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How to Fit Secondary Glazing?


Installation Guide To Fit Secondary Glazing.

  1. Unpacking

KEEP THE FRAME UPRIGHT & carefully remove packaging from your window. Use a sharp blade to cut the plastic along its full length, corner to corner on the external [unseen] left, right and top edges. Flap the plastic away and lift the unit out. ENSURE if it’s HORIZONTAL SLIDING PANES that you have the top at the top otherwise the glazed panels may fall out. CAUTION.

See the Drawings shown under the various options in The Shop. There are only TWO options – FACE FIT to the existing window or REVEAL FIT to the plastered and decorated reveal at jambs, head and projecting cill.

  1. Tools

Remove the plastic once you’ve stood the unit at the installation point in order to avoid a slip/trip hazard. (Reuse as a dust sheet and don’t forget to recycle it!) Large TYPE VERTICAL SLIDERS may have a temporary strap across the width to avoid deflection in transport and fitting. LEAVE THIS IN PLACE until the last possible second! Try to have three screws in place or at least the packers or shims needed. Have all tools you will need. For plastered walls, you’ll need a drill and appropriate bits, plugs screws and screwdriver. For face fixing, you’ll need screws only. Both will need shims, wedges or packers at the periphery to level and plumb the window in position. You’ll need a Skeleton gun and Decorators CAULKING and adhesive to fit the trims. (UHU or Bostic is better than EVO-STICK because they allow a bit of movement). Have a lightweight nylon or rubber headed hammer to hand.

how to fit secondary double glazing
It is easier to fit secondary glazing using power tools.
  1. Fitting

TYPE HS(2 to 5) – Remove the sliding panels and put them safely aside. Check the frame fits satisfactorily in the opening, equalising the gap all the way around. CHECK you still have it the right way up for shuffle glazing the panels back in place if. Also, applies to the FIXED LIFTOUT.

FACE fitting, insert packers at the cill to ENSURE the unit is level. ALSO, ensure jambs are plumb. Packers/shims might also be needed when face fitting if the primary window is twisted. Keep your new window perpendicular.

REVEAL fitting, mark the screw positions, stand the frame down after equalising with packers/shims. Sticky tape the packers in place to stop them from falling off!!! Then drill and plug the holes into which the screws will fit; screw into place once having checked that the deeper channel is at the top for shuffling the panels in if HS. Ensure the panels’  bearings are at the bottom.

Replace the panes in the frame. You may want to use the rubber mallet to ensure the interlocking panes are fully engaging – once done, never again? 

Carefully select the trims, ensuring that you don’t cut down the wrong size allowed for the job as they are all supplied oversize for trimming to size. Cut the jamb trims [x 2] to size – full height. Glue them in place standing the nose of the trim flush up to the tip of the aluminium outer frame with the back edge of the trim to the surroundings. Cut the head and cill trims to size between the jamb trims {HINT} slightly chamfering the cut where it meets the jamb trims will look extra neat. The head trim may require tape to hold in place whilst your glue goes off.

VERTICAL SLIDING WINDOW FITTING is generally the same!  Remember to leave the transit strap in place for as long as possible! You DO NOT and CANNOT remove the panes to be stood aside. The WHOLE WINDOW is fitted as a single entity, followed by the trims, as above!

  1. Additional Noise Insulation (REVEAL FITTING only).

You will need (NOT supplied by Secondary Double Glazing) to apply acoustic caulking/sealant to the tolerance gap at the back of the SECONDARY WINDOW frame.  

Carefully measure the REVEAL linings at the periphery. Cut and prepare dense ACOUSTIC/FIBREBOARD to size. IMPORTANT; make sure the dimension between the new and old frames is reduced by a total of 3 – 4 mm that’s 1.5 to 2 mm between each edge of the board to the frames. Fix/glue the boards in place using spacers to ensure there are two gaps on either side of these liners and the installed frames – as this will assist in avoiding frequencies transmitting across the new and original windows. Remove the spacers when the adhesive has set, decorate to suit, without blocking the little gaps!