What to put under corrugated sheeting on the roof. Waterproofing the roof of a house under corrugated sheeting. What to consider when choosing a vapor barrier
Read also
Today, it must be the most popular and affordable option for roofing material in our country for covering both residential buildings, and non-residential buildings.
Today the market building materials gives you the opportunity to choose between galvanized roofing sheeting and polymer-coated sheeting.
If you are as roofing decided to use a profiled sheet, then entrust the calculations required quantity material to the professionals of the company from which you will purchase roofing sheeting. You can safely carry out installation work yourself.
In fact, the backing for it is quite simple and entertaining. if you have necessary tool And free time, then you can be sure that using your own hands as a roofing material is not at all difficult.
How to transport corrugated sheets correctly?
To perform loading correctly, the profiled sheets must be placed on a durable and level base, calculating the length reserve for packs with corrugated sheets to avoid bending of the edges.
Ensure that the roof covering is protected from movement and mechanical damage by vehicle. Vehicle speeds exceeding 80 km/h are not recommended. Overclocking must be avoided vehicle and sudden braking.
Loading and unloading profiled sheets
Loading and unloading of bundles with profiled sheets should be carried out using lifting equipment (crane) with soft slings, and if the bundles are more than 5 meters in length, traverses should be used.
When unloading by hand, ideally, a sufficient number of workers will be involved (at the rate of 1.5-2 m of corrugated sheet length per person). There must be a minimum of 2 people. Lifting and carrying material must be done carefully and always in vertical position, to avoid severe bending of the sheets.
How to lift corrugated sheets onto the roof of a building
Before starting roofing work, profiled sheets must be placed on the roof of the building.
You can raise the material by using logs, which are installed in advance from the ground to the edge of the roof. Lift up slowly and only one sheet at a time.
At strong wind It is better to postpone lifting the corrugated sheeting onto the roof, since there is a high probability of deformation of the roofing material.
Then it is necessary to make control measurements. When installing rafter legs it is better to take control measurements of the roof slopes, since in the process construction work There is always the possibility of deviation from the working design.
Do a check: measure the diagonals of the slopes to determine their squareness (the difference in diagonals is allowed within 20 mm, no more). Also check the flatness of the slopes using a level and the maximum deviation. If you allow a deviation from flatness, then subsequently the profiled sheets may not fit together.
Optimal minimum slope for corrugated sheeting as roofing – 12°.
Safety rules when laying profile sheets
Before installing corrugated sheets, it is necessary to carry out treatment with special enamel intended for polymer coatings.
During the installation work To walk on profiled sheets, you need to wear soft shoes, walk only along the deflections of the waves of profiled sheets and in those places where the sheathing passes. The roofing sheeting is secured during installation with self-tapping screws, which are screwed into the decline of the wave. When screwing in self-tapping screws, chips are formed, which must be carefully removed with a brush, since self-tapping screws can rust over time and damage the roofing.
To prevent the possible occurrence of corrosion processes, in places of cuts, chips, and damage to the protective layer, it is necessary to carry out treatment with special enamel intended for polymer coatings. If contaminated areas appear on roofing material, then using a soft brush and washing with a mild soap solution can be cleaned.
Wear gloves while working, as the edges of the corrugated sheets can be sharp.
Do not use after installation of products that are coated protective film. It must be removed during installation work to avoid “sintering” with the polymer layer.
What tool can you use to cut metal?
In order to cut profiled sheets, you can use the following devices:
- Cutting shears with a set of interchangeable knives. They are useful for cutting steel up to 0.6 mm thick by hand.
- A special attachment for a drill, which comes with a set of interchangeable knives. With their help, the drill can be compared with electric cutting shears designed for cutting steel sheets up to 0.8 mm thick.
- Lever shears will be necessary when cutting in any direction metal sheets with a thickness of about 0.6 mm.
- Electric cutting shears allow you to significantly speed up the cutting of steel sheets up to 1.2 mm thick.
Necessary tools for installing a drainage system
- The strip bender is designed for bending high precision gutter holders for drainage systems up to 4 mm.
- Corrugation pliers are necessary so that at the ends drainpipes make corrugated folds that ensure their joining.
- A sealant gun, which is useful both when installing profile sheets and for the device drainage system.
