Construction of a full-fledged box for one vehicle often becomes an economically infeasible solution when all you need to do is protect car from precipitation, hail and scorching sun. Owners of summer cottages and country houses are looking for a compromise between a permanent structure and a simple shed, paying attention to lightweight metal structures, popularly called “garages for cars.” This approach allows you to save up to 60% of the budget that would have been spent on erecting walls made of brick or aerated concrete, while maintaining the basic functions of protecting the body.
Creating such a shelter with your own hands requires accurate calculation of the loads on the frame, especially if you plan to use it in winter, taking into account the snow cap. The design is rigid metal skeleton, sheathed with profiled sheet or polycarbonate, which is installed on a prepared base. The absence of main walls simplifies ventilation, which is critical for preventing metal corrosion, but requires the correct choice of roof angle for effective drainage.
Before you start purchasing materials, you need to decide on the dimensions of the future structure in order to car comfortably fit inside with room to open doors and move a person around it. Standard sizes usually vary between 3 meters wide and 6 meters long, which corresponds to the average class of cars. It is important to understand that even a lightweight structure requires a reliable foundation, since the windage of the roof in a strong wind can lead to the displacement or overturning of the entire structure.
Selecting the type of structure and materials for the frame
The first step in implementing the “do-it-yourself garage for cars” project is choosing the technology for assembling the supporting frame. The most popular and affordable option remains the use of a square or rectangular profile pipe. Profile pipe provides excellent structural rigidity with relatively low weight, which makes it possible to install elements even without the use of heavy lifting equipment. For racks, a section of 80x80 mm or 100x100 mm is usually chosen, and for roof trusses and purlins, a pipe of 40x40 mm or 60x40 mm is sufficient.
An alternative to a welded metal frame can be prefabricated structures made of LSTK (light steel thin-walled structures) or even reinforced wooden beams treated with fire and bioprotection. However, metal remains the leader in durability and fire safety. When choosing between welding and bolting, it is worth considering your skills: a weld is more reliable, but requires skill, while bolted connections allow you to disassemble the garage if necessary, although they require regular checking of the tightness of the fasteners.
⚠️ Attention: When choosing the wall thickness of a profile pipe, do not skimp on metal. For racks with a height of more than 2.5 meters, the minimum wall thickness should be 3-4 mm, otherwise the structure may deform under wind load.
Protecting metal from corrosion is key to the longevity of your structure. After welding, all seams must be cleaned and primed, and then a minimum of two coats of weather-resistant enamel must be applied. Modern alkyd or acrylic paints for exterior use can last 10-15 years without renewal, maintaining an aesthetic appearance metal garage.
- 🔹 Rectangular profile pipe - the optimal balance of price and strength for racks and trusses.
- 🔹 Corner 50x50 mm - suitable for creating additional stiffeners and connections.
- 🔹 Bolts of strength class 8.8 - necessary for components where welding is impossible or undesirable.
- 🔹 Antiseptic impregnations are required if you combine metal with wooden sheathing elements.
Calculation of the amount of metal
For a 3x6 meter garage you will need approximately 180-200 linear meters of profile pipe with a cross section of 40x40 mm for trusses and purlins, and about 40 meters of 80x80 mm pipe for vertical posts. Always take a 10% margin for scraps and waste when cutting.
Foundation preparation and foundation work
The quality of the foundation directly affects the stability of the structure, especially if we are talking about a lightweight structure with a large roof windage. For a “car garage,” a columnar or pile-screw foundation is most often chosen, since they are cheaper and faster to install than a solid concrete slab. Screw piles can be hand-tightened in one day and are immediately ready to absorb loads, making them an ideal solution for heaving soils.
If you plan to use the garage year-round and store tools or spare parts inside, it makes sense to pour a concrete screed. To do this, the fertile layer of soil is removed along the perimeter, backfilled with sand and crushed stone, waterproofing and reinforcing mesh are laid. Concrete grade M200-M250 will provide a strong and level platform that will not generate dust and will make it easy to clean the room.
| Foundation type | Installation time | Cost (relative) | Applicability |
|---|---|---|---|
| Screw piles | 1 day | Average | Any soil, slope |
| Columnar (concrete) | 7-14 days | Low | Dense soils |
| Tape shallow | 14-21 days | High | Heaving soils |
| Monolithic slab | 21-28 days | Very high | Garage workshop |
It is important to provide for the organization of drainage around the perimeter of the foundation. Even if there are no walls, water flowing from the roof should not wash away the foundation. It is enough to make a slight slope of the soil from the center or lay a drainage ditch filled with crushed stone. This will prevent puddles from forming under by car and will increase the comfort of using the garage in rainy weather.
☑️ Preparing the base
Manufacturing and installation of roof trusses
The roof is the most critical element of the “car garage” design, experiencing maximum loads from snow and wind. It is better to make trusses on the ground, assembling triangular structures from a profile pipe, which are then lifted and welded to the posts. The optimal slope angle for central Russia is 20-30 degrees: at a smaller angle, snow will accumulate, and at a larger angle, the wind load will increase.
To connect the truss elements, use sheet metal gussets 4-6 mm thick. This simplifies welding work and increases the joint area, making the assembly more reliable. The distance between the trusses is usually 1-1.5 meters, depending on the length of the span and the selected roofing material. The heavier the roof covering, the more often they should stand load-bearing trusses.
⚠️ Attention: Never skimp on the number of points for attaching trusses to racks. A minimum of two welding or bolting points per truss leg is required to ensure spatial rigidity.
