Every drop of water that seeps through the roofing can turn a garage from a reliable shelter for a car into dampness that destroys metal and provokes corrosion. The question of how to cover the roof of the garage from leaking, confronts property owners with frightening regularity, especially after the rainy season or snow melt. Ignoring minor defects often leads to large-scale destruction of load-bearing structures and damage to property, so surgical intervention is not only desirable, but critically important.
The modern construction market offers many solutions, from classical bitumen to high-tech polymer membranes. The choice of a specific material directly depends on the type of roof, the degree of damage, budget and climatic conditions of the region. Sealing of joints and restoration of the integrity of the coating require an individual approach, since there is no universal means that works equally well on a ruberoid, slate or metal.
In this article we will discuss in detail the main groups of waterproofing materials, their application technologies and nuances of surface preparation. You will learn why some compounds crack in the cold, while others lose elasticity under the scorching sun. Understanding the physical and chemical properties of materials will help you choose the option that will ensure dryness in the garage for many years without the need for annual reworking.
Bitumen mastics and primers: classics of waterproofing
Bitumen mastics remain the most popular and affordable way to eliminate leaks on flat and pitched roofs with a soft coating. The basis of such compositions is bitumen modified with polymers or rubber, which gives it increased elasticity and adhesion. Hot mastics require preheating to a liquid state, which allows the material to penetrate deeper into the pores of the old coating, creating a monolithic layer.
Cold mastics, in turn, are ready for use immediately after opening the bucket and mixing. They are most often produced on the basis of organic solvents or aqueous emulsion. To work with a garage roof, it is important to choose compositions with high heat resistance so that in the summer the coating does not float, forming bubbles. Before applying the main layer, the surface must be treated with a primer, which provides the base and improves adhesion.
⚠️ Warning: When working with hot bitumen, observe safety precautions - there is a risk of burns and ignition of the material. Work in protective clothing and gloves.
The effectiveness of bitumen waterproofing directly depends on the quality of base preparation. If there are swelling or detachment of the old ruberoid on the surface, applying mastic from above only preserves the problem, but will not solve it. Moisture trapped under the new layer will continue to destroy the structure. Therefore, mechanical cleaning and drying are mandatory stages before the start of work.
Liquid rubber: seamless coating of the new generation
Liquid rubber is an emulsion based on bitumen and latex, which, after polymerization, forms a strong, elastic and waterproof coating. The main advantage of this material is the lack of seams, which makes it an ideal solution for roofs with complex configuration or with a large number of adjoinments. Polymer-bitumen emulsion It is applied by spraying or brush, completely enveloping irregularities.
The material has excellent adhesion to metal, concrete, wood and old ruberoid. After drying, a film is formed, which stretches at temperature deformations of the base without breaking. This is especially true for regions with sharp temperature changes, when traditional bitumen coatings often crack. The service life of such a coating can reach 20-25 years, provided that it is applied correctly.
- 🌧️ High water resistance and resistance to ultraviolet light.
- 🔨 Possibility of application without dismantling the old coating.
- 🌡️ Maintaining elasticity over a wide range of temperatures.
Despite the high performance characteristics, liquid rubber requires careful surface preparation. The base should be dry and defatted. Applying the material in the rain or at high humidity is strictly prohibited, as this will disrupt the polymerization process and lead to detachment of the coating. For the garage, the best option will be a single-component composition that does not require the use of special equipment for mixing.
Before applying liquid rubber, close the ventilation holes and garage windows with polyethylene to avoid spraying into the room.
Roll materials: ruberoid, hydroisol and their analogues
When roof damage is extensive, local grease may not be effective and the entire roof must be covered with rolled materials. Traditional ruberoid It gradually fades into the past, giving way to more modern analogues based on fiberglass and polyester, such as hydroisol, glassisol or bicrost. These materials are much stronger and more durable.
The installation technology involves the fusing of the material on the base using a gas burner or gluing to a bitumen mastic. For garage roofs, a floatable method is most often used, which provides reliable sealing of joints. It is important to observe the overlapping of the canvases at least 10-15 cm to exclude the likelihood of water flowing under the coating.
When choosing a roll material, pay attention to the marking. The top layer should have a coarse-grained sprinkle that protects bitumen from solar radiation. The lower side is usually covered with a light-melting film, which signals the readiness of the material for melting. Using materials without protective sprinkling for the upper layer will lead to rapid destruction of the roof under the influence of the sun.
| Materials | Basis | Duration of service (years) | Difficulty of installation |
|---|---|---|---|
| ruberoid | cardboard | 5-7 | Low. |
| hydroisol | Fiberglass | 10-15 | Medium |
| Glassloisol | Glasswork | 15-20 | Tall. |
| Euroruberoid | polyester | 20-25 | Tall. |
Polyurethane and acrylic sealants for local repair
For sealing small cracks, seams between the plates or around the ventilation pipes, sealants are ideal. Polyurethane sealants They are characterized by high adhesion and elasticity, they perfectly hold on moist surfaces and are not afraid of moisture. Acrylic compounds are more environmentally friendly and suitable for interior work or dry surfaces, but are inferior to polyurethane in resistance to constant contact with water.