- Staple gun and staples No. 10, which will be needed to secure the vapor and waterproofing.
- The screwdriver attachment required for screwing into wooden knots self-tapping screws with a hex head that secure roofing sheets.
- Rivet pliers that connect products using blind rivets.
- To carefully mark the lathing pitch when performing installation work, you should organize a template for the lathing.
- Additional, auxiliary tools: hammer, tape measure, drill with a set of drills, marker, long strip, cord.
Substrate for profiled sheets
As a roofing material it means installing a heat-insulating roofing layer. Together with waterproofing, it forms a roofing pie under corrugated sheeting, which takes on the function of protection.
It is necessary to correctly select the thickness of the thermal insulation layer and protect it from moisture. If the thermal insulation layer gets wet (at least within 5%), then all its thermal characteristics sharply decrease by almost 2.5 times. This, in turn, leads to freezing of the roof, icing and damage to the finishing of premises, and the formation of ice on outer covering roofs, the formation of mold and mildew, rotting of trusses and sheathing.
How to insulate a roof made of corrugated sheets
Thermal insulation device for attic space
The underlay is laid on the rafters. A waterproofing membrane is laid on the frame. The thermal insulation layer in the rafter plane is laid under the waterproofing layer.
On the room side, the thermal insulation layer is protected by a film or vapor barrier membrane, the joints of which must be sealed hermetically.
The attic itself needs to be covered with wood, OSB or something like that.
To effectively mix air flows under the roof ridge, you need to create a “cold triangle”.
Roofing underlay in non-residential premises (attic)
A cold roof option is suitable for this:
- A waterproofing membrane or film is placed along the trusses.
- The thermal insulation layer should be located horizontally along the ceiling of the room, in which case the attic remains cold.
- On the room side, the thermal insulation is protected with a special vapor barrier film or a membrane, the joints of which are hermetically sealed.
Installation of roof waterproofing from corrugated sheets
If arranged at warm roof, then waterproofing membranes are used.
In valleys, before installing the main level of waterproofing, a waterproofing membrane is opened from bottom to top along the length of the valley.
The main waterproofing is rolled out horizontally along the length of the rafters (avoiding sagging), starting from the eaves to the ridge with the required overlap of 150 mm so that the junction of the rolls falls on the truss section.
Laying sheathing under corrugated sheeting
The lathing is always laid on waterproofing material. It is made from wooden beams 50x50 mm that pass pre-treatment antiseptic, and edged boards 32x100 mm.
The counter-lattice is nailed on top of the waterproofing layer to the rafters from the ridge to the roof eaves. It looks like falling bars 50x50 mm. Afterwards, sheathing boards are attached horizontally to them.
To install corrugated sheets, 32x100 mm boards are used for lathing. To install corrugated roofing, the sheathing is installed in approximately 500 mm increments. Continuous sheathing It is installed in areas under the roofing fence, at the place where valleys are attached, and around chimneys.
Metal is absolutely waterproof, but this does not mean that waterproofing the roof of a house under corrugated sheeting is not necessary. Even when the roof joints and fastening points are sealed correctly and the roof does not leak in these places, condensation still remains on the inner surface metal sheet. And it appears almost every day due to daily temperature changes, atmospheric pressure and humidity. And although waterproofing does not protect the underside of the corrugated sheet from moisture (as some authors claim), it diverts it beyond the roof and prevents the insulation and elements from getting wet load-bearing structure roofs. From the article you will learn about materials for waterproofing, rules for their selection and use.
Abundance of condensate characteristic feature roofs made of corrugated sheets Source decorexpro.com
Waterproofing for different types of roofs
Corrugated sheeting as a roofing covering is used in two types of pitched roofs:
uninsulated;
insulated.
We can also talk about flat roofs, but there a profiled steel sheet is used as a ceiling on which the entire roofing pie is laid. And in this case, according to the design of such a roof, bitumen roll materials and mastics (coating or sprayed), which are located on top of the corrugated sheeting and not under it, are responsible for waterproofing. And in order to move the “dew point” from the inner surface of the sheet, such a roof is insulated from the outside, protecting the insulation from vapors from the side of the room with a vapor barrier, which is spread over the ceiling.