After installing the trusses, purlins are installed on them - horizontal pipes onto which the sheathing or roofing material will be attached. The pitch of the purlins depends on the type of roof: for corrugated sheets 0.5-0.7 meters is enough, for heavier materials the pitch is reduced. All metal elements of the roof also require careful anti-corrosion treatment, since they are in direct contact with the atmosphere.
- 🔹 The triangular shape of the truss is the most stable and easiest to calculate.
- 🔹 Metal scarves - strengthen pipe joints.
- 🔹 Ridge run - connects the trusses into a single system and serves as a support for the top of the roof.
- 🔹 Wind connections are diagonal elements that prevent the frame from swaying.
Choosing roofing and cladding
The choice of material for the roof of a “car garage” depends on the budget and noise insulation requirements. The most popular option is corrugated sheet (profiled sheet) with polymer coating. It is lightweight, inexpensive, quick to install and available in a wide range of colors. For a garage, the optimal wave height is 20-35 mm (grades C20, C21, NS35), which provides sufficient rigidity.
Polycarbonate (cellular or monolithic) is a modern alternative to metal. Cellular polycarbonate transmits light, which allows you to save on lighting during the day, and looks great. However, it has a high coefficient of thermal expansion, so during installation it is necessary to use special thermal washers and leave gaps in the joints, otherwise the sheets may “lead” or burst.
Metal tiles look more aesthetically pleasing than corrugated sheets and better imitate natural tiles, but require more complex installation and mandatory sound insulation, otherwise rain will turn the garage into a drum. To fasten all types of metal sheets, special roofing screws with EPDM sealant are used, which prevent leaks at the drilling points.
Use colored screws to match the roof. Galvanized screws will rust over time and leave unsightly streaks on the roof, which will ruin the appearance of your garage for cars.
Roof ends and gables also need protection. You can use wind strips made of the same material as the roof, or cover the ends with cellular polycarbonate to protect from side rain and snow. This is especially true if the garage is located in an open, drafty place.
Space organization and additional functions
Although a “car garage” is often perceived as a temporary or seasonal solution, proper organization of space turns it into a full-fledged functional place. Even without walls, you can provide areas for storing seasonal rubber, tools or gardening equipment. To do this, racks or hanging storage systems mounted on frame posts are installed along one of the long sides.
Lighting is an important aspect of comfort. Conducting electricity allows you to use the garage at night. LED spotlights mounted on roof trusses will provide bright and economical illumination of the work area. Wiring should be carried out in corrugated pipes fixed to metal structures, observing all fire safety standards.
If you plan to use the garage in winter, you should think about a gate or at least thick curtains made of PVC fabric. They will protect against snowstorms and reduce heat loss if a heater is installed inside. Soft windows or sheer curtains allow you to retain natural light, but create a barrier to cold wind.
- 🔹 Corner racks - cheap and reliable for storing spare parts.
- 🔹 Hooks on the ceiling - for storing skis, boards or long items.
- 🔹 220V sockets - necessary to connect a compressor or charger.
- 🔹 Ventilation holes - prevent condensation even in an open garage.
Typical mistakes during construction and their elimination
Self-construction is often accompanied by errors that can shorten the life of the structure. One of the most common is not deepening the supports enough or using too thin metal for the posts. This leads to the fact that under the influence of the wind the garage begins to “walk”, and over time it warps. Strengthening the structure with diagonal braces at the installation stage it can correct the situation, but it is better to immediately lay down the necessary safety margin.
Another mistake is the wrong choice of fasteners for the roof. Using ordinary metal screws without a rubber washer guarantees leaks in the first rain. Also, expansion gaps are often forgotten when using polycarbonate, which leads to destruction of the sheets. Carefully studying the instructions for the materials and using specialized fasteners will eliminate these problems.
⚠️ Attention: Do not weld roofing sheets directly to the frame! Thermal deformation of the metal will lead to separation of weld points and corrosion. Use only mechanical fasteners (screws, bolts).
Lack of processing of pipe ends after cutting is another “silent killer” of metal. Moisture quickly penetrates the pipe cavity, causing corrosion from the inside out. Be sure to weld the ends or cover them with plastic plugs after painting.
The main secret of durability is not the thickness of the metal, but the quality of the anti-corrosion treatment and the correct geometry of the frame. A crooked garage made from a thick pipe will fall apart faster than a smooth one made from a thin but well-assembled one.
Do you need a permit to build such a garage?
In most cases, light metal structures without a foundation (or on screw piles) with an area of up to 25-50 sq.m. are considered non-permanent buildings and do not require a building permit. However, legislation may change, and local regulations (SNT, dacha cooperatives) may have their limitations. Before starting work, it is recommended to clarify this issue with the local administration or board.
What is the service life of a garage made of corrugated pipe?
With high-quality anti-corrosion treatment and regular maintenance (touching up scratches every 3-5 years), the metal frame will last 20-30 years or more. A roof made of corrugated sheets with a high-quality polymer coating (polyester, pural) retains its properties for 15-25 years. Polycarbonate lasts less - about 10-15 years, after which it may become cloudy or lose strength.
Is it possible to insulate such a garage?
It is possible to insulate a “garage for cars”, but this is economically and technically feasible only if there are walls. Insulating one roof in an open structure is ineffective. If you are planning insulation, it is better to immediately consider the option of building a full-fledged shell garage with sandwich panels or wall sheathing with insulation.
How to protect your garage from burglary?
An open structure is vulnerable. For protection, use high-quality padlocks on the gates (if any), install motion sensors with GSM alarms. An effective method is to weld additional hinges or pins to install removable metal curtains or bars at night, turning the open space into an enclosed box.