floor filled with aerated concrete blocks - 250 mm;
2. Insulation using extruded polystyrene foam - 150 mm;
3. Insulation and creation of a slope using wedge-shaped slabs of extruded polystyrene foam - 0-150 mm;
4. Cement screed - 50 mm;
5. Two-layer built-up waterproofing (top layer with sprinkling).
4. Another huge plus of a flat roof is that it is not afraid of hurricanes. Look at the chronicles of hurricanes and how easily the covering is torn off and the rafter system on classic pitched roofs is broken.
5. In the summer of 2016, I finished all the other work on landscaping the surrounding area and decided to do it.
6. By the way, if anyone doesn’t know, then any concrete floor by default has a load-bearing capacity of at least 400 kg per square meter (usually 600-800 kg/m2). While the snow load for the Moscow region is only 180 kg per square meter. This is the maximum calculated snow load, which in reality is rarely achieved, but it is obvious that any ceiling has a huge margin of load-bearing capacity.
7. Another important advantage of a flat roof is that it has completely sealed seams. While the seams on a pitched roof are not airtight, and if the pitched roof is filled with snow and it begins to melt from below (due to insufficient insulation), the pitched roof will leak (especially at the junction of two slopes - the valleys). Look at the neighboring houses with pitched roofs - amazingly, there is snow on them too!
Why doesn’t a flat roof made using technology leak? Everything is very simple. Because it is insulated!
It is the insulation that determines the durability of the roof. It is known that the roof accounts for an average of 40% of the heat loss of the entire building. If the roof is not insulated, or is not insulated well enough, then the heat will rise, and the snow lying on the upper roofing carpet will melt. When frost sets in, the melted snow will freeze again, and when it freezes, as is known, water expands in volume. These multiple thaw-freeze cycles will eventually break the waterproofing (after 2-3 years) and the flat roof will begin to leak.
8. In the last century, when building houses, they did not think about energy efficiency and saving energy resources, so they usually did not insulate the roof. This led to the fact that the roof waterproofing was constantly being destroyed and the roof was leaking.
If the roof is well insulated, then it has only one “enemy” left - the sun and its ultraviolet radiation. But to protect against this, waterproofing is used with a package, or with special additives (in the case of using). And the most effective way to protect waterproofing from damaging ultraviolet radiation is to make a lawn on the roof, fill it with pebbles or lay tiles. By the way, a more promising waterproofing solution today is a polymer membrane.
A flat roof is even easier to use than a pitched roof. From a flat roof, snow will never fall on your head or tear off your gutters. There is no need to clear the snow, and if you have a lawn, there is no need to keep the gutters clean (all water is filtered through geotextiles and they will not become clogged with fallen leaves).
Therefore, a flat roof is the most reasonable roofing option, especially for a house made of. The main thing is not to violate technology and not to skimp on insulation.
And cleaning snow from a flat roof is not only useless, but also harmful - you can accidentally tear the waterproofing with the sharp edge of a shovel and the roof will begin to leak.
All reports on the construction of a country house with your own hands can be found in chronological order.
For many, flat roofing is associated with urban multi-story buildings, faceless and monotonous. But we are ready to surprise you! A flat roof in a private house will be a pleasant discovery for you if there is not much snow in your area, but the winds are quite strong. The fact is that in winter all snow accumulations from such a roof will simply be blown away. And the main thing is that not a single strong hurricane can tear off a roof that simply does not exist! And a whole ocean of possibilities opens up before you, which you can now build above your head: a cafe, a dance floor, a mini-garden and even a whole greenhouse!
The main thing is to know about all the intricacies of constructing houses with a flat roof, and everything will work out. And now we will reveal all the secrets.
- Such a roof is much smaller in area than the most gently sloping roof. And this means savings on materials.
- Such a roof is built much faster than a gable roof, and even more so a hip roof.
- Comfort and safety of all rafter work. You still have to manage to fall from such a roof!
- Convenient subsequent repairs and replacement of roofing.