Waterproofing is supplied and combined into one “whole” with the drainage system Source projject.ru
In pitched roofs, multilayer polymer films are used as waterproofing, which have almost completely replaced roofing felt and its more modern analogues (rubemast, stekloizol and others) from this area.
In the “upper” part, the insulation scheme for corrugated roofing is the same:
Rafters legs.
Waterproofing.
Counterrail(distance rod).
Lathing.
Corrugated sheet.
Important! In this scheme, a special place is given to the remote rail. She "asks" air gap in the under-roof space, due to which the vapors are ventilated outside the roof, be it evaporating condensate or excess moisture from the insulation.
Standard ventilation scheme for the under-roof space, cold attic and room Source erp-mta.ru
But the features of installation of the “lower” part of the scheme, as well as the choice of materials for corrugated roofing, depend on the nature of the attic’s operation and even the angle of inclination of the slope. And above all, this concerns the vapor-permeable properties of waterproofing.
On our website you can find contacts construction companies who offer the service of designing and carrying out roofing work of any complexity. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
Materials and features of waterproofing installation
There are two main types of films for roof waterproofing under corrugated sheets:
With limited vapor permeability;
waterproof, but with a high vapor diffusion capacity.
Manufacturers refer to the first type as vapor and waterproofing, the second - as membranes.
The breathable membrane has microperforations Source stroymoda-nk.ru
The choice of type depends on the presence or absence of insulation.
Uninsulated roofs
Metal profiled roofing (corrugated sheets and metal tiles) in an uninsulated roof behave completely differently than slate, ondulin or soft tiles. Waterproofing may not be installed under these materials at all - condensation does not form on their inner surface. Although the manufacturer of Ondulin advises laying Ondutis film to improve the tightness of the roof (and this is understandable - he is an interested person).
As a waterproofing cold roof From corrugated sheets, films with limited vapor permeability are used, that is, vapor barriers. This allows you to “cut off” most of the moist air in the attic from contact with the roof.
To waterproof corrugated sheets in a cold roof, it is better to choose a vapor barrier with an anti-condensation surface Source housetopgid.ru
Note! The attic of a cold roof must be well ventilated using its own natural ventilation system.
Installation of waterproofing looks like this:
Laying begins from below horizontal stripes. The film should sag slightly between the rafters, but no more than 2 cm. The sagging is necessary to collect and “transport” condensate to the eaves.
Preliminary fixation The film is passed through using a stapler.
If necessary increase strip in length, the next section is overlapped. The overlap of the strips is more than 15 cm. The joint must lie on the rafter leg, and it is additionally sealed with tape with a double-sided self-adhesive strip.
The tape is also used to seal joints with adjacent surfaces, chimneys and ventilation system pipes. Source hobbymaniya.ru
Bottom edge of first page put on drip drainage system and secured with tape.
The next strip from the cornice roll out with overlap relative to the previous one. The amount of overlap is more than 15 cm. The joint is additionally taped.
Finally secure film using a strip, which is nailed along the outer end of the rafter leg. The rail must be treated with an antiseptic. A sealing tape is glued to the side of the batten facing the waterproofing.
On slats install the sheathing for corrugated sheets. The pitch of the sheathing depends on the slope of the roof and the type of profile.
This is a work algorithm for one slope - for example, for waterproofing a balcony roof under corrugated sheeting.
For gable and hip roofs there is also a ridge area where the installation of waterproofing on each slope is completed 5-10 cm short of it. This gap is necessary for ventilation of the entire attic and the gap between the roof and the waterproofing.
The gap in the ridge is then closed with an additional element Source rabotayout.ru
For multi-gable roofs, valleys are waterproofed separately:
film roll out in the direction of the valley axis;
fix film with a stapler to the valley boards and adjacent rafters (but no further than 30 cm);
the edge of the waterproofing of the right slope is turned on to the far left
the edge of the waterproofing of the left slope is turned on to the far right valley board 15 cm (excess is cut off);
the edges glued connecting tape and secured to the rafter legs.
This is what the valley waterproofing scheme looks like Source krysha-expert.ru
Important! The vapor-waterproofing film is laid with the smooth side facing the profiled sheet. The rough side (with anti-condensation properties) is turned towards the attic.
If cold attic If they plan to later convert it into an attic, then they choose a membrane for waterproofing.
