Selection Of Roofing Materials

2023 Author: Douglas Hoggarth | [email protected]. Last modified: 2023-08-25 05:40

• How much does the roof covering weigh?
• How long will the roofing material last?
• Roofing cost

• Characteristics of the two most popular types of "light" roof

  • Metal tile
  • Bituminous shingles (soft roof, flexible shingles)
• How not to be mistaken in choosing roofing materials

The roof covering must effectively resist any precipitation, be rustproof, strong and durable, attractive in appearance and inexpensive - such is the desire of any homeowner faced with the problem of choosing roofing materials. The abundance of roofing coatings in the construction markets will easily baffle you - each seller praises his product, making unflattering remarks in the direction of competitors' products. How not to miscalculate and make a conscious and correct choice of material for roofing - the article is devoted to this very issue.

How much does the roof covering weigh?

Traditionally, natural tiles are considered the best roof covering - it was they who were used by the builders of the Middle Ages, forming the roofs of palaces and castles, while the poor made do with straw. Of course, ceramic tiles look solid and durable, but they weigh a lot. And its weight - 40-60 kg / m ² will seriously affect both the roof ceilings and the walls, the foundation of the building - the weight of the ceramic roof should be taken into account even at the design stage of the house.

"Light" roofing, the weight of which does not exceed 5-7 kg / m ², looks more preferable for any roof slabs. In this group of roofing materials, metal tiles and soft roofs are especially distinguished, as well as bituminous tiles.

How long will the roofing material last?

In fact, the deadlines called by the sellers, following the “guaranteed life” of a particular roofing, are not entirely correct - different climatic zones, different territories have their own atmospheric and other environmental conditions. First of all, humidity and temperature drops play a role - types of roofs, the elements of which are porous in their structure, will quickly collapse along with freezing-thawing cycles of moisture filling the pores. Also, the ultraviolet radiation of the Sun is a real scourge of roofing - the colors fade, the structure of bitumen and ceramic tiles, not protected from ultraviolet radiation, loses its plasticity and cracks.

The protection of soft (bituminous) tiles from ultraviolet radiation is based on mineral chips applied to the front side of the outer surface - in case of partial or complete loss, it must be reapplied or the roof must be painted. When choosing ceramic tiles as roofing, please note that it must be glazed!

Of the roofing coverings of the middle price range in Russian climatic zones, metal tiles will last the longest. But the service life of inexpensive galvanized steel and euro slate will be the shortest.

Roofing cost

In addition to the obvious price differences between different types of roofing, even the cost of one type of roofing varies greatly. There are several reasons for this:

• thickness of the material from which this coating is made;
• the type of coating that protects against atmospheric agents, ultraviolet radiation, etc.;
• Colour;
• form of execution;
• the remoteness of the outlet selling roofing from the manufacturer;
• fluctuations in exchange rates.

The manufacturer's trademark has a special influence on the cost - often it is she who acts as the guarantor of the quality of the roofing.

The average price for the most popular roofing materials is as follows:

• glazed tiles - 1,400 rubles / m ²;
• metal tile - 250 rubles / m ²;
• bituminous tiles - 400 rubles / m ²;
• euro slate - 370 rubles / sheet (1.9 m ²);
• profiled galvanizing - 220 rubles / lin. m (width 1,000 mm).

A classic mistake made by the buyer when choosing a roof covering is the assessment of the ratio of "material price" to "cost of installation work." Meanwhile, the final cost of the roof will be much higher - it will include additional elements and costs for a number of additional works, which cannot be done without. When studying proposals for roofing, you need to take into account the cost of the weir system, cornices and ridge, end and end strips, waterproofing materials and work on their installation. Also, the total estimate will include transportation and a variety of consumables.

Example: the parameters of the roof, which must be covered, are, say, 15x15 m. To cover a pitched roof of this size, in addition to the roofing material, 15 m of a drain gutter will be required. If the roof is gable, you will need to buy 15 m of the ridge; for the weir, you will need already 30 m of the gutter. A hipped roof of this size will require 45 m of the ridge and 60 m of the gutter. As you can see from the example, the more complex the shape of the roof, the more expensive the roof is for it.

Characteristics of the two most popular types of "light" roof

Metal tile

This modern type of roofing has replaced classic shingles in the same way as siding - wall cladding with wooden clapboard. The special appeal of metal tiles is that they look very much like ceramic tiles.

However, this roof loses to its ceramic ancestor in a number of characteristics: low noise insulation, high thermal conductivity, and a tendency to form condensation on its inner surface. The solution to the first two problems will be a layer of insulation, say, mineral wool. And the problem with condensation will be solved by a vapor barrier layer - a PVC film.

Like any other metal roof, metal tiles accumulate atmospheric and static electricity - a lightning arrestor is required, despite the anti-static passivation layer declared by the manufacturer in the metal tile coating.

A high-quality metal tile resembles a layer cake - a steel sheet with a thickness of 0.45 mm to 0.8 mm, sequentially coated on both sides with zinc, a passivation layer, primer, polymer and varnish.

