DIY sandwich panel garage

If you need a prefabricated, inexpensive and warm garage – pay attention to the sandwich panel. This material is lightweight, which allows you to make a lightweight foundation. In addition, it comes immediately with paintwork inside and out, so finishing work is also not needed. It is assembled on a metal, less often wooden, frame in a few days (subject to the availability of a ready foundation). So a sandwich panel garage is a good option. 

What are sandwich panels made of?

Sandwich panels are a three-layer structure, which consists of two outer layers of rigid material and insulation located between them.

Rigid material – most often it is galvanized steel. And it is this material that is usually used if a garage is built from sandwich panels.. And they are also made of sheet polymers, wood-polymer composites (WPC), chipboard materials (OSB, plywood, GVL, GSP, etc.).

When used as an outer shell of galvanized steel, it is covered with a protective and decorative coating. Most often it is one of the tinted polymers. The most common are polyester and pural (pural is better in performance, stronger and more durable). The polymer film increases the service life of the material, makes it insensitive to aggressive media. The coating color of galvanized metal sandwich panels is selected according to the RR and RAL tables and in total can have more than 240 shades.

Insulation in sandwich panels is used differently:

• Basalt wool. It has good characteristics, but is afraid of getting wet (loses its thermal insulation properties), and absorbs water in the form of liquid and vapor. When freezing in a wet state, after thawing it can simply crumble. To eliminate this drawback, it is necessary to ensure the sealing of the sections, which is problematic when building a garage.
• Glass wool. He is not afraid of moisture, but it is very problematic to work with it – full protective clothing is necessary – thick clothes, a hat, gloves, high shoes, plus a respirator and goggles. The material is very caustic, and the smallest particles penetrate everywhere. It has good characteristics, but is rarely used.
• Styrofoam. Lightweight material with a honeycomb structure. It is not afraid of moisture, has very good thermal insulation properties, and belongs to low-combustible materials. Its disadvantages are crushing under loads (compensated by the rigidity of the outer shell), insects and small animals love to gnaw it. Good option, but not the best.
• Polyurethane foam. Excellent thermal insulation material, the characteristics of which do not depend on humidity. It does not rot, bacteria and fungi do not multiply in it, insects and rodents do not like it. The disadvantage is the high price, respectively, and sandwich panels with such filling are more expensive.

If possible, it is better to build a garage from sandwich panels with polyurethane foam insulation. Although it will turn out more expensive, there will be no problems even if the humidity rises.

By type of profile, sandwich panels are wall and roof. They differ in profile shape (corrugation height) and dimensions:

• Wall are:
  • width from 1000 to 1200 mm:
  • thickness from 60 to 260 mm.
• Roofing:
  • width – 1000-1600 mm;
  • thickness 20-260 mm.

Sheets of sandwich panels are connected to each other with locks of various shapes. Walls usually have a tongue-and-groove lock, while roofing ones have an “overlap” lock.

Wall panels can be with smooth or profiled walls. Profiles can be ordinary (corrugation of different heights/widths) or decorative.

Mounting and fastening

A garage made of sandwich panels belongs to the category of frame buildings. Under them, a metal frame is usually assembled (from profiled pipes), to which panels are attached with self-tapping screws. In order for it to provide the required bearing capacity, the minimum wall thickness of the pipe must be 1,5 mm. For a small garage, racks can be made from a pipe 150 * 50 mm, for more solid ones up to 150 * 150 mm.

Such a large width of the pipes is explained by the peculiarities of the installation of sandwich panels – they are attached to the frame, stepping back from the edge of 50 mm. So it turns out that when connecting two panels, the distance between the two screws will be 100 mm. With a 150 mm post width, 25 mm remains for greater fastening strength.

The roof truss system of the garage from sandwich panels is assembled as usual – from a bar or cooked from the same profiles as the frame. The minimum slope of a roof covered with this material is 10°.

A frame for a small garage, for one or two cars without superstructures, can be made from a dry beam with a section of 150 * 150 mm. It is pre-treated with bio-protective compounds, then with flame retardants.

Fasten the sandwich panels with special self-tapping screws (self-tapping screws). They are made of hardened steel, covered with a layer of zinc. This fastener has a diameter of 5,5 mm and an octagonal head. Sometimes, rubber sealing washers are used to ensure tightness. When installing them, make sure that the washer is pressed tightly against the material, but the screw should not deform the outer layer.

During installation, the screws are placed strictly perpendicular to the surface, avoiding deviations, otherwise there is a high probability that the metal will be damaged and water will flow inside the panel, which will cause its destruction.

The minimum fastener length depends on the panel thickness and is shown in the table below. In general, the self-tapping screw should be screwed into the frame by at least 35 mm. That is, its minimum length is the thickness of the panel, plus 35 mm.

The number of self-tapping screws per square meter of area depends on the type of building and wind loads in the region. When building a garage from sandwich panels in Moscow and the region or in St. Petersburg, it is enough to screw them on the sides of the panel in increments of 300-400 mm.

When mounting on a metal frame, a rubber sealing tape is glued to the posts and crossbars. On one of its sides there is a sticky layer protected by a strip of paper. Before installation, the paper is removed, the tape is glued to the frame racks.

