Fixing and buying guide
VELUX Centre-Pivot Roof Windows White Painted 94x55cm GGL PK25 2070
Who this product is for
This window suits homeowners and builders installing skylights in pitched-roof properties across the UK. The PK25 size is standard for most domestic roof conversions and loft extensions. Centre-pivot windows are preferred where you need easy cleaning access from inside and reliable manual operation without motorisation. The white painted finish integrates with most interior schemes and provides a clean, maintenance-friendly surface.
- Domestic loft conversions and roof extensions
- Properties with pitched roofs at 15–55 degree angles
- Rooms requiring good natural light and manual ventilation control
- Installations where motorised or remote operation is not required
Sizing and compatibility
The PK25 dimension (94x55cm) is a standard VELUX size that fits between rafters spaced 550mm apart, with typical rough opening requirements of approximately 980x600mm. Confirm your roof pitch falls within the 15–55 degree range and measure your rafter spacing before ordering. This model is compatible with standard VELUX flashing kits and accessories designed for PK25 windows. Check that your roof structure can support the weight and that you have adequate headroom below the installation point.
- Fits rafter spacings of 550mm
- Roof pitch range: 15–55 degrees
- Rough opening approximately 980x600mm
- Compatible with PK25 flashing and accessory range
Pack contents and pre-installation checks
Your VELUX GGL PK25 2070 arrives as a complete window unit with frame, sash, hardware, and glazing. Before installation, inspect for transport damage, confirm the model number matches your order, and check that all moving parts operate smoothly. Ensure your roof structure is sound, rafters are level and properly spaced, and any existing roof covering is removed from the installation area. Have your flashing kit, insulation materials, and weatherproofing products ready before you begin.
- Inspect the unit for damage on arrival
- Verify model number GGL PK25 2070 matches your order
- Test centre-pivot operation before fixing
- Confirm roof structure is sound and rafters are level
- Prepare flashing kit and weatherproofing materials in advance
Fixing and installation overview
Centre-pivot windows are secured to the roof structure using the integral frame brackets and fixing points. The sash rotates inward from the centre, allowing full access for cleaning and maintenance. Follow VELUX installation instructions precisely, ensuring the frame is level and square before final fixing. Proper flashing installation is critical for weatherproofing; use the appropriate PK25 flashing kit for your roof covering type. Allow adequate ventilation around the frame and seal all gaps with approved materials to prevent water ingress.
- Use integral frame brackets and fixing points as specified
- Ensure frame is level and square before final fixing
- Install flashing kit appropriate to your roof covering
- Seal all gaps with approved weatherproofing materials
- Test operation and weathertightness before completion