Insulated roofs
For waterproofing insulated roofs, diffusion or superdiffusion membranes are used.
Diffusion membranes have “medium” vapor permeability. And they may not be able to “cope” with the load of weathering excess moisture from the insulation. Especially if it is a metal roof. And with small roof slopes, due to the small difference in height and pressure between the eaves vent and the ridge, the ventilation intensity may not be high enough to weather the condensate. Therefore for metal roofing They recommend a laying scheme with two gaps under the roof:
Insulation lay down between the rafter legs so that there is a gap of 4-5 cm to their end. The second option is to lay the insulation over the entire height of the rafters, and fill them with a spacer strip 4-5 cm thick.
On top of the distance rod roll out membrane with a slight sag (no more than 2 cm), and secured with a stapler.
Waterproofing scheme metal roof with two ventilated gaps Source domaleto.ru
On the spacer rail on top of the membrane attach the counter rail with sealing tape attached.
The first gap is needed for ventilation of the insulation, the second - for ventilation of the “underside” of the roofing (weathering of condensate).
Important! A scheme with waterproofing with a “regular” diffusion membrane and two ventilated gaps is recommended for roofs with a slope of more than 35°.
Superdiffusion membranes are laid differently - without a gap on the insulation side. They can be used on everyone pitched roofs, covered with corrugated sheets, with a slope of 5.5°. Apart from the absence of a spacer strip, sagging of the membrane and the presence of one ventilated gap, the rest of the installation of waterproofing is similar to the previous options.
Two schemes mansard roof: with full insulation and waterproofing right up to the ridge, with its own small “cold” attic Source gid-str.ru
Main manufacturers and prices
“Intraspecific” choice often depends on cost. And the price of waterproofing under corrugated roofing is influenced by the density of materials, the number of layers, strength for ultimate loads in the transverse and longitudinal direction, water and vapor permeability.
The “simplest” ones are hydro-vapor barrier films. They consist of two, three or four layers. The more layers, the more expensive the material.
Diffusion membranes, unlike vapor-waterproofing films, have microperforation. The “holes” are capable of allowing steam to pass through, but retain water due to surface tension water. If we talk about the differences between “ordinary” membranes and superdiffusion membranes, then the difference lies in the number of holes per unit area and their diameter - the smaller the diameter of the hole, the greater the “height of the water column”, than more holes, the higher the vapor permeability. Naturally, superdiffusion membranes are more expensive than regular ones.
The domestic brand Izospan has one of the largest assortments of films and membranes Source erp-mta.ru
Strength to ultimate loads depends on the density of the waterproofing and the presence of a reinforced layer of polypropylene mesh. Such materials have three or four layers. In addition, they may include as one of the layers:
for vapor barriers and membranes – flame retardant fillers(for roofs with increased fire safety requirements);
membranes have an additional anti-condensation layer or thread soot soaked(with increased ability to retain and remove condensate).
Video description
About choice diffusion membranes watch in the following video:
Below is a list of some main brands roof waterproofing under corrugated sheets, which can be purchased on the domestic market:
Steam and waterproofing for cold roofs. Izospan D (two-layer, unreinforced) – from 1,500 rubles. per roll 70 m2. Izospan DM (three-layer, reinforced, with anti-condensation surface) – from 3,000 rubles. per roll. Ondutis RS (reinforced) - from 2190 rub. per roll 75 m2. Yutafol H 110 Standard – from 2470 rub. per roll 75 m2. Yutakon (four layers, reinforced, with anti-condensation surface) – from 4,500 rubles. for 75 m 2.
Waterproofing diffusion Izospan A – from 1500 rub. for 70 m 2. Ondutis A 120 (with double self-adhesive tape) – from 2070 rub. for 75 m 2. Yutafol D 96 – from 1560 rub. for 75 m 2. Yutafol D 110 – from 2470 rub. for 75 m 2.
Superdiffusion membranes. Izospan AM – from 2070 rub. for 70 m 2. Izospan AS – from 2900 rub. for 70 m 2. Izospan AQ proff – from 3890 rub. for 70 m 2. Ondutis Smart SA115 (with self-adhesive tape) – from RUB 3,100. for 75 m 2. Yutavek 85 – from 3050 rub. for 75 m 2. Yutavek 115 – from 4000 rub. for 75 m 2. Yutavek 135 – from 5000 rub. for 75 m 2.
