Nova Secondary Glazing

General Information:

Secondary windows will be manufactured as a factory glazed product.

The standard options will come complete with cover strips, catches and hinges where required.

All catches are silver in colour and can be supplied non-locking or Allen Key Locking. Black Catches are available on RAL Colours.

Colour Options:

Silver Anodised.

All standard RAL colours are available (subject to surcharge).


Black U-Channel Gasket.

Glazing Thickness:

4mm Glazing
6mm Glazing
6.4mm Laminated

Glass Types:

6.4 Laminated glass for additional safety.
Pilkington K™ glass for increased thermal performance.
Stadip Silence Acoustic glass for enhanced noise reduction.
Obscure glass with 5 levels of privacy.

Toughened Safety Glass:

Passes BS 12600-2002 Safety Glass for Use in Buildings.

Technical Information:

All sliding options will be supplied as standard configuration unless clearly stated on the order form.

All frames will be supplied glazed with 4mm single glass as standard.

Foam can be supplied in 5m rolls.

All price list grids include 4mm annealed single glass as standard however we strongly recommend the use of toughened glass.

When panels exceed the recommended maximum sizes for 4mm glass it may be necessary to change the glass specification to achieve the panel size you require.

Glass panels should not exceed 1000mm x 1500mm when using 4mm float glass.

Lift out panels should not exceed 1.5m2 (at this size they weigh approx. 20kg). It is recommended that all panels that can be removed i.e. lift-outs and horizontal sliding panels are glazed with either 4mm Tuff or 6.4mm laminated safety glass.

Horizontal sliding panels should not exceed 2400mm high.

Maximum overall frame width available is 4700mm. (4 & 5 pane only).

All panel heights and widths are measured from the edge of frame to the centre of the mullion.

Vertical sliders should not exceed 1500mm wide x 2400mm high.

The horizontal and vertical slider outer frame is 50mm front to back and with a low 35mm sight line all round.

Vertical sliders up to 1000mm wide will be supplied with one Fitch catch. Wider vertical sliders will have two Fitch catches 250mm from each end.

General Notes and Surveying:

All secondary windows are designed to either face fix or reveal fix.

It is recommended that when measuring the window reveals, several width and height measurements should be taken. 6mm or less is then deducted from the smallest measurement to determine the window size.

If the aperture is not square this deduction may have to be amended accordingly.

For windows that are face fixed against the primary window or timber subframes we can supply self adhesive foam which is designed to insert into the outer frame channel creating a compressed seal. This is optional on our order forms.


There are various glazing options available for our secondary system up to a maximum of 6.4mm (this would include the use of Stadip Silence glass).

Generally speaking the windows would be set 100mm from the primary glass pane for optimum sound reduction.

It is possible to fix the secondary frames directly to the primary window bearing in mind this will not always provide the optimum glass to glass cavity and the primary window hardware may foul the operation of the secondary window.

When setting back 100mm in the reveal several fixing methods can be used, horizontal sliders can be fixed directly to the reveal, through the sides of the frame.

(Note: Do not drill into the bottom track as the roller wheels travel in the track section).

The bottom section can either be adhered to the window board or face fixed into a baton as described below.

For face fixing: Lift Out, Fixed, and Vertical Sliders 100mm from the primary window it will be necessary to provide timber batons (usually 2 x 1 inch planed timber,) around all four reveal sides allowing the secondary to be screwed directly to the batons.

Vertical Sliders:

Our vertical sliding secondary is manufactured and delivered as a glazed up item. Carefully remove the plastic cover trims from the outer frame using a flat blade or Stanley knife and determine the position of your screw fixings (Not Supplied).

Pencil mark the aluminium channel usually 100mm from each corner and centred at approximately 300mm centres thereafter face drill the outer frame suitable for your screw fixings.

The frame should be lifted into the reveal, set plumb and level at the desired position from the primary window and care taken that the aluminium sections are correctly packed and supported at the critical positions.

It is advisable to initially wedge and pack the window in place whilst it is squared and levelled.

Once the window is set correctly and secured with two or three screws initially it may be advisable to carefully operate one panel checking again that it runs square within its outer frame before final fix is carried out. 

Please note - our vertical sliding panels do not tilt in for cleaning purposes.

NB: Face fixing vertical sliders directly to the primary window will restrict cleaning from the inside.

Horizontal Sliders:

All horizontal sliding panels should be removed whilst preparing and drilling the outerframe. Once packed and aligned, two or three screws down each side (excluding the bottom track) should be used to secure.

Be aware that in the case of horizontal sliders the track must be flat and level, if it is tipped even slightly the Fitch catches may not align correctly.

The sliding panels can be lifted into place by dropping the wheels into the track first and ensuring the panel is the correct way up with the nylon wheel blocks at the bottom.

It is important to make sure the panel is securely pressed down onto the wheel carriers and can slide freely to ensure the outer frame is fitted plumb and square.

Hinged Casements:

Care should be taken when surveying that allowance is made in the width for hinges and catch which is a total of 50mm.


These are face fixed and size permitting can be installed with the panels in place which helps when checking they are square etc.

Fully Fixed:

These are face fixed and designed as a permanent panel. Care should be taken to make sure the glass is clean before fixing to the primary window frame.

It is strongly recommended that foam tape is used for an optimum seal.

All Products

It is usual after installing the Secondary window to fill gaps between the outer frame and the reveal.

Dependant on the size of the gaps and once the plastic screw cover trim has been fitted they can either be covered with D moulds (not supplied) or silicone/caulk sealed using the correct sealant.

Acoustic mastic can be sourced from your sealant supplier.
Nova Secondary Glazing