- Unlike a gable roof, dismantling the old flat roofing is usually not necessary - this is additional waterproofing and protection. The new pie is made directly from the old one, which saves a lot of time and effort.
- The ability to use the roof as an additional useful area where you can plant a flower garden, make an open terrace and even build a greenhouse.
- The ability to install transparent roof elements (with careful waterproofing), and thus create a view of the night sky.
- Possibility to build a house with a laconic architectural form. Minimalism is at the height of fashion!
And now – about the pros and cons:
- Such a roof generously accumulates snow. After all, he now has nowhere to slide, and the snow itself often becomes the cause of leaks.
- On particularly generous days, the snow will have to be removed mechanically, which often damages the roofing.
- The structure of the roof becomes more complicated: now we need gutters, which also become clogged.
- The difference is that water drains from a pitched roof quite quickly (and sometimes it does get into the under-roof space). But on a flat one it actually stands!
Monitoring the moisture content of the insulation and the general condition of the roof should be regular. - But, despite the fact that much less building materials are needed for its arrangement than for a pitched roof, a flat roof is much more complex in terms of installation. Let's just say that there are many more different subtleties and nuances that are important to know about.
That is why many have fair doubts about the reliability of such a roof. But the European and overseas experience of private residential buildings with a flat roof is successful, and therefore you can safely get down to business.
Just consider these points:
- There is much more snow in Russia than in warmer European countries.
- The only thing worse than snow is the large difference between summer and winter temperatures, which not all foreign roofing materials are designed for.
And here technology decides everything!
What is a flat roof?
So, what acts as the load-bearing base of a flat roof:
- Reinforced concrete slab.
- Roofing sandwich panels.
- Reinforced steel corrugated sheet.
And thanks to the fact that they learned to make a flat roof “breathable”, i.e. with internal ventilation, it has now become possible to use completely non-breathable waterproofing - roofing felt similar to it.
Any roof that we call flat actually still has a slight slope: to one side or specifically towards the drainpipe.
Here is the simplest example of a flat roof for a private home:
Types of flat roofing: non-exploitable and inverted
Of course, unused roofs are cheaper. And the exploited ones, which are correctly called “inversion”, include additional materials.
A separate type of flat roof of a residential building is exploitable. Those. the one on which people will walk and what objects will stand. This is the same garden, or sports ground, or summer cafe. All this creates considerable loads on the roof, and therefore its design is already different from that which is intended only to protect the house from precipitation.
So, the main difference in the design of traditional and inversion roofing is that in the first, the thermal insulation layer is located under the waterproofing, which is quite logical, and in the second, it is above it. But in the second option, the waterproofing is more protected from ultraviolet rays and temperature changes. This design is more durable and functional: you can safely lay out a lawn or lay paving slabs on it.
And now in more detail.
Unused roof: standard pie
But a person can also occasionally climb onto an unused roof - for the same repairs, for example.
Those. in a traditional flat roof, the top layer is waterproofing, and it is this that is exposed to all mechanical and temperature loads.
A separate type of it is a roof with a pressure layer, which is designed so that a person can walk on it from time to time:
Inversion roofing: reverse pie
The standard slope of an inversion roof is 5-7%. The inversion method assumes that the thermal insulation layer is already placed on top of the waterproofing, which now also serves as a vapor barrier.
Moreover, the pie of inversion flat roofs can be very different. It all depends on what you are going to arrange on the roof: a terrace, a mini-pool (and this is not uncommon) or a garden. But the base will still be common: a monolithic screed is made, which levels the entire surface, then waterproofing is laid and the whole thing is covered with insulation. And on top is a cement-sand mixture or rubber coating.
Note that active use of the roof means frequent damage to the insulating layer, which is why moisture makes its way to the insulation and freezes in winter. Over time, the entire roofing pie deteriorates, and therefore a flat roof cannot do without a ventilation system.
A cement-sand screed can even better distribute the pressure layer on the heat insulator, but it must be additionally reinforced with a mesh to prevent cracking.