Video description
For a visual overview of waterproofing materials, watch this video:
Conclusion
Even such a short description different options roof waterproofing under corrugated sheeting allows us to draw a conclusion about the complexity of its design. Taking into account the nuances of choosing materials with the required characteristics and properties, only professionals can design and carry out installation. Errors lead to wetness of structural elements, insulation and ceilings. And this is fraught with the loss of the load-bearing properties of the rafter system, not to mention such “little things” as the loss of the thermal insulation qualities of the roof and ceiling.
Not so long ago, roofing felt made of roofing felt was quite common, but now, when construction progress has gone far ahead, such a material as corrugated sheeting has emerged. His positive traits and cheapness make you attract attention. One of these qualities is the ability to lay this roofing material on another, for example, slate. Many people wonder what will happen if you put corrugated sheets on roofing felt? Let's look at this issue from all sides.
Basic information about corrugated sheets
By corrugated sheeting we mean a sheet of metal of small thickness with a galvanized and painted surface, as well as with some recesses in the form of waves, rectangles or trapezoids.
The recesses located on the surface of the corrugated sheet are made by rolling. This roofing material has quite a few advantages among its “comrades” and few of them can boast of greater strength and durability.
Due to the wavy structure of the sheet, it does not bend, but effective area it turns out to be quite large. High strength ensures good protection the entire structure as a whole and in addition, when laying it, you will not need additional reinforcement of the frame. Galvanized steel and paint coatings, which are contained in the layers of corrugated sheeting, provide it with high corrosion resistance.
In general, upon completion of the installation work of this roofing material, you will be satisfied, because even at first glance experienced designer corrugated sheeting is an aesthetic covering.
Basic information about roofing felt
Why has roofing felt become so popular among developers? It is based on simple cardboard, and as we know, this is not an expensive material, therefore, the finished product becomes quite cheap. This is why it is very difficult for roofing felt to compete.
To make it, cardboard is impregnated with bitumen, which can easily be melted, then a special coating is applied and the whole thing is sealed with refractory bitumen. Please note that cardboard is made from wood pulp and various waste paper. Such a product, based on traditional roofing felt, is not impregnated with anything, and therefore is susceptible to rotting over time.
This problem, of course, should not have been left just like that and was invented quite good decision. This is how Euroroofing felt was created, based not on cardboard, but on fiberglass, fiberglass and polyester. This product is different from traditional material only resistant to decay, and the previous properties remained unchanged.
Now that we have learned about both materials, let's figure out whether it would be advisable to lay corrugated sheets on roofing felt.
Is it possible to lay corrugated sheets on roofing felt?
When laying corrugated sheets on roofing felt, many questions arise and, probably, the most correct one would be “should I get rid of it?” Knowledgeable developers will convince you that this is not necessary, and they will be right. The only disadvantage of roofing felt as a base is bad smell when its surface heats up, but this drawback can easily be eliminated if space for ventilation is left under the roofing being installed. This gap is provided to us by the counter-lattice and sheathing.
Such roofing elements will create a shadow and thereby prevent the bitumen from getting too hot, therefore, there will be no smell. Another important quality of ventilation will be the elimination of condensation that occurs due to temperature changes. In the case of using traditional roofing felt, its protection from moisture will increase operational properties, because, as we already know, it is susceptible to rotting.
IMPORTANT: When installing lathing and counter-lattice, it is very important to do everything correctly, because if you do not provide good ventilation, then the entire roof will very quickly become unusable, despite the quality of the material used.
We already understood that it is not worth tearing the roofing material off the base, but why? The fact is that thanks to these layers, you will provide the roof with additional thermal insulation. Please note that tongue and groove boards will not work as a base for corrugated sheeting. This is due to ventilation problems.
The corrugated sheets must be fastened exclusively with special self-tapping screws. They have a rubber gasket that will provide good sealant. It is worth noting that if the wave height is more than 3.5 cm, the self-tapping screw is drilled into the upper wave, but if the wave is less than this value, into the lower one.