The polymer coating, which determines the color and chemical resistance to aggressive atmospheric influences, is different and it depends on the type of polymer how long a given brand of metal tile will last in a particular climatic zone.

The main types of polymer coatings for metal tiles:

• polyester is a popular and inexpensive polymer for covering metal roofing tiles. The glossy coating made of this polymer is well resistant to atmospheric influences, ultrasonic resistant. It is applied with a layer of 25 microns;
• a subtype of polyester with a matte surface - matte polyester. Looks good on the roof and has all the qualities of a glossy polyester. It is applied with a layer of 35 microns;
• plastisol is a durable and highly corrosion-resistant coating. Its 200 micron layer protects the steel sheet well from damage, but it does not withstand heating temperatures over 60 ° C, therefore, it is not suitable for areas with high solar activity;
• polyurethane (pural) - especially suitable for areas of difficult ecology and for roofing in coastal areas. Resistant to fading, successfully protects metal from chemical corrosion. It is applied with a layer of 50 microns;
• PVDF (PVDF) - the most resistant to ultraviolet radiation, retains color for many years. Its layer of 27 microns is highly resistant to mechanical damage and aggressive atmospheric influences. In terms of quality characteristics, metal tiles with PVDF polymer coating are the most durable.

How does a low-quality metal tile turn out - its manufacturers save on a layer of passivation and a primer without applying them. As a result, the roofing covering for 5 years completely loses its polymer layer and rusts, forcing the owners to incur unplanned costs for replacing the roof.

Bituminous shingles (soft roof, flexible shingles)

Lightweight and durable roofing material that looks like ceramic tiles. Bituminous shingles are flat sheets containing 3-4 cut-out plates (shingles) of rectangular, trapezoidal, triangular, oval or wavy shape. This is a roof - regardless of seasonal changes in temperature, its softness and flexibility are provided by modifier additives, they also provide resistance to heating by the sun's rays - bitumen melts at +80 oC, bitumen tiles can withstand over +120 oC).

The shingles are based on fiberglass, the first outer and inner layers are modified bitumen, the outer face layer is basalt or mineral chips. The front layer on the inner (back) side is rubber-bitumen covered with pvc-film at self-adhesive tiles or sand and a bitumen-polymer strip for fixing the tile sheet on the roof, followed by gluing to heated bitumen or special glue.

Among the positive qualities of shingles: minimal waste, it does not need additional heat and sound insulation, does not rot, does not allow moisture to pass through - the principle of a carpeted roof, an absolute dielectric, does not support combustion, practically does not fade, it is resistant to strong gusts of wind, etc. … In addition, a reinforced roof structure is not required for a flexible roof, because the weight of bituminous tiles rarely exceeds 12 kg / m ². And finally, it is not difficult to repair it - just replacing damaged sheets without completely dismantling the entire roof.

Probably the only drawback of bituminous tiles is the need for a solid base, that is, it is necessary to fix OSB boards or plywood sheets on the crate first, only then the flexible tiles are installed. Compared to a lattice base for metal tiles, such a base for roofing will cost more.

How not to be mistaken in choosing roofing materials

When choosing a metal tile, be sure to find out the number of layers covering it, make sure of their number personally by examining the cut on a fragment of a metal tile of this type, which the seller must have. It will be correct to choose the type of roofing material with a thicker metal layer. Well-known manufacturers of this type of roofing put a mark on the edge of the front side, from where you can find out the country of origin and the company that made this roofing.

The simplest way to find out the strength of a metal tile - whether the metal thickness is really from 0.5 mm and more - is as follows: put a sheet of metal tile on a flat floor and step with one foot on its edge. If the wave bend bends, the metal is thin and not suitable for overlapping the roof.

Visit the seller's warehouse: if the sheets of metal tiles are stacked one on top of the other without dividing wooden bars between them, refuse the purchase. After all, if the seller does not know how to properly store this roofing, his words about guarantees and product quality are dubious.

When choosing a brand of bituminous shingles, pay attention to the weight of a square meter of coverage - the larger it is, the better the quality of the roofing material itself, i.e. the layers forming it are thicker. Ask the seller what bitumen modifier is used in it - it is better to choose a tile with a SBS modifier, since it is more resistant to temperature extremes.

The seller must give a detailed answer about the guarantees for the roofing material - the conditions for guaranteed waterproofing and resistance of colors to ultraviolet light. Find out the delivery time, whether this type of flexible roofing is constantly present in the seller's warehouse, or is it delivered only on order.

Regardless of the type of roofing chosen, it is important that the entire purchased roof square is from the same batch (the date of manufacture must also be the same). The fact is that the color scheme of roofing materials from different batches may differ slightly and upon completion of the roof overlap, the difference in shades will be noticeable.

Before making a purchase decision, try to find houses whose roofs were covered with the material you are interested in several years ago, ideally at least 5. Visually inspect such roofs, check with the homeowner for the brand and manufacturer of the roofing.