Subtleties of flat roof insulation
A layer of thermal insulation for a flat roof is mandatory. For comparison: a gable roof is insulated only when a residential attic is installed underneath it, and in all other cases, a maximum of mineral wool is laid on the attic floor. But for a flat roof, insulation is always necessary.
The fact is that without a heat-insulating layer in a flat roof, condensation will constantly appear on the ceiling in the house (such a roof will turn out to be the cold part on which water vapor will rush). And this is bad not only because repairs will have to be made, but also because the entire structure deteriorates.
You can insulate a flat roof both from the outside and from the inside - the difference is small. What is more important is how many layers of insulation a particular roof needs – one or two.
Thermal insulation materials must be attached to the base of the roof mechanically, either with screws or dowels, or with adhesive. Sometimes the fastening is not used at all if the heat insulator is located outside and paving slabs or pebbles press on it.
Why two layers? The fact is that the first layer of thermal insulation on a flat roof acts as insulation; it is from 70 to 200 mm thick. And the second, from 40 to 50 mm, is designed to distribute all the loads. And it is important to calculate the thickness of both layers accurately, based on the climatic characteristics of the area and the future use of the roof itself.
With double-layer insulation, all joints should be spaced apart, in a checkerboard pattern, so as not to overlap each other. Moreover, in the places where the slabs adjoin the walls and parapet, it is additionally necessary to make heat-insulating sides. A cement-sand screed can even better distribute the pressure layer on the heat insulator, but it must be additionally reinforced with a mesh to prevent cracking.
Proper drainage system
But this is already a difficult task. Flat roofs are just bad because they are completely open to rain. But everything can be solved! The main thing is to properly organize the drainage, and for convenience, we have explained this issue for you in the following schematic illustrations:
Internal ventilation device
Another important point when arranging flat roofs is ventilation. The fact is that if moisture accidentally gets into the insulation, it no longer evaporates - it only accumulates. As a result, the heat-insulating material rots and the waterproofing swells. And there are many reasons for leaks: damaged waterproofing, mechanical damage to the top layer of the roof, cracks and damage from frozen water.
A wet thermal insulator is also bad because it causes bubbles and cracks to appear on a flat roof in the summer heat - all due to the active evaporation of water. As a result, the roof covering also collapses. And if moisture gets under the old screed over time, then the entire roof begins to peel off. This is why a flat roof must “breathe”.
For this purpose, so-called aerators are used. They look like simple plastic or metal pipes covered with umbrella caps. They should be located evenly over the entire roof area, preferably at its highest points. The essence of this mechanism is that different pressures are created inside the roof and the air begins to create currents, simultaneously taking with it all the excess moisture vapor.
In practice it looks like this:
In addition, in any living space, water vapor rises up to the ceiling. Moreover, they often successfully overcome this barrier (the water molecule is very small) and end up in the insulation, which is bad for it. This is why vapor barrier is required. And not the kind that is usually used for attic insulation, but a dense one, made of high-quality polypropylene or polyethylene. The bitumen membrane is even more reliable.
Choosing a suitable roofing covering
So, what is used as a coating for such roofs?
Option #1 – bitumen and polymer-bitumen materials
Such roofs are the least expensive for owners of private houses. We are mainly talking about roofing felt and euroroofing felt. These are rolled roofing sheets, the base of which is synthetic fabric, and the sides are bitumen. As an elastic and frost-resistant material, bitumen serves as excellent protection and waterproofing.
Moreover, laying bitumen roofing on a flat roof is absolutely simple; you only need a gas burner. The rolls are easily fused together.
But such a roof has a significant drawback - fragility. And another thing is that roofing felt does not breathe at all, i.e. It is vapor-tight, and therefore it is necessary to arrange ventilation for such a roof, unless you want the insulation to rot within a year:
Option #2 – liquid rubber
Such roofs have the great advantage that they do not contain any seams. As we have already said, the disadvantage of a flat roof is, first of all, that snow accumulates on it, which then causes leaks.