Not long ago, developers summer cottages quite often they used roofing felt as a roof, but now, not a single one good project does not include this material. Why? It's all about the environment. By placing any roofing material on roofing felt, we will in any case allow it to heat up, thereby creating volatile vapors, which in turn will have a detrimental effect on the ecology of the attic space.
In addition to this unpleasant phenomenon, there are some other disadvantages, for example:
- The shelf life of roofing felt is much shorter than that of corrugated sheets
- High labor costs
- When autumn or spring arrives, the occurrence of condensation greatly affects the attic space
Advice: If you do not plan, the device wooden sheathing between the roof covering and the roofing felt, then it is worth getting rid of it and laying steam and waterproofing.
Having studied all the photos and made the decision to lay corrugated sheeting on roofing felt, you should take care of increasing the service life of the entire roof as a whole. To do this we will need the following steps:
- Selection of high-quality roofing material
- Fastening of all roofing material to the base must be done with high quality
- Take into account all the nuances and prepare the surface for installation in advance
- Carry out regular inspections of the roof and, if defects occur, correct them immediately
In conclusion, I would like to say that it is possible to lay corrugated sheets on roofing felt, but in some cases this should not be done. This video will help you study all the information in more detail.
When starting the construction of a new roofing, you can choose any roofing material. However, when we're talking about reconstruction old roof, you have to work with what you have. Professional roofing craftsmen note that a significant part of little-used, commercial and seasonal buildings in Russia over the past 50 years have been covered with roofing felt, which has short term operation. During use, cracks, bubbles and holes appear on this roofing material, then the homeowner realizes that the roof needs to be re-roofed. To save time and money, many craftsmen recommend leaving old roofing felt under corrugated sheeting as a lining. In this article we will tell you whether this can be done.
Ruberoid - roofing roll material, which is made from cardboard with a density of 200-420 g/m2, depending on the type of material. The cardboard is impregnated with low-melting petroleum bitumen, and then sprinkled with armoring powder in the form of stone or granite chips, talc, chalk or quartz sand.In accordance with the density and type of topping, roofing material is divided into two types: lining and roofing. According to reviews experienced craftsmen In roofing felt roofing, 3 “chronic diseases” can be distinguished:
- Low mechanical strength. Due to its low mechanical strength, roofing felt is often damaged during operation by strong gusts of wind, hail, and falling branches.
- Formation of cracks. Penetrating under the armor coating, atmospheric moisture provokes the formation of cracks when the temperature drops below 0 degrees.
- Bloating. Under influence ultraviolet rays and atmospheric moisture, swellings and bubbles often form on the surface of a roofing felt roof, reducing the waterproofing properties of the coating.
- Condensation accumulation. Roofing material does not allow steam to pass through, so moisture condenses abundantly on the rafters, which leads to wood rotting.
Important! The service life of roofing felt as part of a multi-layer roof is 7-10 years, after which the roof requires replacement or reconstruction. In such cases, some craftsmen recommend laying corrugated sheets without dismantling the old coating. They claim that damaged roofing felt can be used as a waterproofing layer roofing pie.
Corrugated sheet flooring on roofing felt
According to professional builders, dismantling the old covering often takes up most of the time and accounts for more than a third of the cost of roof reconstruction. Ruberoid begins to melt at a temperature of 60 degrees, which is why after several years of operation it sticks to wooden rafters and the sheathing that it is almost impossible to remove it. Therefore, many craftsmen recommend laying corrugated sheets without dismantling the damaged coating. However, this technology cannot be used in all situations:
- If the structure being covered relates to economic or production type, is used seasonally or is not heated, corrugated sheeting can be laid directly on the old roofing material covering, because in such a room there is no difference between the external and internal temperatures, leading to the formation of condensation.
- If the structure being covered is used as a permanent residence, it is heated, professional craftsmen It is not recommended to lay corrugated sheets on roofing felt, as it does not allow steam to pass through, which is abundantly generated in such structures. Steam condenses on the underside of this material, causing it to rot. rafter frame roofs.
Note! If the old roofing material is preserved during the installation of a new covering made of corrugated sheets, counter battens and a new sheathing made of timber impregnated with an antiseptic composition are nailed onto it to create ventilation gap, preventing condensation.
