Roll roofing: technology, device, deposited materials

Most of the materials for soft roofing are available in rolls. They are intended for flat roofs or pitched, but with a small slope – up to 30 °. Roll roofing materials are rarely mounted on pitched roofs with a slope of more than 15 ° – under their own weight they slide off the slope. They have a low cost, are easy to install, modern materials allow them to be operated without repair for 10-25 years. This is the warranty period that manufacturers give for materials. But how long the rolled roof will be used depends largely on how well it is made. In case of poor work, even the best materials will not save. Therefore, many owners of cottages or private houses prefer to do everything on their own, with their own hands. We will talk about the main points of the device of a roll roof with mechanical fastening (on nails and screws) or using mastic and we will talk further. 

The width of rolled roofing materials is standard – 1 meter, the length of the roll can vary significantly – from 7 to 20 meters, the characteristics change in even wider ranges. So, in order to choose a material for a roll roof, you need to understand the types.

Classification by type of base

The choice of roll material for a soft roof should begin with finding out its basis. They are:

• Baseless. These are materials made from recycled rubber (Izol) or bitumen (Brizol). There is a new material based on butyl rubber (Hydrobutyl). Obtained by rolling crushed raw materials through rollers that form a sheet. Most of the materials have a thickness of 2 mm. They are mainly used in the lower layers of the roofing cake for waterproofing the base.
  

• On the basis of roofing board impregnated with bitumen, sprinkled with mineral powder. The advantage of this material is its low price, the disadvantage is a short service life, poor tolerance to temperature changes. It crumbles at -15°C and +50°C, which greatly narrows the scope of similar materials. Today, roofing material is mainly covered only with outbuildings, and even then not always.
  

• Based on woven and non-woven materials made of fiberglass, polyester. The most expensive roll roofing materials are made on the basis of polyester. They have excellent properties: they have high tensile strength, can be stretched by 30% without loss of integrity, and can also be used in a wide temperature range. Based on fiberglass, a durable, but inelastic material is obtained. When the roof moves, it can come off the base, but it breaks in rare cases. Non-woven fiberglass – the basis is inelastic and fragile, but materials based on it are made auxiliary, lining.
  

The best and most durable materials for roll roofing are based on polyester. Their service life is 15-25 years. They are expensive, therefore they are usually used as a top – roofing – coating, and the lower, lining layers are made of a cheaper material, usually based on fiberglass or baseless materials (as a waterproofing coating).

The device of a soft roof made of welded materials is described here. 

Types of binder

The base of the rolled roofing material is covered on both sides with an astringent protective compound. It could be:

• bitumen (Gidroizol based on asbestos paper, Stekloruberoid);
• tar, bitumen-tar compositions;
• rubber-bitumen compound (Stekloizol)
• rubber-polymer;
• polymeric.

The best characteristics of rubber-bitumen and polymer-bitumen compositions. Some of them are designed for operation in severe frosts – up to -40°C, some tolerate high temperatures well – up to +150°C.

For regions with high temperatures, there are foil-based roll materials for roofing – Folgoizol. A bitumen-rubber or bitumen-polymer binder is applied to the foil from the underside. Due to the reflective properties of the foil, the temperature of the roof will be 20°C lower. The front surface can be painted with weatherproof paints and varnishes. Folgoizol bends well, is cut, nailed with roofing nails. There are roofing (FC) and waterproofing (FG).

appointment

Roll roofing rarely consists of a single layer. Depending on the slope and complexity of the structure, two to five layers are laid. The lower ones serve for waterproofing, heat preservation and sound insulation improvement. They are called “lining”, in the marking they are indicated by the letter “P” (the letter reflecting the purpose of the material is in second place).

The top layer should be more durable, it bears the main mechanical load, it is influenced by climatic and natural factors. For this layer, the most expensive materials are used. They are called “roofing” and are denoted by the letter “K”.

The installation procedure for soft bituminous tiles is described here. 

Types of protective coating

The binders that are used in the production of rolled roofing materials require protection from the effects of weather factors. As a protective layer, sprinkles of varying degrees of grinding are used:

• coarse-grained (K);
• fine-grained (M);
• dusty (P);
• cheshuichataya (Ch);
• special resistant to alkalis or acids.
  

In the marking, the letter representing the type of sprinkle is worth the third. Roll materials used for lining are sprinkled on both sides with fine-grained or dusty powder. Its task is to prevent sticking together in a roll.

Fine-grained or dust-like chips are also applied to the back side of the roofing roll material, and coarse-grained or scaly chips are applied to the front side, which not only protects the coating, but also gives it a more attractive appearance. To give an even more aesthetic appearance, the topping is painted in different colors. Usually it is red, gray, burgundy, brown, green and blue.

