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TRC Sash Window Renovation with High Performance Draught Proofing

Sash window restoration service which transforms decayed and damaged windows, upgrading them and protecting them for the future. Sash window insulation not only improves thermal performance, it also protects the window.

Features and benefits:

  • Solves draughts and rattling.
  • Reduces dirt, dust and rain ingress.
  • Smoother, easier window operation.
  • Hidden, rebated seals, not surface mounted.
  • Tested for water permeability, air tightness and wind resistance.
  • Installed by expert window restorers.

General information


All bare timber surfaces are primed with one coat of preservative primer

Uniclass 2015

Pr_30_59_98_96 Wood window unitsPrimary


L10/10 Wood windows

L10/210 Wood windows

Specification data - Wood window units

Product Reference

TRC Sash Window Renovation with High Performance Draught Proofing

Frame colour/ finish


Insert requirement from RAL classic range.


Insert requirement from TRC stain range.

White - RAL 9016





Not required

Double glazed

Ultra-slim and efficient.

Perimeter spacer bars

Insert requirement.




Insert requirements, consult with manufacturer for information.

Colour/ Finish


Polished chrome

Satin chrome

Special order

Insert requirements, consult with manufacturer for information.

Standard product features


All bare timber surfaces are primed with one coat of preservative primer.

Sash Window Removal System:

  • Makes cleaning and maintenance easy.
  • Sashes simply unclip from sash cords.
  • Discreet design, not visible in normal use.
  • Sashes are removed from inside the building.
  • TRC’s own design.
  • Installed by our expert window restorers.

Timber repair:

Decayed and damaged timber is gently prised out from windows, frames and sills, retaining as much of the original wood as possible. Where decay is severe, sections of timber is replaced with new joinery work to closely match the original. Whole cills or cill fronts can be replaced seamlessly to match the original window profile.

The remaining timber is treated with a multi-stage epoxy resin repair system called Repair Care Smooth. Using specialist tools, the surface of the repair is carefully smoothed to match the shape of the original timber, so that it blends seamlessly. Finally, the window is stained or painted as required.

Draught proofing:

Draftfix system which typically uses a weather pile with a central fin, fixed into a plastic carrier which is rebated into the casement. The weather pile prevents dust and dirt ingress, and the central fin contributes to air tightness. All the seals are rebated into the casement, which means no unsightly, protruding, face-fixed seals.

Draught proofing is applied to three places around a sash window; the staff bead, on the bottom rail of the lower sash, also known as the sash stop. The meeting rail, where the two sashes overlap across the centre of the window and the parting bead, at the top of the upper sash, in the centre of the frame. Verified to BS 6375-1.

Perimeter sealing system performance:

  • Air permeability (to BS EN 12207): 600 Pa (Class 3).
  • Water tightness (to BS EN 12208): Result: 250 Pa (Class 6A).
  • Resistance to wind load test pressure, and frame deflection (to BS EN 12210: 2000 Pa (Class A5).
  • Weather tightness (to BS 6375-1): 2000.
  • Acoustic: Increases performance of a window by 6–10 dB (A).

Product Options


Comprehensive collection of sash window furniture available in elegant, classic styles to suit all eras. Pulleys, handles, fasteners, lifts and stops available in a wide range of finishes, bespoke designs are available.

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