Differences between the roofing pie of a “hot” and “cold” roof
Roofing felt waterproofing layer
From point of view building codes roofing felt is not optimal material for underlay waterproofing, although it can still be used. It is laid on the rafters, fixed with tar paper nails, and the joints between the strips are soldered to create an airtight coating. Such an almost monolithic layer does not allow moisture and steam to pass through, which leads to condensation in the rafter system roofs. When installing corrugated sheeting on roofing felt, the following factors must be taken into account:
- Profiled steel sheets They have high thermal conductivity, and therefore become very hot in the sun. The melting point of roofing felt is only 60 degrees, so corrugated sheeting laid without counter-lattice or sheathing can melt a hole in it.
- Due to the difference in internal and external temperatures, steam condenses on the inner surface of the roofing material, penetrating inside wooden elements rafter frame and leading to rotting.
- When heated bitumen material, used as lining waterproofing in thickness, bitumen vapors are formed, which are considered harmful to human health.
Professional roofing craftsmen believe that when reconstructing an old roof, you can leave the roofing material for waterproofing, after first eliminating bubbles and moisture accumulated inside the coating. However, when creating new roof, it is better to use special diffuse membranes that allow steam to pass through.
Video instruction
– a fairly common material lately, because it is different high quality, durability and practicality, along with an affordable price.
However, for the correct and durable installation of such material, it is necessary to observe several important rules: choose the size you need and choose the right backing for it.
Without knowing the basic rules for installing metal tiles, it is impossible to install them efficiently and effectively.
Subsequence correct installation metal tiles:
- before installation it is necessary to install;
- then lay a layer of hydro- and sound insulation on them;
- install counter lathing;
- Only after completing the previous steps can metal tiles be laid.
Metal tiles have few shortcomings in comparison with other roofing materials. The main ones are high conductivity of external noise and poor thermal insulation. A properly selected substrate will help you cope with these disadvantages..
The backing will protect from external influences environment, will give the structure additional strength and durability, prevent leaks and blowing of the roof, give a comfortable atmosphere in the house and significantly reduce the level of street noise transmission.
Can be used as a substrate for metal tiles different materials. Usually for this you will need a sheathing, waterproofing film, rafters and insulation.
There are two main types of roofing substrates, which differ in the type of room heating.
When choosing insulation for a roof, you must first of all take into account the room in which you plan to cover the roof. For residential buildings it is better to choose insulation that is safe for health, For example, mineral wool, cork board or fiberglass. Any type of material is suitable for industrial or non-residential buildings.
The insulation under the metal tiles is laid in a certain way - the slabs are laid in a checkerboard pattern in several layers, this layout allows you to overlap the seams of adjacent slabs, which contributes to maximum protection against heat loss.
The thickness of the insulation sheet should be 5 cm, in which case Laying sheets in several layers will allow you to achieve a thickness of 15-20 cm, which is considered the best option.
Creating a ventilation space
Ventilation under the roof– required element, since it serves several purposes at once:
- removes moisture accumulating under the roof;
- prevents the formation of icy areas and equalizes the temperature over the entire surface in winter;
- prevents the penetration of street heat in hot weather.
A special ventilated roof ridge is designed to remove air, and air flow occurs through the overhang of the eaves. Without properly installing the ventilation system, you will soon encounter a problem high humidity, and as a result, the structure will quickly begin to deteriorate.
Metal tiles on roofing felt
A common type of substrate for metal tiles is roofing felt. This material can be used for an uninsulated attic..
This scheme has a lot of advantages:
- roofing felt – inexpensive substrate, which will significantly save your repair costs;
- installation of the substrate does not require special skills;
- roofing felt – popular building material, so you can buy it everywhere.
However for high-quality installation metal tiles on roofing felt are needed follow certain rules:
- Under no circumstances should sheets be laid directly on roofing felt, this will create favorable conditions to move the structure. It is necessary to make the sheathing in two layers: 1 - along the roofing felt, 2 - under the wave of metal tiles;
- as alternative option you can fill ordinary slats along the installed rafters;
- To prevent fire and simplify ventilation of the room, it is worth constructing ventilation holes.
Roofing installation is best left to professionals. However, if you are determined to carry out all the work yourself, then carry it out according to established requirements. Only in this case can you obtain a durable and reliable design.