But there are some subtleties here. So, you need to take only two-component liquid rubber for a flat roof, preferably the highest quality one. And it is extremely important to apply this material correctly to a flat roof: evenly, avoiding unnecessary layers and saving in certain places. So, where the paint was applied unevenly, problems should be expected within 8-10 years.
Option #3 – PVC, TPO and EPDM membranes
Roofing membranes are valuable as a covering for flat roofs because they allow steam to escape. After all, no matter what kind of vapor barrier is used, moisture still, at least a little, gets into the insulation, not only from below, but also from above - after heavy rains, for example.
There are three types of membranes for installing such a roof: TPO, PVC and EPDM. The most popular is PVC membrane, which is also the most flammable. An EPDM membrane is more durable and affordable, but if mechanical damage occurs in it, nothing can be done to fix it, whereas a PVC membrane can only be melted with a hairdryer. In addition, the joints of the EPDM membrane must be glued with a special tape, which is much less reliable than soldering PVC sheets.
But the cheapest membrane in its sector is PVC. But it has such significant disadvantages as low resistance to ultraviolet rays and fear of contact with bitumen, various oils and even polystyrene foam, otherwise the service life will be significantly reduced.
Gluing EPDM membranes requires professional skills. TPO membrane, like PVC, is also welded with hot air. The best is not afraid of ultraviolet radiation, is more chemically resistant and can be laid directly on polystyrene foam or an old bitumen roof without geotextiles. But its service life is shorter than that of EPDM, so for installing a flat roof on a residential private house, we recommend using a PVC membrane.
So, a flat roof device with a PVC membrane is traditionally made like this:
- Step 1. We arrange a monolithic floor slab.
- Step 2. Place a tear-resistant vapor barrier film.
- Step 3. We make a bend from insulation or screed.
- Step 4. Place insulation. In private construction this is usually 35 density foam, and on top is 50 mm XPS, which is even stronger.
- Step 5. Now geotextiles, 300-500 g per square meter.
- Step 6. Let's move on to waterproofing - this is a PVC membrane. The insulation density is enough to allow walking on such a roof. But, if you plan to make an open terrace on the roof, then you need to continue the pie further.
- Step 7. Lay the geotextile again - now directly on the membrane.
We lay rubber tiles or reinforced screed 5-7 cm, on which we already lay paving slabs. To make a screed, you need ballast.
And such roofs are made of rubber, polymers or even foil. Unlike bitumen, they are durable, fire-resistant and adhere firmly to the base. A slight slope is achieved using expanded clay concrete or concrete screed.
How to achieve 100% waterproofing?
The main task when installing a flat roof is to make all joints and junctions as airtight as possible. After all, such a roof is most affected by moisture, hail, temperature changes and wind-blown debris. Therefore, the sealants used to seal such joints must be of high quality and resistant to any influences. This is also a kind of expense that has to be incurred.
For the same purpose of waterproofing, it is recommended to make the slope of a flat roof at least 2%. Few? In fact, this is quite enough so that all atmospheric moisture does not linger on the surface, but flows down into funnels and pipes, and from them into the septic tank, soil or sewerage system. Therefore, even at the design stage, you need to carefully think through the future drainage system.
Moreover, the drainage system itself is made both internal and external. Thus, internal drainage is made up of fittings - funnels located throughout the roof, which receive the flowing water and direct it into pipes that go through the buildings, but are isolated from the living quarters. The only disadvantage of such a system is that the pipes become clogged with small debris and leaves, for which it is advisable to equip them with special filters and periodically clean them.
External drainage systems are already attached to the outer walls of the building. These are, of course, easier to clean when they become clogged, but in cold weather they often freeze over. For this reason, it is customary to additionally supply them with electrical heating in the form of cables.
As for the material for the internal and external drainage system of a flat roof, PVC or metal is quite suitable. Both options have their pros and cons. Thus, polyvinyl chloride does not corrode, but is more brittle than metal.
To prevent gutters from freezing in winter, equip them with roofing thermal cables.
