The construction of roofs today has become much more interesting and progressive than it was recently. The reason for this is not only the use of modern technologies in the conduct of construction work, but also the introduction of innovative materials, one of which is bituminous roofing mastic. With its creation, the need to use roll materials widely used in the repair or reconstruction of flat roofs has been reduced. This roofing material can provide effective waterproofing of the surface. In this article we will describe what bitumen mastic is: types, characteristics and features of which are of interest to many.
What bitumen mastic is
Mastic roofing bitumen is an artificially created material that is nothing more than a mixture of organic substances with astringent properties, natural mineral additives and fillers of various sizes. In the composition of the substance, antiseptics and herbicides can be introduced. The output is a viscous homogeneous mass, which is easy enough to pour on a flat surface. After hardening, the bituminous mastic for the roof is like a monolithic material resembling rubber in appearance.
Appearance of the roof covered with bituminous mastic
The composition of the mastic is different. Depending on the substances included in it, two-component and one-component mastics are isolated:
- One-component mastics are produced from certain solvents. They are a complete product that can be used immediately. It sets in the course of volatilization from the solution of the volatile solvent contained in it. Such mastics are sold in sealed containers, which avoids premature hardening of the material. Use such mastics should be within 3 months of production. An exception to this rule is bituminous mastic for polyurethane roofing. For its solidification, water vapor, which is contained in the air, is necessary. Due to the absence of solvent in the polyurethane mastic, there is no shrinkage during its polymerization. In a sealed container this material can retain its properties for up to 12 months.
- Two-component mastics consist of two separate substances that can be stored separately for more than a year. This makes it possible to prepare the material in advance. The working composition can be obtained only by mixing the two components in one mass.
So put mastic on a flat roof
What are the useful properties of
mastic? If you compare with roll materials, then bitumen based roofing mastic has a number of advantages, most important of which is the formation on the surface of a film or membrane, which is absolutely waterproof. The technical characteristics of the roll and mastic roof are similar, but when the roof is covered with mastic there are no seams, which reduces the risk of leakage to a minimum. In this case, all mastic coatings have the properties described below:
- Stability under the influence of aggressive environmental factors.
- Light weight.
- Good elasticity.
- High enough strength.
- Immunity to corrosion.
- Resistant to the action of oxidants and ultraviolet radiation on the material.
As a drawback, it can be noted that the roof for applying mastic should be absolutely flat and even, as the liquid substance is distributed over the surface by a thin layer under the influence of gravity. Even with a slight inclination, the substance simply flows to one side. For alignment, a larger quantity of solution is required. Several to level this effect helps the addition of thickener or cement. This is done if the slope is more than 12 degrees or high( more than 25 degrees) air temperature.
In this package, asphalt mastic for roofing
is sold. What are the types of
roofing mastics? In order to classify roofing mastics, the following important features needed to be considered:
- Method of use( cold and hot).
- Purpose( roofing-insulating, waterproofing-asphalt, anticorrosive, glued).
- Method of solidification( curable and non-curable).
- Kind of binding agent( bitumen-polymer, bitumen-latex roofing, chlorosulfonopolyethylene, polymeric, butyl rubber).
- Type of solvent used( with water content, organic solvents, liquid organic substances).
- Element composition( single-component and two-component).
Current mastics have properties such as water resistance, biostability and enhanced adhesion. These materials are successfully used on newly constructed roofs and old roofing surfaces. With the help of them you can:
- Stick the roll and waterproofing materials for the roof.
- Install a protective layer on the roof.
- Make the installation of a fully mastic roof.
- Construct a vapor barrier.
- Carry out anti-corrosion protection from false roof on the roof.
According to the current GOST "Mastic bituminous roofing hot", the material must have the following mandatory properties:
- To be distinguished by ease in the process of application and use.
- Possess good bonding ability for use on horizontal and vertical surfaces.
- To form an elastic coating.
- Do not form cracks when cured.
- Be durable enough.
