Roofing materials in modern design are increasingly moving away from the classic solid-state coatings and at the same time willingly absorb the characteristics of insulating decks. In this development process, there are disadvantages due to the decrease in technical and physical qualities such as strength. But there are also significant advantages that are best reflected by the built-up roof, which combines the properties of a waterproofing agent and a rigid non-rotting sheet.
Roofing cake device
The built-up carpet itself is made of bitumen-polymer components and is laid in the upper part of the roof structure. In the lower layers, the configuration of the arrangement of functional elements may vary. For example, an insulated unexploited roof on a reinforced concrete base is made with several layers of insulators. First comes the vapor barrier, theninsulation, and after it waterproof membranes. The device of this type of built-up roofing does not do without a reinforcing link. In this capacity, web manufacturers recommend using a cement-sand screed, which will act as an intermediate layer between the bitumen primer and the lower insulators. It has its own characteristics and roofing, laid on non-exploited roofs without insulation. In this case, the carpet is arranged without heat, steam and waterproofing, but with slope-forming layers and reinforcement.
Preparation for installation
The rules for laying the built-up coating impose strict requirements on the condition of the roof. It is advisable to carry out a comprehensive sealing of problem areas (cracks, shells, dents) with M150 cement mortar before installation. After it dries, greasy contaminants are also removed from the rough surface, and fine contaminants are collected with a construction vacuum cleaner. Also, using measuring tools such as a level or a laser level, the slope of the roof is checked. As required by technology, welded roofing should be laid on structures with an inclination angle of at least 1.5% when calculating from the valley to the ridge. Typically, slopes are created artificially using wedge-shaped plates - for example, using extruded polystyrene foam. Then the final cleaning of the surface is performed, in which abrasive processing with a grinder can be applied. This need may arise if traces of corrosion or cement laitance are found on the roof. The main thing is not to disturb the structure of the outer protective layers of the rough flooring.
Installation of mounting fittings
After creating the base insulating layers, you can proceed to the device of reinforcing and embedded elements. These include strips of temperature joints, water intake funnels, mechanical retainers and inclined sides. The most important fittings of this type are reinforcement layers, on which the durability, reliability and tightness of the roof will depend. Usually they are installed at the junction of vertical structures on the roof to a horizontal surface. These can be walls, parapets, deflector installations, chimneys, etc. Mounting of the sides for subsequent fixation of the deposited material is carried out using bituminous mastic, primer or adhesive solution. The specific fastening technology will depend on the characteristics of the roofing carpet and the material of the hardware itself.
Expansion joint device
At this point, a cement-concrete screed should be formed, which performs a reinforcing function. And here you can start talking about the technology of fixing the built-up carpet. It is installed by exposure to a high-temperature jet from a burner, the device and principle of operation of which will be discussed later. Since thermal influence can negatively affect the state of the screed, it should first be protected in places where the welded roof will be fastened along the joint lines. These are the expansion joints, which are protected by rolled materials and refractory dressings. The task is to protect the lower layers from thermal deformation. Typically, the manufacturersroofs also produce special tabs for protection, but you can get by with improvised means - for example, planting several layers of high-strength heat insulator.
Gas burner for roofing
Fastening of the built-up carpet is provided by soldering with a primer. Both materials are made on a bitumen-polymer basis, so the action of high temperatures makes it possible to obtain a single hermetic structure. The burner, in turn, acts as a source of thermal action and an activator of the melt. As a rule, these are lightweight and ergonomic devices powered by gas-air mixtures. The equipment is connected through a reducer to the cylinder and, after ignition, is directed by a nozzle to the working surface. Choose a gas burner for roofing should be according to the following characteristics:
- Diameter of the cup (flame nozzle) – 50 mm.
- Weight - 0.5-0.6 kg.
- Tube length - 60 cm.
- Total length - about 100 cm.
- Power - 90-110 kW on average.
These are average values for a typical torch that is suitable for professional paving applications. There are also special modifications focused on melt overlaps. These are so-called seam burners, provided with a pressing press, a damping prevention system and a device for raising the edges of the deck. The design of this device makes it easy to grip the roll material at the joints and at the same time provide a temperature effect on the working area.