Green area on the roof: fashionable and environmentally friendly
Greenery and recreation areas are often lacking not only for residents of the “concrete jungle”, but even for owners of private houses. The thing is that it is not always possible to leave the same beautiful garden furniture in the yard of the house, and beautiful rare flowers in the garden flower bed are often trampled by pets. Therefore, it is not surprising that the green area on the roof has become fashionable among cottage owners. Especially if the access to it comes directly from the bedroom and no one else can disturb your morning peace with a cup of coffee.
There has also become a fashion for some cafes to make the roof flat and put a small greenhouse on it. All the greens go straight to the table! And it’s profitable, because it’s not so easy to bring fresh dill or onions to the kitchen, and it’s economically profitable - there’s somewhere to send kitchen waste. And it is difficult to understand who borrowed this idea from whom: enterprising residents of private houses with a flat roof, or the best minds in public catering. But the fact that such an arrangement of closed ground is beneficial is a fact: rodents will not dig under the beds, insects and pests will not reach (as well as pests in the form of neighbors), and the fact that it is always a little hotter on the roof is only a plus for the same tomatoes. But the main thing is to correctly calculate the loads on such a roof during construction!
And the roofing pie is often standard: waterproofing for the ceiling, thermal insulation, geotextiles, drainage and geotextiles again. And on top you can use both soil and beds:
Or in this version for more powerful floors:
A flat roof is a huge scope for any imagination. Designers and architects love to bring to life a variety of projects for her: a garden, a greenhouse, a jogging track, a mini-beach with sun loungers, and much more. Some craftsmen even manage to make a parking lot on it!
Swimming pools and tennis courts, playgrounds and solariums, gardens and walking alleys, but only on the roof! Houses with a serviceable roof have such opportunities: in modern suburban construction they actively compete with traditional houses and offer additional space for operation.
The portal site presents a selection of the most popular projects of houses with a flat roof. Their expressive, laconic architecture and the ability to expand functionality due to an open area on the roof will certainly resonate with owners of cramped areas and adherents of modern European design.
Project of a three-story house ""
Area 473 sq.m.
Roof type flat
Dimensions 19.8*18.7 m
Garage 2 cars
Number of bedrooms: 6
Number of bathrooms: 7
The exploitable roof of the Vesconti project is suitable for leisure of all generations. Children will be happy to organize a play area here, young people will set up a ping-pong table or organize a party, and the older generation will install upholstered furniture for an outdoor recreation area.
Area 678 sq.m.
Roof type flat
Dimensions 26*25 m
Garage 2 cars
Number of bedrooms: 3
Number of bathrooms: 5
Project of a modern two-story villa with wood trim in a horizontal layout, open terraces and a built-in garage for two cars.
At the ground floor level, the left side of the villa is occupied by a garage with technical rooms, and the right side is occupied by the combined space of the living room and kitchen-dining room. Adjacent to the living room are: staircase and distribution halls.
Three bedrooms, each with its own dressing room and bathroom, are located on the second floor. The office is also located here. Each room on the second floor has a corner panoramic window and access to an open terrace.
The villa is designed for permanent residence of a family of 4-5 people.
Area 468 sq.m.
Roof type flat
Garage 2 cars
Number of bedrooms: 3
Number of bathrooms: 4
Project of a modern villa with brick finishing, a cantilevered second floor and a built-in garage.
L-shaped in plan, the villa is designed to accommodate a family of 3-5 people and has a simple and convenient layout. At the ground floor level, one wing of the house is occupied by a garage for two cars and technical rooms. The other has a combined kitchen-dining room and living room with access to the terrace.
On the second floor there is an office and three bedrooms, each with its own dressing room and bathroom. The parent's bedroom with an obliquely cut loggia “hangs” in a cantilever above the living room. On the roof of the garage there is an open terrace with a solarium and a barbecue area.
Area 450 sq.m.
Roof type flat
Dimensions 23.2*15.4 m
Garage 2 cars
Number of bedrooms: 6
Number of bathrooms: 6
Norden belongs to eco-urbanism, is distinguished by minimalism in decor, functionality and efficiency of planning solutions. The project is sold together with a design project for all premises, including layout options for the usable roof, which occupies more than 160 sq.m. and is divided into three independent functional zones.