Mounting method

Most of the materials for roll roofing are welded onto the base. For this, special burners connected to liquefied gas cylinders are used. With their help, the lower layer of the binder is melted, adhering to the base or already laid material. This technology is used on flat roofs covered with reinforced concrete slabs (for example, in garages).

In private housing construction, flat roofs are very rare in our country. On small houses, this is usually a gable roof, less often a shed roof. The rafter system and lathing of these roofs are wooden, the use of open fire on them is a big risk, and the owners of cottages or small houses are looking for a roll roof that does not need to be welded. There are also such materials. Some of them are fastened with mastic, some are nailed (about them a little lower). There are materials with a self-adhesive layer. All that is needed is to remove the protective film, roll out the material and press it firmly.

Roof base

Welded roll materials are usually laid on flat concrete roofs. In some cases (when repairing garage roofs), they can be laid on a metal base. In this case, the roof material itself is the basis. All that is needed is pre-treatment with liquid waterproofing. There are two options:

• bituminous primer. Suitable for concrete and metal. There is ready-made – in buckets, you can do it yourself – mix bitumen with diesel fuel.
• Cement-based penetrating waterproofing. It contains polymers whose chains block the pores through which moisture seeps through. Such treatment significantly reduces the water absorption of concrete. Its disadvantage is the high price. And the second – in order to fuse roofing material on top, you still have to coat the roof with bituminous mastic from above. Expensive pleasure is obtained. But after such treatment, even if the upper layers let water through, the roof simply cannot flow. If at least a slight slope towards the drain is made (a prerequisite, by the way), the water will leave, almost without seeping down.
  

On pitched roofs with a rafter system, a solid base is required for roll roofing materials. Most often, a continuous crate is made of plywood, OSB, edged or tongue-and-groove boards. But these bases are combustible and it is impossible to fuse a rolled roof on them with a burner. Then materials for rolled roofing are used with a mechanical installation method (slate nails) or glued to the mastic.

There are several more options for non-combustible materials from which you can make a base for a rolled roof – these are flat slate, DSP, GVL and profiled sheet (galvanized). On these bases, special linings and long pointed self-tapping screws with plastic sleeves are used for fastening.

Any prefabricated bases are made of sheet material with a thickness of at least 8 mm, laid in two layers. The second layer is laid so that the seams of the first layer overlap with the sheets of the second (with offset seams).

Materials for roll roofing without fusing

They are not very many, but they are. Fastening method – roofing nails (galvanized with a wide flat head), on a special mastic (usually on mastic for flexible tiles). Some have a self-adhesive base protected by a polymer film. This film is removed during installation by rolling the laid part with a heavy metal roller, trying to avoid the formation of air bubbles.

So, the materials that are attached to the mastic with nails have a self-adhesive base:

• Stekloizol. On the basis of fiberglass or fiberglass, covered with bitumen. It is laid on bituminous mastic. The warranty period is 5 years.
• Ruberoid. Based on construction paper impregnated with low-melting bitumen. Mounted on bituminous mastic. Warranty – up to 5 years.
• Technoelast Solo. A bitumen-polymer binder is applied on the polymer base, it has an increased thickness (at least 5 mm), it can be used without additional lining layers, it has improved fire-fighting characteristics. It is laid on mastic with additional fastening on nails or self-tapping screws, fusion of seams is necessary. The service life is 25-30 years.
  

• Technoelast Titan. Bitumen-polymer binder on a polymer basis. There are three versions of this material. Titanium TOP and BASE – for a two-layer roofing, Titanium Solo – for a single layer. Fastening – mechanical, with fusion of seams, service life – 25-30 years.
• TECHNOELAST-S. A bitumen-polymer binder is applied to the polyester base, and a self-adhesive coating is applied on the underside. It is used to create a two-layer roofing, laying technology – burnerless. An adhesive layer protected by a polymer film is applied on the underside. Before laying, the film is removed, the material is spread, rolled with a roller. The laying temperature is above +15°C, at lower temperatures the material must be heated with a building dryer. Laying on a combustible base (polystyrene foam, wooden base) is possible. The service life is 25-30 years.
  

• Technoelast-Prime. Material for a two-layer rolled roof, glued to the Vishera mastic. The base is polyester fabric, the binder is bitumen-polymer. The service life is 25-30 years.
• Technoelast-Fix. Material for the bottom layer of two-layer systems with mechanical fastening (nails). A bitumen-polymer binder is applied to the reinforced polyester base. The reinforced base gives increased strength, which makes it possible to use this rolled material on pitched roofs with a large slope. Technoelast EKP (surfacing) is then used as the top layer.