Silicone sealants are also widely used, but it is worth considering that acid silicones can cause corrosion of metals. For roofing work, it is better to choose neutral silicones or specialized roof sealants. They retain elasticity for decades and do not crack under the influence of ultraviolet light.
Before applying the sealant, the surface must be cleaned of dirt, oil and exfoliating particles. For better grip, it is recommended to treat the edges of the crack with a primer. The sealant is applied with a small excess, since during polymerization it can decrease slightly in volume. You can smooth the seam with a spatula dipped in a soapy solution.
⚠️ Note: Do not use oil-based sealants to repair the roof – they will not dry completely and will melt in the sun, soiling the roof.
Surface Preparation: A Key Stage of Success
The quality of repair of the garage roof depends on the correct surface preparation by 80%. Even the most expensive and high-quality material will not be kept on a dusty, wet or greasy base. The first thing the roof needs to be thoroughly cleaned of debris, leaves and dirt. For this, you can use broomsticks, brushes or even a high-pressure wash, if the roof design allows.
After cleaning, the surface should dry completely. The presence of moisture under the waterproofing layer will lead to boiling of bitumen when heated or the formation of bubbles when applying cold mastics. If there are bloating of the old coating on the surface, they must be carefully opened cross-opened, moisture removed and dried.
☑️ Checklist for roof preparation
Degreasing is another important step, especially if there are traces of oil or bitumen stains on the roof that have lost their properties. For this, you can use gasoline or special solvents. After degreasing, a primer is applied, which binds the residual dust and creates a sticky layer to improve the adhesion of the main material.
How do you check the moisture of the concrete?
Take a piece of plastic film size of 1×1 meter and glue it tightly with tape around the perimeter to the surface of the roof. Leave it for 24 hours. If condensation has formed under the film or the concrete has darkened, drying must be continued.
Technology of applying waterproofing with their own hands
The process of applying waterproofing varies depending on the material chosen, but the general principles remain unchanged. Work should be carried out in dry, warm weather at an air temperature not lower than +5 ° C. Windy weather is also undesirable, especially when working with liquid compounds or fusing roll materials.
When using mastics, it is important to apply them uniformly, avoiding skips. Usually 2-3 layers are required, each of which is applied after drying the previous one. The directions of application of the layers should be perpendicular to each other to create reliable reinforcement. Pay special attention to the places adjacent to the walls, pipes and drains - it is recommended to use a reinforcement net.
If you have chosen the floatable method, warm the material evenly, preventing bitumen from burning out. A sign of proper warming is the flow of a bitumen roller from under the edge of the canvas. The movement of the burner should be smooth, zigzag. After laying the material should cool naturally, walking on it at this time is prohibited.
The main secret of durability is not to skimp on the primer and do not break the temperature regime when applying materials.
Prevention of leaks and care of roofing
To the question of "what to cover the roof" did not rise annually, it is necessary to regularly maintain the roofing. At least twice a year, in spring and autumn, you should inspect the roof. During the inspection, foliage, branches and other debris are removed, which can trap moisture and destroy the coating.
Keep an eye on the state of the drainage system. Clogged drains lead to stagnation of water on a flat roof, which creates an excess load and increases the risk of leaks. Also check the condition of the sealant around the ventilation pipes and antennas – these are the places that first begin to pass water.
If you notice minor damage or cracks, fix them immediately. Repairing a small site is cheap and takes a little time, while delaying it can lead to the need for a complete roof replacement. Regular maintenance extends the life of any waterproofing material.
Can I apply a new waterproofing over the old one?
Yes, in many cases this is possible, especially when using liquid rubber or bitumen mastics. However, the old coating should be firmly coupled to the base, do not have swelling and putrefactive damage. If the old ruberoid cracked and peels off, it is better to remove it or use it as a basis for laying a new roll layer with the mandatory use of a primer.
At what temperature can the roof be repaired?
The optimum temperature for most bitumen and polymeric materials is from +5°C to +25°C. At lower temperatures, materials become viscous and fall poorly, and at too high - can grasp or drain too quickly. In winter, repairs are possible only with emergency fast-hardening compounds, but this is a temporary measure.
How long does the bitumen mastic dry?
The drying time depends on the type of mastic, layer thickness and weather conditions. Usually one layer dries from 12 to 24 hours. Full polymerization and strength can take up to 7 days. Before applying the next layer, be sure to wait for the previous one to dry completely.
What is the best way to close the joint between the roof and the wall?
For sealing of adjoining it is best to use polyurethane sealants in combination with reinforcing tape or a special apron of galvanized steel. Simple smearing with bitumen often gives a crack at the junction site due to different coefficients of expansion of wall and roof materials.