Timber Finseal - Seal for Windows and Doors

Timber Finseal – Kerf Fitting Draught Proofing Seal

Timber Finseal is a high-performance sliding and compression seal, designed specifically for timber windows and doors. It is engineered to press-fit securely into a kerf (groove) slot, offering a reliable and discreet draught-proofing solution for both new joinery and retrofit applications.

This seal is ideal for use in:

Double-hung sash windows

Timber sliding windows and doors

Timber entry doors with kerf grooves

Retrofit projects requiring improved thermal and acoustic insulation

Why choose Timber Finseal?

The seal features a dense polypropylene pile that compresses to fill gaps, while the integrated plastic fin running through the centre of the pile acts as an added barrier to air leakage, water ingress, dust, and noise. This makes Timber Finseal ideal for creating a continuous perimeter seal without compromising on window or door movement.

Whether you're restoring period sash windows or sealing new timber joinery, this product helps you achieve superior energy efficiency and occupant comfort without visible hardware or complicated installation.

Key Benefits:

Kerf-fit: Quick and easy installation with no adhesives or staples

Plastic fin enhances sealing performance against draughts and weather

Durable polypropylene pile resists wear, moisture, and UV degradation

Suitable for gaps between 3.0 mm – 6.5 mm

Ideal for sliding and compression-style windows and doors

Supplied in a continuous length based on your order – no joins or offcuts unless specified. For example, if you order 5 metres, you’ll receive one unbroken 5-metre length.

Technical Specifications:

Main Seal Material: Siliconised Polypropylene Pile

Centre Fin: Flexible plastic blade

Seal Operation: Hinged and Sliding Applications

Seal Fitting Type: Kerf Slot

Seal Gap Coverage: Min 3.0 mm / Max 6.5 mm

Kerf Slot Dimensions: 6 mm deep, 2.5 mm wide

Ensure kerf slot is clean and correctly sized before installation for best performance.

Installation Instructions – Timber Finseal (Kerf Fit)

Inspect the kerf slot: Ensure the groove is clean, dry, and free of dust, paint flakes, or debris. The kerf slot should be 6mm deep and 2.5mm wide for optimal fit.

Measure the frame: Measure each side of the door or window frame where the seal will be installed. Cut the Timber Finseal to match these lengths using scissors or a sharp utility blade.

Start with the top section: Gently press the Finseal into the kerf slot at the top of the frame, fin side facing outward toward the closing surface. Work slowly and evenly along the entire length.

Install the sides: Press the Finseal into the vertical kerf slots (jambs). Ensure the seal is flush and sits securely in the groove without stretching or bunching.

Check for gaps: Once installed, close the window or door to confirm consistent compression and no visible gaps. Adjust as needed to ensure a proper seal.

Final trim (if required): Trim any excess material for a clean, professional finish.

Tip: For best performance, avoid installing in extreme cold or heat. If the seal resists insertion, use a blunt tool (like a plastic card) to assist without damaging the pile.