As you can see, there is a choice. True, there are only two categories – very cheap and expensive materials, but you can choose based on plans for the near future. If you need a temporary option – to cover the roof, for several years – you can use cheap materials. If roll roofing is arranged for a long time, it makes sense to use expensive ones.

Roll roofing device without fusing

Regardless of what the base of the roof will be, it must be even, dry and clean. No debris or dust. Only pure material.

It is possible to make a roll roof on a pitched roof, but you will have to use certain materials that are designed for this and follow the rules and recommendations. The thing is that roll materials for roofing have a fairly solid mass. Without proper fixation, they slide down under their own weight. To prevent this from happening, special measures are needed. Here are the rules for installing a mechanically fastened roll roof:

• With a ramp slope of less than 15%, the canvas is rolled parallel to the slope. Laying starts from the bottom, moving up.
  

• With a slope of more than 15%, the canvas rolls from top to bottom. So that they do not slip under the influence of gravity, they are usually laid with an overlap over the ridge. If possible, you can roll both slopes in one roll. But in this case, the ventilation hole in the area of ​​uXNUMXbuXNUMXbthe ridge is blocked. Then for attic ventilation it is required to make separate ventilation pipes.
• Note: when using modern materials for a two-layer roofing cake, a perpendicular arrangement of layers is not allowed. Laying occurs only in one direction. In this case, the seams of different layers should be displaced relative to each other. The minimum displacement in the horizontal plane is 300 mm, vertical joints must be spaced at least 500 mm apart. To offset the seams, one of the layers starts with a roll cut in half.
  

• When laying panels, it is necessary to roll them out, taking into account overlaps. Side overlap must be at least 120 mm, end overlap – at least 150 mm.
  

• In those places where there are any structural elements on the roof (outlets of heating and ventilation pipes, dormer windows, junction with the wall, etc.), the roofing carpet is reinforced with an additional layer. Uniflex EPP or Technoelast EPP are recommended.
• When approaching vertical surfaces (on a pipe, parapet, adjoining wall, etc.), the material is glued to the mastic over the entire area, and, if possible, welded.
• The fastener installation scheme depends on the angle of the roof slope, the height of the building, and wind loads in the region. The most frequent installation is in the corners of the roof (25 cm step). This is where the wind loads are the highest. A little less often they put fasteners in the marginal zone (up to 35 cm) – here the loads are average. Fasteners are installed least often in the central area of ​​u50buXNUMXbthe roof (up to XNUMX cm).
  

• Nails are driven in at least 10 mm from the edge.
• Each strip is attached along the edges, and sometimes in the middle.
• The horizontal joints of the canvases are fixed with galvanized steel strips, into which self-tapping screws are screwed, the second option – with nails or self-tapping screws with a washer with a diameter of at least 50 mm.
  

• The perimeter of the roof, along the overhangs, around all structural elements, along the valleys, clog additional fasteners in increments of no more than 25 cm.
• At least 4 nails are hammered around small diameter pipes.

Pipe outlet sealing

In places where pipes or antennas go through the roofing cake, an additional layer is laid. It is glued to the mastic directly on the base. To seal the passage of a round pipe through a rolled non-welded roof, it is carried out using a special rubber shaped element. This is an elastic cap with a rubber skirt. It happens for pipes from 110 mm to 250 mm in diameter.

The rubber cap is pulled over the pipe, lowered so that the skirt lies freely on the base. The bottom of the skirt is smeared with mastic, it is well pressed. Stepping back from the edge of the skirt 10 mm, install fasteners with a step of no more than 200 mm. The junction of the rubber cap and the pipe is filled with an appropriate sealant (for chimneys, the sealant must be heat-resistant).  

Further, roofing material is spread from above, which is additionally fixed around the pipe with nails or self-tapping screws with washers. The fastener installation step is no more than 250 mm, but there must be at least 4 fasteners around the pipe. 

Joint with vertical structures (adjacent to a wall, brick pipe)

An additional layer of underlying material is laid at the junction of the roof with a vertical wall. It must protrude at least 250 mm onto the vertical surface, at least 200 mm must lie on the slope. The entire surface of the additional layer is smeared with mastic, it is well pressed. After that, the upper part is still attached to the metal edge rail. It is attached to a vertical surface with self-tapping screws with washers of at least 50 mm in diameter. The junction of the rail with the wall is filled with polyurethane sealant.

If the roof is insulated, several additional layers can be made to ensure a high degree of tightness (figure above). Each of them goes 100 mm further than the previous one. Each is smeared with bituminous mastic, but the bar is nailed only to the topmost one, although the intermediate ones can be fixed with self-tapping screws with washers in increments of 200 mm.

These are all the main points that are necessary when installing a roll roof without fusing.