Frequently asked questions about window installation

Summary

• What to know before ordering and installing windows
• How to prepare your apartment for installation
• The importance of accurate measurement and old-frame removal
• How to fill and protect the installation gap
• Installation timeframes, warranties and acceptance
• Tips for care and ventilation after installation

Introduction

Window installation is a critical stage of renovation or replacement: proper installation affects thermal performance, durability and absence of drafts. This guide answers common customer questions before, during and after installation.

Before installation: preparation and measuring

What should you prepare?

• Clear the work area: remove curtains, move furniture away, take plants off the windowsill. Keep the sill free of items.
• Inform neighbors if noisy work is expected.
• Ensure exterior access if the installation requires work from the outside.

Who performs the measurement and why is it important?

Measurements should be done by an experienced company technician. Accurate measuring ensures the correct window design, mounting brackets, drainage and sill sizes. A wrong measurement leads to rework and extra costs.

Removing the old frame and preparing the opening

Do you need to remove the old frame entirely?

Often the old frame is removed completely to inspect the opening and jamb condition. In some cases only sashes can be replaced, but that reduces energy efficiency. Removal affects estimate and time.

What about the sill and external drip?

The sill is usually removed and, if necessary, replaced. The external drip flashing is installed after the window to ensure the correct slope for water runoff.

Installation: rules and materials

What fills the installation gap?

The gap is typically sealed with polyurethane foam followed by vapor and moisture barriers. A recommended three-layer scheme: inner vapor-permeable gap, main insulating foam layer, and outer waterproof layer (membrane or tape).

What is the normal gap width?

An optimal gap is about 10–20 mm on the interior finishing side and up to 30–50 mm on the exterior depending on the profile and insulation requirements. Too narrow or too wide gaps complicate the work.

Are extra fasteners needed?

Yes. Large units require metal plates, anchor brackets and special anchors. The correct choice of fasteners depends on wall material (concrete, brick, panel).

Work acceptance and warranties

How to accept the job?

• Check level and alignment; there should be no visible gaps.
• Open and close sashes — operation should be smooth.
• Inspect seals, drip flashing, sill and jambs.
• Ask the installers for certificates of materials and warranty documents.

What warranties exist?

Warranties are separate for profile, fittings and installation. Typically profiles and hardware have factory warranties of 5–10 years, installation 1–3 years. Check the contract terms.

Care and use after installation

• Remove excess foam and protective film after 24–48 hours.
• Avoid strong drafts for 2–3 weeks while foam cures.
• Regularly lubricate hardware and clean glass with mild cleaners.
• Ensure adequate ventilation, especially in new buildings.

Important: don’t hermetically seal the joint outside without an inner vapor-permeable layer — condensation may form.

Frequently Asked Questions (FAQ)

1. How long does installation take?

A single window block typically takes 2–6 hours to install. With removal, finishing of jambs and drip, the work may take 1–2 days.

2. Can windows be installed in winter?

Yes, but winter installations are more complex: special winter foam and methods are used. Professional companies perform year-round installation with adapted materials and temporary heaters if necessary.

3. What if I feel drafts after installation?

First check hardware adjustment and sash pressure. If it’s a gap issue, contact installers to check joint sealing.

4. How much does installation cost?

Cost depends on window size, profile type, opening complexity, and region. Exact pricing requires a site measurement.

5. Should jambs be insulated?

Yes. Properly insulated jambs prevent thermal bridges and mold. Use breathable insulating materials and moisture-resistant finishes.

6. Can I place the sill immediately after installation?

The sill is installed on the installation day or after the foam has cured (usually 24–48 hours). Avoid heavy loads on the sill until full curing.

Conclusion

Good installation combines precise measurement, professional removal, correct materials and a careful acceptance process. Work with reputable specialists, require a contract and clear warranty conditions. Following simple preparation and care rules will extend the life of your windows and ensure comfort.