- Resist fluidity and gradual shrinkage.
- Do not lose flexibility even at low air temperatures.
- Easily succumb to tools during mastic roof installation work.
- Do not lose quality in circumstances of increased humidity.
The above mentioned advantages report that bituminous roofing mastic is an interesting building material for the construction of roofs with a small slope of the roof slope.
Systematization of mastics according to the type of binding agent and other parameters
As already mentioned, mastics by type of binding agent are bitumen, bitumen-polymer, tar and rubber-bituminous.
As fillers for roofing mastics, the following is usually used:
- Short-fiber mineral wool.
- Conventional asbestos or its dust.
- Thin sheet dusts from limestone, bricks, quartz, etc.
- The ash is combined or appearing during pulverized coal combustion of mineral fuel.
Fillers are needed to improve the characteristics, which should have a cold roofing mastic, namely:
- Hardness and density.
- Reduces brittleness at too low temperatures.
- Reducing the specific consumption of binders.
The use of fibrous fillers makes it possible to reinforce the mastic, making it more stable for bending.
Roofing mastic according to the method of solidification is divided into curable and non-curable.
By type of diluent, they can be divided into mastics:
- Water-based roofing based on bitumen.
- Containing solvents based on organic compounds.
- Containing liquid organic substances.
So after solidification, the bituminous mastic looks
Properties of bituminous mastics
All roof mastics, having poured out in the air, polymerize within one hour. In the course of this, a flexible smooth surface is formed, which has excellent stability in relation to various atmospheric influences. The material obtained in the end has excellent water resistance, good adhesion and, in certain cases, biostability.
The following requests and standards are applied to bitumen roof mastics:
- The structure of any mastic must be uniform, it should not contain particles of fillers or binding impregnation.
- Mastics should be easy to apply on the surface. They should contain no harmful volatile substances that could be released during use or their number should not exceed the maximum permissible standards.
- Although hot, even cold mastic should have high water resistance and biostability.
- All bituminous mastics should have a heat resistance of at least 70 degrees.
- They should pretty firmly stick the roll materials.
In addition to mastics, very high requirements are imposed on their service life. The physical and mechanical parameters of the material must be stable throughout the manufacturer's declared service life.
Technology of applying mastic to the roofing surface of
On the quality insulated surfaces, a liquefied emulsion paste based on bitumen is applied before coating with mastic. It plays the role of a primer, at times increasing the adhesion of the mastic to the concrete base. Then the whole surface is covered with the main several layers of bitumen mastic. The number of such layers directly depends on the angle of the roof slope.
Among these layers there must be a so-called reinforcing layer. It is made of mastic with a special reinforcing composition. On top of it, another layer of mastic is applied. It makes it possible to strengthen those places where the periodic accumulation of water is most possible. At the final stage, a layer of protection is applied, which can be made of lining material, gravel, coarse sand. It can even be the usual coloring of the surface with a protective paint.
Characteristics of bitumen mastic
Roofing bituminous mastic is a material in which I have artificially synthesized bitumens. They appear as a result of deep processing of oil from its resinous residues. These resinous substances strongly change their viscosity when heated. The color of bitumen is black or dark brown. According to the degree of viscosity, the builders distinguish several varieties of bitumen:
- To impregnate the roll materials for the roof, it is customary to use liquid compositions based on bitumen.
- Bituminous mastics themselves roll materials, varnishes are made from solid and semi-solid bitumen.
Appearance of a roof covered with bituminous mastic
Bituminous mastics include such substances as filler, solvent and various additives. Roofing mastic is distinguished by the fact that it is able to create a coating resembling a film or membrane that will have all the properties of roll materials, but do not have seams. It is noteworthy that there are such types of mastics as bitumen-latex, which is used as an adhesive for laying roll materials both on the new roof and on the repaired old. The great advantage of bituminous mastics is undoubtedly the ability to paint them in any color. Dyes can be added during the already roofing works directly into the mass itself, but you can buy already colored in the store.
