Insulating the Balcony Yourself
But these are additional, golden square meters of your living space. Have you thought about it, but don’t know how to do it? It’s not as complicated as it seems—just need to know how, and the best option is to follow the experience of those who have already done it.
Where to Start?
Insulating a balcony is a construction project, and before building, you need a plan. Of course, you can visit a design office and order a project, but you can also do it yourself. First, decide what result you expect from the renovation. Maybe you want to remove a partition wall to increase room area. But that’s a major structural change and requires registration. Also, it’s uncertain how well you can insulate the balcony yourself. Recommendations are helpful, but much depends on your skills and talent—so it’s wiser to focus on balcony insulation and turn it into a separate, additional room.
How to Insulate
It’s best to remove all extra fencing structures, keeping only the partitions. Cover the facade with aerated concrete blocks or ceramic bricks.
Although, if you have a solid reinforced concrete railing, you can keep it. The advantage of bricks is high strength and excellent appearance. Why are aerated concrete blocks recommended?
- Relatively low weight—important since the masonry is on a balcony and shouldn’t bear excessive loads.
- Low thermal conductivity—our goal is to insulate the balcony.
To determine the height of the masonry, you must first decide on glazing.
Glazing the Balcony
Decide on balcony glazing before you start dismantling everything. If you plan to install PVC windows, remember they are quite heavy. Some older balconies may not support the load, so it’s better to consult a specialist. In case of doubt about balcony strength, choose lighter glazing.
If you’re confident in your balcony’s strength, go for well-tested PVC profiles with double-glazed windows and standard hinged sashes. You’ll also need expansion profiles for better insulation. Otherwise, part of the glazing will be covered by the structure during insulation and finishing.
Sealing Gaps and Sealing
After glazing, seal all unavoidable gaps and perform sealing. You’ll need: construction foam, mastic, and sealants. Consider polyurethane sealants like: Germaflex, Rubberflex, Germabutyl, Emfimastika, etc. To prevent sealant from leaking to lower neighbors, seal joints with foamed polyethylene or at least pieces of polystyrene. Finally, fill remaining gaps with construction foam.
Insulation
Now it’s time to begin what you’ve been preparing for—insulating the balcony. Again, you face a choice: high-quality insulation that takes more space, or a more compact, cost-effective option with lower thermal performance.
This recommended approach is ideal for connecting the balcony to the room, as insufficient insulation increases the risk of condensation. Condensation reduces thermal resistance, and your effort and investment will be wasted. Also, in a humid environment, mold may appear—leading to negative results. To prevent this, apply a thicker insulation layer on walls, ceiling, and floor, or use insulation materials with superior energy-saving properties.
Experts recommend extruded polystyrene: FIBRAN ECO (ФИБРАН ЭКО), URSA XPS, TECHNOPLEX, STYROFOAM, PENOPLAX, etc. You can choose cheaper types like PSB-S35, PSB-S50, etc., but you’ll lose quality and durability for lower cost.
A different type of insulation material is mineral wool: ISOVER, Knauf, Rockwool, etc. The key difference is that mineral wool is installed between wooden battens.
Extruded polystyrene is fixed directly onto concrete slabs and masonry walls. What exactly is extruded polystyrene? It’s a type of foam board, sold in sheets measuring 120x60 cm, with thickness from 2 to 10 cm.
The required thickness is achieved by stacking multiple layers. Sheets are secured using adhesive or anchors. Choose adhesive that does not degrade polystyrene—e.g., ATLAS STOPTER K-20, Krepes PPS, Ceresit CT 85, Emfikol 225, Izolemf 3104/11, etc.
When using anchors, select those with wide heads—so-called mushroom anchors. (See photo 2.) Anchor sizes depend on insulation thickness. In practice, most people combine both methods—adhesive and anchors.
Start installation from the floor to prevent gaps. If the floor has major unevenness or isn’t level, perform leveling first.
Polystyrene sheets are cut with a sharp knife or regular saw. Lay them in a staggered pattern. Joints are sealed with non-toluene-containing construction foam (toluene damages extruded polystyrene). Toluene is often added to winter or universal foams. For efficient foam application, use a foam gun—this saves material and eases work. Similarly, apply insulation to walls and ceiling.
Over the polystyrene, lay a layer of foil-faced expanded polyethylene for vapor barrier. This material, 3–10 mm thick, comes in rolls 90–120 cm wide. (See photo 3.) Attach with adhesive, end-to-end. Seal joints with construction tape. Avoid joints at corners. After completion, balcony insulation is done. Next step: finishing—but that’s another article.
