28mm Triple Glazed Unit - Energy A+ Rated

Cleaning & Maintenance

Your 28mm triple glazed unit requires minimal ongoing maintenance to deliver decades of reliable performance. Regular cleaning keeps glass looking its best and helps identify any issues early.

Routine Cleaning

Clean both faces of the sealed unit using warm water with a small amount of washing-up liquid and a soft, lint-free cloth or sponge. Avoid abrasive cleaners, scouring pads, or razor blades, which can damage coatings and seals. Rinse thoroughly with clean water and dry with a chamois or microfibre cloth to prevent water spots.

Seal & Spacer Bar Inspection

Inspect the perimeter seal every 6–12 months. Look for cracking, peeling, or gaps in the secondary sealant (typically black polysulphide or silicone). If you notice internal condensation between the panes, this indicates seal failure — contact Pane Relief for a warranty assessment.

Frame & Drainage

Keep drainage slots in the window frame clear of debris. Blocked drainage channels allow water to pool against the sealed unit edge, which accelerates seal degradation. A pipe cleaner or compressed air clears most blockages.

External Condensation

With a U-value of 0.9 W/m²K, external condensation is likely during cold, clear nights — particularly in autumn and spring. This is a sign the triple glazing is insulating effectively. The condensation clears naturally as the outer pane warms with daylight. No action is needed.

Installation Guide

Correct installation is critical to the long-term performance of your 28mm triple glazed unit. These guidelines cover standard rebated-frame glazing — always refer to the frame manufacturer's instructions for system-specific requirements.

Preparation

Inspect the unit on delivery. Check for chips, cracks, or seal damage before removing protective film. Verify dimensions match the frame rebate with 3–5mm clearance on all sides. Ensure the frame rebate is clean, dry, and free from old putty or sealant residue.

Setting Blocks & Packers

Place two setting blocks (minimum 50mm wide) at the quarter points of the bottom rail — approximately 50mm from each corner. Use 5mm flat packers for side and top clearance. Setting blocks must be load-bearing nylon or HDPE, not timber, which can swell and crack the glass.

Glazing & Sealing

Apply a continuous bead of neutral-cure silicone sealant to the back of the glazing bead before pressing into position. Do not use acid-cure silicone, which attacks the spacer bar sealant. Ensure the glazing bead is fully seated with no gaps — water ingress behind the bead is the most common cause of premature seal failure.

Drainage

Verify that frame drainage slots (minimum two per unit, positioned at the lowest point of the rebate) are clear and functional. The sealed unit must never sit in standing water.

28mm-Specific Notes

At 28mm, this triple unit fits most rebates designed for standard double glazing (typically 24–28mm). Verify the rebate depth accommodates 28mm plus setting block and sealant clearance. For frames designed for 24mm units, a glazing adaptor or deeper glazing bead may be required — consult the frame manufacturer.

Weight: a 28mm triple unit is approximately 30% heavier than an equivalent double-glazed unit. For larger panes (over 1.5m²), use a glazing trolley and suction lifter. Two-person lift recommended for units exceeding 1m × 1m.

10-Year Manufacturer's Warranty

Every 28mm triple glazed unit from Pane Relief is backed by our comprehensive 10-year manufacturer's warranty, covering seal integrity, gas retention, and coating performance. Our BS EN 1279-certified manufacturing process ensures each unit meets the highest quality standards.

The warranty covers: internal condensation caused by seal failure, visible coating degradation, and argon or krypton gas leakage beyond acceptable levels. Normal wear, external condensation (a sign the unit is working efficiently), and damage from incorrect installation or handling are excluded.

To make a claim, contact our Bristol team with your order reference and date of purchase. We aim to inspect and resolve all warranty claims within 14 working days. For installations carried out by FENSA-registered installers, we can process claims directly — no third-party paperwork required.