UPVC Window Installation Guide
The 70mm UPVC window system we are using is designed with the installer in mind. Crammed with great features, this system is part of the only window range to incorporate strength and energy efficiency into one lead-free profile. The multi-chamber design prevents the transfer of warm air to the outside, keeping more heat inside the building and achieving an A+ Window energy rating as standard.
Before The Installation Begins
Firstly, when measuring and surveying a window, make sure that you allow the required expansion gap around the perimeter of the frame. Care must be taken to check that the structure is secure and that it is safe to remove the existing window. For the purpose of this video, the surveyors have allowed the correct tolerance of 5mm all around. It is good practice to double-check sizes and styles when you arrive on site.
Before you begin to remove the existing window, check the thickness of the plaster reveal both internally as well as externally, as well as carry out a pre-installation risk assessment to identify and reduce the risk of potential hazards.
Remove The Existing Window
To minimize damage to decorations and the reveal, break the bond between the frame and the plaster, by running a sharp blade around the perimeter of the old window, both internally and externally. To make it easier to handle, remove as much of the glazing as possible. You can unscrew and remove any of the sashes, reducing the overall weight of the final frame to remove.
Prepare The Area
Once the window has been removed you’ll need to clean off any old sealant and debris from around the opening, removing any loose mortar. Now you’ll need to prepare the external sill. To fit it to the new frame, the sill can be either straight cut to the width of the window frame, or in some cases it can be rebated to form a horn around the external face of the brickwork, to give a neat finish.
Fit the sill end caps using superglue and activator to secure them. It is good practice to run a bead of silicone along the sill’s upstand prior to fixing it to the window, to prevent the possibility of water blowing through the joint. Secure the sill to the bottom of the window frame using appropriate PVC screws making sure that they do not pierce the internal glazing rebate. In order to prevent moisture from tracking along the sill and into the brickwork it’s necessary to seal the ends of the sill and frame assembly.
Install The Window
Take care when placing the new frame into the opening. To make sure that it sits central, use packers all around the frame checking its level, square and plumb, and that the 5mm expansion gap is maintained. Double check that the frame is plumb and level before drilling fixing holes for the sides of the frame, approximately 150mm from the top and bottom corners and at 600mm centres in between. Remember that because these windows do not contain steel reinforcement, it isn’t necessary to apply as much force when drilling. Take care not to over tighten the fixings.
There should be a minimum of two fixings per side, and that it’s important that the packers bridge the full width of the frame to prevent distortion. Fix the sides of the frame to the wall using nylon frame anchors, self-tapping masonry screws or other suitable fixings to match the aperture and surrounds.
In order to prevent deflection in windy conditions, you will need to directly fix the top and bottom of the frame over 1200mm in width, in accordance with industry codes of practice. Use silicone around the holes that are drilled through the bottom of the frame before inserting the screws, to prevent water entering the reinforcing area inside of the frame. For a neat finish, break off the excess length of the packers with a chisel.
Fit The Glass
Any brick dust or debris will need to be cleaned from the frame and surrounding areas before starting to fit the glazing. Ensure that you use the correct glazing platforms and that they are fitted around opening before you begin glazing the frame. This will ensure the window maintains its support, keeping the glass square in the frame and allowing water to pass into the drainage slots.
These glazing platforms clip easily into place and don’t slide out. It’s important to note that installers using different glazing platforms may experience issues as the glass may not slide into place easily and could potentially get stuck. Note that where opening casements are hinged from the side, they will need to be toed and heeled. This means that the glass is packed at diagonally opposing corners at the bottom of the hinge side and at the top of the handle side, holding the casement square.
We can now install the glass, ensuring a tight fit against the glazing platforms. Additional glazing packers can be used to lift the sash to the required height. To ensure ease of use and allow visual alignment and an equal seal around the frame, it is worth noting that the toe and healing process transfers the weight of the glass to the bottom hinges and allows the top hinge to hold the sash in place. Make sure that the unit is pushed right back into the glazing seal using a glazing shovel if needed.
Fit The Beads
Once the glass is in place, fit the beads. To help locate the beads spray glass cleaner around the edges, which helps the beads move across the glass easier and always start with the smaller bead. First, locate the back of the bead into the groove and then use a nylon mallet to tap it into place, tapping on the edge where the bead meets the edge of the frame.
After all the panes are fitted, clean the frame and glass to remove dust or grit before sealing the frame to the internal wall, keeping the room well ventilated during the use of cleaning agents. To allow for redecoration we recommend the use of acrylic sealant or decorators caulk.
That completes all of the internal work, now make sure that all dust and grit is removed from the external surfaces, then apply a strip of masking tape to the perimeter of the frame and apply a smooth bead of silicone sealant between the frame and the brickwork. Carefully remove the masking tape before the sealant sets for a neat, clean finish.
Remember it’s important to also seal the underside of the external sill. Clean the debris away from the working area, and check that the correct compression is achieved on the window. Make sure that any adjustments are made, and then you can show the customer the correct way to operate the windows.