The project is very spacious and ideal for a large family6. There are not only 4 isolated bedrooms for the owners of the house, but also 2 rooms for staff. All technical rooms are designed here - a boiler room and a garage for 2 cars. A spacious terrace on the first floor and a balcony with a garden on the second will allow you to save directly on the area of the acquired land plot, organizing quality outdoor recreation within the boundaries of the cottage itself.
Project of a two-story house " »
Area 486 sq.m.
Roof type flat
Garage 2 cars
Number of bedrooms: 3
Number of bathrooms: 4
Project of a two-story villa with corner panoramic windows, natural stone finishing and a built-in garage for two cars. The villa is designed for permanent residence of a family of 4-5 people.
At the ground floor level the house is divided into two parts. The right one is occupied by a garage and technical premises, the left one is a cross-shaped combined space of a hall with an internal main staircase, a living room, a fireplace room and a kitchen-dining room. The dining room has its own exit to the garden.
On the second floor there are four bedrooms united by a spacious hall, each with access to its own balcony. The bedrooms are interconnected with separate dressing rooms and bathrooms with natural light.
Area 573 sq.m.
Roof type flat
Garage 2 cars
Number of bedrooms: 4
Number of bathrooms: 5
Project of a two-story house with continuous glazing, open terraces and an attached garage for two cars for a family of 4-5 people.
A one-story garage with a usable roof is attached to the main two-story volume of this house.
The presentation group of premises is located on the ground floor and opens onto a terrace running along the main volume of the building. This is a spacious hall with an internal main staircase, a living room with a double-sided fireplace and a kitchen-dining room. On the ground floor there is a guest or maid's room with a separate entrance.
Three bedrooms and an office, located on the second floor, are united by a beautifully lit hall and have access to balconies and a terrace located on the roof of the garage. The children's bedrooms are interconnected with separate bathrooms, the parents' bedroom has a dressing room and a bathroom with natural light.
Area 123 sq.m.
Roof type flat
Dimensions 16.14*12.94 m
Number of bedrooms: 3
Number of bathrooms: 2
Project of a one-story house with wooden trim and sloping concrete walls enclosing a terrace next to a group of bedrooms. The house is designed for construction on relief, has an outdoor pool and is designed to accommodate a family of 3-5 people.
The planning solution for this house involves dividing it into two parts - presentation and private. The presentation room is a spacious living room with a fireplace area and a kitchen-dining room. The kitchen has a work island and an adjacent food pantry. The presentation part of the house opens onto a terrace with a swimming pool and an outdoor solarium.
The private part consists of two children's bedrooms and a parent's bedroom, each with access to a terrace. At the same time, the parent bedroom has two opposite exits - to the side terrace, enclosed by concrete walls, and to the main one, with a swimming pool.
Project of a three-story house ""
Area 357 sq.m.
Roof type flat
Dimensions 14.7*12.9 m
Number of bedrooms: 4
Number of bathrooms: 3
The minimalism of "Alicante" will appeal to many buyers. Simple, but at the same time harmonious, this project will fit into a site even with modest dimensions. And the ergonomics of the interior makes the house functional and comfortable for a family of 5-6 people.
Area 214 sq.m.
Roof type flat
Dimensions 11.66*14.66 m
Garage 1 car space
Number of bedrooms: 5
Number of bathrooms: 3
Project of a modern two-story house with a built-in garage, decorative shutters on the facade and colored exterior lighting.
The breading solution of the house assumes that a family of 5-7 people will live in it permanently. On the ground floor level there is a spacious living room with a corner fireplace and access to the terrace. Adjacent to this is the open kitchen/diner with a work island, dining table and large food pantry. At the ground floor level there is a bedroom for older family members, which can also be used as a guest room.
Three children's rooms - each with its own mini-office, but with a common dressing room and bathroom, are located on the second floor. There is also a parent's bedroom, designed as a single block with a bathroom and dressing room and having access to a balcony.
