Balcony Insulation

This will significantly improve the microclimate of your home: it will become warmer and much quieter.

How to Insulate a Balcony

Theoretically, there are two methods of balcony insulation: external and internal. However, since external insulation requires complex installation work and is practically impossible in multi-apartment buildings, it is better to choose the more accessible option: insulating from the inside.

The first step in protecting the balcony from rain and cold is installing 2-3 chamber double-glazed windows with a thickness of at least 32 mm. For modern new residents, this problem no longer exists: balconies and loggias in new buildings are already equipped with plastic windows.

After installing plastic windows, ensure the quality of the installation and proper sealing of all joints around the window frame, as well as that the mounting foam is protected from sunlight using sealant or trim. However, even with double-glazed windows, the balcony temperature only rises by 5 degrees in winter, which does not solve the problem of year-round use.

Internal Balcony Insulation

To make the balcony warm and dry, nearly all internal surfaces need insulation: the railing, ceiling, floor, and walls. It is crucial to choose insulation materials with the following properties: vapor, water, and air tightness, lightweight, low thermal conductivity, and environmental friendliness.

These requirements are fully met by popular insulation materials used by modern builders.

Penoplex, or extruded polystyrene foam, is a dense yet flexible board of various densities and thicknesses. This material is resistant to rot, durable, and can withstand temperature fluctuations from -50 to +70 degrees Celsius.
Rolled insulation made of foamed polyethylene coated with aluminum foil – a unique thermal insulator known for its lightness and flexibility.

Low thickness makes these materials indispensable, especially in small balcony spaces where every centimeter matters.

DIY Balcony Insulation: Step-by-Step Process

Insulation (polystyrene foam) must be attached to a flat surface, so walls must first be prepared: leveled with plaster, and any holes and cracks filled with foam.

Polystyrene foam boards can be fixed to all surfaces using anchors (plastic mushrooms). However, the most reliable method is to first glue the boards with special adhesive, and then secure them with anchors of appropriate length while the adhesive is still setting. Leave a 0.5 cm gap between boards. The thickness of the insulation is very important: it is recommended to use a 50 mm thick board for the first layer.

Fill the joints between panels with mounting foam, preferably using a specialized foam gun to avoid invisible air pockets. Trim excess foam with a knife.

Install vapor barrier: apply a 1 cm thick foiled film (Penoplex) as a second layer over all wall surfaces, with the foil side facing inward. Join the sheets tightly, with foil side facing the room. Seal all joints with special aluminum tape. Do not join the film at wall-ceiling, wall-floor, or corner junctions – this may create thermal bridges. Overall, use tape and foam to carefully seal all gaps during balcony insulation.

Next, install a framework (wooden or metal profile) to create an air gap (about 1.5 cm) – a thermos effect. Fix the framework to the wall using screws.

Finally, attach your chosen cladding: gypsum board, wooden siding, or wall panels. Before installing siding, treat it with a wood preservative, stain, or paint. Gypsum board must be troweled and primed before finishing. Wall panels require no additional finishing.

Insulating the Balcony Floor: Key Points

To ensure insulation fits tightly to the floor, first level it using a self-leveling cement-sand mix. Only then lay extruded polystyrene foam, just as on other surfaces.

To prevent condensation and mold formation, seal the gap between the insulation board and wall with waterproof tape. Then, apply a 5 cm thick concrete screed with 100 x 100 mm reinforcing mesh, followed by the final floor covering.

An excellent solution is installing a warm electric floor on the balcony. Although there is some hesitation about this method, it is actually very energy-efficient due to the limited heating area.

How to Heat a Balcony

If you do not install a warm floor, even with the best insulation, you will need additional heating sources during cold months. Important note: it is strictly forbidden to use central heating pipes for heating balconies!

The most convenient and commonly used heating solutions are electric heaters or even air conditioners, which provide warmth in winter and cooling in summer. Of course, equipment choice depends on your budget.

Insulating a balcony may seem complicated and labor-intensive. But the results of your effort and investment will exceed all expectations: you’ll gain a new functional space that can become an office, winter garden, or children’s playroom – entirely up to your preference. Moreover, reducing heat loss by 70% through balcony insulation will help save your household budget daily.