• {{item}}

Send to us

Fitting uPVC Windows

Fitting uPVC Windows

Here’s why fitting uPVC windows is best left to us

Achieve comfort, security and effortless style.

You’ll be surprised how affordable fitting uPVC windows can be, especially when installed by Boyland Windows. Comfort, security and effortless style – uPVC is a simple choice that offers high energy efficiency. Designed so that it’s strong, robust and secure, there is a wide range of styles and options to choose from that are suitable for all properties.


At Boyland Windows, we take every opportunity to show our customers the beautiful range of uPVC windows they can order and install. 

However, we have written this guide to give people who have never fitted a window before insight into the process of fitting uPVC windows. The most important step is ensuring that the new window will fit within the brickwork opening left by the old window. This can only be achieved by accurate measurements and good calculations – something our team are all too familiar with.


What’s involved when fitting uPVC windows?

An impressive number of benefits for your home.

Unplasticised Polyvinyl Chloride – otherwise known as uPVC – is an easily maintained building material. Commonly used as a substitute for painted wood and timber frames, it is mostly used for newly built window sills and frames. Fitting uPVC windows will bring an impressive number of benefits for your home.

  • Affordable prices
  • Durable and long-lasting materials
  • Easy to clean and low maintenance design
  • Energy-efficient double glazed and triple glazed options
  • Fantastic range of styles and design options
  • High levels of security and safety
  • Smooth opening and closing


Here’s what our team utilise when it comes to fitting uPVC windows:

Chisel | Electric drill | Flat pry bar | Glazing platforms | Glazing shovel | Level | Measuring tape | Pencil | Philips head bit | Plastic packers | Putty knife | PVC screws | Silicone caulk | Soft-headed mallet | Super glue | Utility knife | Work gloves




Here’s how we might go about fitting uPVC windows

We’ll takes you through our process – from start to finish.

Step 1 of fitting uPVC windows

Preparation. Preparation. Preparation.

When measuring the windows, ensure you’re leaving a required expansion gap of 5mm either side of the frame. This will give you room to square the frame in the opening. Care must be taken to ensure the structure is secure and that it is safe to remove the existing window. Before any installation work is started, be sure to check the size, style and condition of the new uPVC windows against the entire sight.


Step 2 of fitting uPVC windows

Remove the existing window.

To make it as easy as possible to handle, remove as much of the old frame and glazing as possible. This will reduce the overall weight of the frame. Break the bond between the frame and the wall. We run a sharp blade around the edge of the frame. When ready, we remove the fixings around the frame. Using a flat pry bar, we loosen and wedge the window away from the wall – taking care not to damage the surrounding area.


Step 3 of fitting uPVC windows

Prepare the window area.

Once the window is removed, we need to clear off any sealant or debris left around the opening. We also remove any loose mortar and recheck the measurements.


Step 4 of fitting uPVC windows

Prepare and fit the windowsill.

Fit the seal-on caps to the sill with superglue. Check whether it’s to be straight cut to the width of the uPVC window frame or – in some cases – install the former horn around the external brick as more of a feature.

We run a beam of silicon on the edge and fill up an expanse before fixing it to the window. This is to prevent the possibility of water flowing through the joint and moisture from splashing on the sill and into the brickwork.

The next stage is to remove the corner protectors and protection tape from the brand new uPVC frame. Then we secure the sill to the bottom of the window frame using appropriate uPVC screws. Where required, we attach any frame extending on another bead of silicon both ends up the head and film to ensure it’s watertight.



Step 5 of fitting uPVC windows

Fitting uPVC windows.

Having ensured that the combination of the uPVC window and windowsill will fit the intended space, we carefully place the new uPVC frame into the opening. Making sure it’s central, we use packers to align the frame – checking its level, square the 10mm expansion gap is maintained. Double check the frame is level before drilling holes in the sides of the frame.

Fixing should be 150mm from the top and bottom corners and approximately 600mm centres. In between, these pre-drill the frame at the required spacing before fixing them in place with suitable fixings.

Taking care not to over tighten them, ensure the packers are used adjacent to each fixing. It’s important that these packers cover the full width of the frame to prevent distortion when tightening the fixings. Additional fixings will be required to the top and bottom of the frames that are over 600mm in width. Take a look into the pre-drilled hole through the bottom of the frame before inserting the spacers. This prevents water entering the frame onto the inserted protection. Scoop seal with more silicone to create that watertight seal.



Step 6 of fitting uPVC windows

Glass installation.

What you now face is the task of removing the glazing trim bands. They come out quite easily, but can just as easily be damaged. Also, be careful not to mix them up as they need to go back in the same position later on. Any dirt or dust needs to be cleaned from the frame before the installation of the glass can begin. Insert the bridging package around the opening. Failure to use these will mean water will not drain out of the frame which could lead to unit failure.

Now to install the glass against the bridging packet. You’ll notice that there is a gap between the edge of the glass and the bridging packers. You will need to push packers in these gaps, ensuring the unit remains square and parallel until it is firmly held in position. Once you are happy with the position of the unit and the packers, use silicone to secure the packers in place to prevent any from ruining.

Once in place, you can use special lubricating spray to help you reinsert the glazing bands you removed earlier (ensuring they go back in the right place). Always start with the shorter bands. With a little squirt, you can then place the back of the band into the groove and use a rubber mallet to tap it into place. Toughening on the edge where the band meets the frame. Once you get one end of the trim in, the rest follows quite easily. Now fitted, clean the glass and the uPVC frames to remove any dust before sealing the frame to the internal wall or cutting fit any internal trims. That completes all the internal work



The smaller glazing bands are quite a bit harder than the longer ones because there’s less room and less flexibility. For this reason, it’s best to use the smaller ones first.



Step 7 of fitting uPVC windows

Finishing the installation.

For a neat finish, break off any excess length or the package with the chisel before removing all protective tape from the outside of the screen ensure all dust is removed from the external surfaces and the frame is clean. Run masking tape along the edge of the frame to help create a neat finish before running a smooth band of sealant between the uPVC frame and the brickwork. Check the operation of the window and make any adjustments needed before cleaning down the working area


Get in contact so we can start fitting uPVC windows

First impressions are everything. Make yours count with Boyland Windows.

If we were to sum up Boyland Windows, we would say we are a solution provider for all your home improvement needs. We work with many product partners to supply you with the best possible option to use with your GOV Double Glazing Grant.


We cover:

Ashley – Barton on Sea – Boscombe – Bournemouth – Brockenhurst – Burley – Burton – Christchurch – Dorset – Ferndown – Hampshire – Highcliffe – Hurn – Lymington – Lyndhurst – Milford on Sea – Mudeford – The New Forest – New Milton – Poole – Ringwood – Southbourne – West Parley – Wimborne – Winton

At Boyland Windows, our friendly advisors can point you in the right direction for the best windows and doors. Have any further questions? We’re open Monday to Friday, 8 am – 4:30 pm.

Please feel free to get in touch by calling 01202 499499 or use our contact form.


  • Which logo
  • Energy Saving Trust
  • FENSA logo
  • Home Improvement Protection logo
  • Trust Mark logo
  • Checkatrade logo
  • Secured by Design logo
  • Kite Mark logo
  • Kite Mark logo
  • Kite Mark logo