Laying roofing material
The roll is heated by the smooth movement of the burner nozzle over the entire contact surface. Initially, the intensity of the thermal impact of the apparatus may not be high enough, so it is desirable to process the first sheet of the web twice. In parallel, it is possible to prepare a funnel with a bituminous primer, which is supplied by the same manufacturer of the main deck. The correctness of the heating will be indicated by a change in the outlines of the technological pattern on the surface of the roof. When it comes to working with adjacent rolls, the torch handling technique needs to be changed slightly. The trajectory of the nozzle movement should be such that additional heating of the areas that will overlap is provided. Next, the laying of the built-up roof begins with an overlap of about 8-10 mm. Moreover, it is important to observe the order of rolling the strips over the entire area of \u200b\u200bthe roof. Overlapping one line on another is carried out from the lower points of the roll to the highest, which will eliminate the formation of the effect of counter-sewing. If laid correctly, rainfall will subsequently flow from the seam to the water collector.
Laying at adjoining points
On the roofs of industrial, public and high-rise residential buildings, as a rule, there are sides and parapets. It is impossible to do without laying the flooring on these structures due to the loss of tightness of the roofing pie as a whole. For a more secure grip on vertical platforms, use side tilt stands. They will allow you to perform flooring at an angle, without losingsingle structure of the carpet. In the process of laying the roofing material, the convergence of the end overlaps between the bottom layer and the reinforcing component should also be avoided. On the vertical surfaces of the parapet, the carpet is wound up by at least 25 cm. At the same time, structures with a height of more than 45 cm can be glued completely with the capture of a horizontal surface.
Features of working in bad weather
It is desirable to work in clear weather without precipitation. If the schedule does not allow you to reschedule the event, then you should prepare canopies and greenhouses in advance. Some modifications of bituminous flooring cannot be laid at temperatures below 5 °C. This applies, in particular, to the Bikrost and Linokrom brands. In other cases, working actions are allowed if the air temperature is higher than the temperature of the flexibility of the material to be laid. In frosty conditions, the built-up roof must be preheated to 15 ° C. Moreover, it should be kept in this mode for at least 24 hours. Special rules for working with gas equipment in the cold are also taken into account. So, in order to increase the safety and efficiency of the melt, it is necessary to use a heater for cylinders with the working mixture. This support will ensure gas pressure stability and optimize gas flow.
Quality control of work performed
After the installation is completed, you can visually assess how well it is done. First of all, you should check for burns,cuts, blisters and waves. All seams must be homogeneous without traces of leakage of the binder solution. The acceptable band of bitumen leakage is no more than 2.5 cm. The quality of the interlayer joints is checked with a slotted screwdriver by bending the edges. This procedure should be performed only after the bituminous mass has completely solidified. In suspicious areas without seams and joints, a cut is made with parameters of 20x5 cm. Based on the taken sample of the welded roof, it is possible to determine whether there is delamination and whether the bonding of the material with the adhesive mixture is ensured. Next, a patch is applied to the control area.
Roof repair
According to the results of technical control, a decision can be made to perform repair and restoration operations. Before their production, the surface of the target flooring is cleaned and degreased. For the deformed area, a special patch is made, which should go 10 cm beyond the immediate damage. The point of the future installation should be heated with a burner and sprinkled with a binder-bitumen-polymer composition. It is important to emphasize that the patch itself must be made from the same material batch as the stacked roll. For example, a soft welded roof "Bikrost" on a rigid structure will quickly lose its adhesive qualities and also deform under physical influences. A properly selected patch will organically enter the structure of the canvas and make the site more reliable. Depending on the nature of the damage, you can do without a patch. The problem is solved by applying a special sealing mastic to the problem area.
Conclusion
The building materials market offers many options for arranging a roofing pie. From solid tiled panels to traditional metal profiles, as well as a huge range of insulating decks. What is the advantage of bituminous coating? As an example, it is worth considering the TechnoNIKOL built-up roof, which is made of a polyester or fiberglass base - it depends on the modification. Unlike conventional types of roofing, such flooring provides a high degree of tightness, lasts a long time and does not give a critical load on the building by weight. In addition, it is lightweight, easy to install and maintainable material. Its cost is also acceptable - on average, 200-230 rubles / sq. m.
