Tips for installing windows in series 104

Tips for installing windows in series 104

Series 104 buildings are a common type of Soviet-era panel house with characteristic window openings: limited sill depth, thin reveals, and sometimes uneven edges. Proper installation of PVC windows in these apartments improves thermal and sound insulation, prevents drafts, and ensures long-term trouble-free operation.

Summary

• Accurate measurements are essential for a correct fit.
• Careful removal of the old window minimizes damage to reveals.
• Choose a profile and insulating glass unit suited to climate and noise levels.
• Maintain a 15–20 mm installation gap around the frame.
• Combine foam, internal vapor barrier and external breathable tape for sealing.
• Install a drip cap (window sill and external drip) with outward slope to shed water.

Preparation and measuring

1. Measure width and height in three places (top, middle, bottom) and check diagonals to detect twists and skew.
2. Measure recess depth, wall thickness and check the condition of surrounding reveals.
3. Order the window size allowing for installation gaps — usually 15–20 mm around the frame.

Removing the old window

• Remove trims and sill carefully.
• Detach the old frame to avoid damaging the concrete frame.
• Clean the opening from old foam and debris; check for cracks.

In series 104, reveals can be irregular and layered with remnants of old insulation — clean to the solid base before installing.

Preparing the opening and fixing points

• Level the surfaces with cement or repair mortar if needed.
• Mark anchor positions: typically 3–4 fixings per 1 m of window width.
• Use mounting plates or anchors depending on wall condition.

Choosing profile and insulating glass unit (IGU)

• A 5–6 chamber profile with a mounting width of 70–80 mm offers a good balance of strength and insulation.
• For noise-prone areas, choose a 32–44 mm IGU with two or three chambers.
• Pay attention to energy rating and warm edge spacer systems.

Installation gap, alignment and fixing

• Place the frame into the opening, level it using wedges and shims.
• Keep the installation gap uniform — recommended 15–20 mm.
• Fix through factory-reinforced zones with anchors or mounting plates.
• Check that sashes open and close smoothly and without binding.

Insulation and vapor barrier

• Fill the internal joint with vapor barrier tape or foam, then cover with a finishing trim.
• Use a breathable external tape or UV-resistant foam from the outside to prevent moisture ingress.
• The foam + tape combination creates an effective thermal and moisture barrier.

Sills, drip caps and reveals

• Install the external drip cap with a slope outward (10–15 mm per meter) for water runoff.
• Fit the internal sill with a slight inward slope (2–3 mm) away from the frame seam.
• Consider plasterboard reveals with added insulation or ready-made plastic reveals.

External sealing and finishing

• Seal external joints with silicone or butyl-based sealants to protect against water.
• If required, carry out façade finishing to hide joints and improve aesthetics.

Final checks and handover

• Test sash tightness, hardware operation and visual sealing quality.
• Check indoor temperature near the window during the first cold days.
• Provide the customer with a handover sheet and warranty documents.

Common mistakes

• Incorrect measurements leading to ill-fitting windows.
• Poor levelling resulting in sash misalignment.
• Inadequate external sealing causing moisture ingress.
• Using low-quality foam without proper tapes.

Maintenance tips

• Ventilate regularly to avoid condensation build-up.
• Lubricate hardware once or twice a year.
• Inspect seals and sealants periodically.

Frequently Asked Questions

Do I need to remove the internal sill when replacing an old window in a 104-series apartment?

Not always, but often the sill is replaced to correct angles and improve insulation. If the existing sill is in good condition, it can be reinstalled.

What installation gap is recommended?

A 15–20 mm gap around the frame is recommended. Larger gaps to compensate for uneven surfaces should be properly insulated afterwards.

How to protect the external joint from moisture?

Apply a breathable external tape and a suitable sealant, and ensure a properly installed external drip with a slope.

How long does a full installation take?

A complete job (removal, installation, insulation, and interior work) usually takes 1–3 days depending on complexity.

Can I install the window myself?

Yes, for simple openings but for complex cases and to preserve warranty it’s better to hire professionals.

We can prepare a measurement checklist and a recommended list of profiles and fittings for your specific window in a series 104 apartment upon request.