Methods for mounting wall panels

Installation of wall sandwich panels can be vertical and horizontal. A frame is made for each of them, taking into account the features of fastening in each case. The distance between the posts is equal to the width of the selected type of materials. Only the first posts from the corner have a smaller distance (by 150 mm if 150*50 mm or 150*150 mm posts are used).

When laying horizontally, the first sheet is installed directly on the plinth. For better thermal insulation, foam or polystyrene foam can be placed under the panels. The lock must be turned so that the grooves are outside. So water will not flow into the junction.

With vertical installation, sheathing with wall sandwich panels starts from one of the corners. The direction of the lock is chosen arbitrarily. For better thermal insulation, foam or polystyrene foam can also be placed under the panel.

Regardless of the type of laying, before fixing the sheet, it is necessary to check whether it is correctly positioned. Take the level and check the verticality or horizontality of the installation. Only after that install the fasteners.

During installation, one of the drawbacks of buildings made of sandwich panels can be eliminated – the lack of insulation in the seams, which is why the rooms are blown through and quickly dry out. To improve the thermal performance, a mounting tape, butyl rubber cord or thin insulation is laid in the joint. Sometimes, to ensure tightness, the joint is coated with sealant. This is especially true when constructing a roof, but it will not hurt for the walls of the garage. During the joining of the plates, it is important to ensure that the sheets are tightly adjacent to each other, but the heat-insulating material cannot be crushed.

After installation, the corners and side joints of the sheets are laid with insulation and covered with decorative corners or strips. The color is chosen to match the base coat or a contrasting color.

Installation of the roof systems

The roof of sandwich panels is made after wall cladding. Few of the private garages are more than 12 meters long, so it is better to lay the roof panels in whole sheets along the overhang. This will avoid creating vertical seams that are difficult to seal.

If the truss system is assembled from metal, a rubber seal is glued to the beams and girders, then installation begins. When laying, the lock is turned with a spike up – towards the ridge. Before joining, the junction of the sheets is coated with silicone sealant. This ensures good sealing of the roof.

When installing roof sandwich panels, longer self-tapping screws are needed – more wind loads (see table below).

There are also mounting features:

• First, you can fix the sheet with just two screws. After laying the entire surface, install the remaining screws.
• The fastener is installed at the top of the wave, starting from the top, moving down.
• On the plane of the roof, the installation step is 500 mm.
• Self-tapping screws are placed along the overhang in increments of 250 mm.
• After fixing all the sheets, an overlapping wave is additionally attracted. For this, self-tapping screws with a grooved gasket with a diameter of 4,8 mm and a length of 28 mm are used. The installation step is at least 500 mm.
  

After the installation of roofing sandwich panels is completed, they begin to finish the overhangs and the ridge. They are sewn up with shaped elements made of galvanized metal with the appropriate color. When installing, it is important to ensure tightness, for which the elements are installed with an overlap of 80-100 mm. Additionally, the joints are coated with a sealant for outdoor use.

All additional elements are fastened with self-tapping screws with a diameter of 4,8 mm and the required length. Be sure to use a rubber seal.

Node diagrams

Not everything can be explained in words, more often a graphic image conveys more information. The main components that may come in handy when you build your garage from sandwich panels are collected in this section. Everything is detailed and signed.

Rules for storage and operation

Sandwich panels should be stored on a flat area. If there is none, use bars or other similar material, the surface of which will create a flat surface. You can put the bars with a step of 1,5-2 meta, but you need to make sure that they are in the same horizontal plane.

The service life of the material depends on the integrity of the polymer coating. Therefore, during storage and during operation, try not to damage the surface. When scratches appear, they are degreased and painted over with repair compounds.

When a garage is built from sandwich panels, they have to be cut in places. If the thermal insulation is mineral (basalt) wool, this should be done in a respirator. If the insulation is glass wool, then closed clothing, protective gloves and goggles are also needed.

Metal can be cut with metal shears (manual or electric). The use of an angle grinder (grinder) with a disc is prohibited: when cutting, the metal in the cut area is very hot, the zinc coating evaporates. As a result, after a short period of time, the cut begins to rust.

Sandwich panel garage: dimensions and projects

Finding ready-made garage projects from any material is quite difficult. They do not always order a full-fledged project even for building a house, but there is nothing to say about outbuildings. However, when planning a garage made of sandwich panels, you inevitably wonder about the optimal dimensions. If we talk about the minimum, then they consider that the width of the garage should be 1 meter more than the width of the car, and the length should be 1,5 meters. This is if you plan to install at least some equipment. With such dimensions, it can be placed against the back wall. If there is no equipment, it is enough to add 1 meter to the length of the car.

If you need a viewing hole, it is made shifting a little closer to one of the walls, and usually to the left. Space is left on this side so that the doors can be opened without problems in the garage. To make it more convenient upon arrival, boards of 40-50 mm thickness are laid on the pit. They easily withstand any passenger car.

If there are two cars, the distance between them should not be less than 60 cm, and for comfort it is better to leave the same meter.