--- title: How to Fix a Dropped Sash in a uPVC Window description: "How to fix a dropped sash in a uPVC window: what toe and heeling means, how glaziers realign the glass, and why this repair is best left to a professional." --- [![SM\_Logo\_Final\_Lught](https://smwindowsanddoors.co.uk/hs-fs/hubfs/SM_Logo_Final_Lught.webp?width=140&height=80&name=SM_Logo_Final_Lught.webp "SM_Logo_Final_Lught")](https://smwindowsanddoors.co.uk) - About - [About](https://smwindowsanddoors.co.uk/about) - Doors - [uPVC Doors](https://smwindowsanddoors.co.uk/upvc-doors-york) - [Sliding & Bifold Doors](https://smwindowsanddoors.co.uk/aluminium-sliding-bi-fold-doors) - [Composite Doors](https://smwindowsanddoors.co.uk/composite-doors-york) - [Heritage Aluminium Doors](https://smwindowsanddoors.co.uk/heritage-aluminium-windows-doors) - [Door Repairs](https://smwindowsanddoors.co.uk/window-door-repairs-york) - Windows - [uPVC Windows](https://smwindowsanddoors.co.uk/upvc-windows-york) - [Casement Windows](https://smwindowsanddoors.co.uk/casement-windows-york) - [Sash Windows](https://smwindowsanddoors.co.uk/sash-windows-york) - [Timber Windows](https://smwindowsanddoors.co.uk/timber-windows-york) - [Heritage Aluminium Windows](https://smwindowsanddoors.co.uk/heritage-aluminium-windows-doors) - [Lanterns & Roof Lights](https://smwindowsanddoors.co.uk/korniche-lanterns-flat-roof-lights) - [Window Repairs](https://smwindowsanddoors.co.uk/window-door-repairs-york) - Conservatories - [Conservatories](https://smwindowsanddoors.co.uk/conservatories-orangeries-york) - [Orangeries](https://smwindowsanddoors.co.uk/conservatories-orangeries-york) - Resources - [Gallery](https://smwindowsanddoors.co.uk/gallery) - [Brochures](https://smwindowsanddoors.co.uk/brochure-downloads) - [Blog](https://smwindowsanddoors.co.uk/blog) - [Reviews](https://smwindowsanddoors.co.uk/customer-reviews) - [Contact Us](https://smwindowsanddoors.co.uk/contact) [Request A Quote](https://smwindowsanddoors.co.uk/request-a-quote) [![SM\_Logo\_Final\_Lught](https://smwindowsanddoors.co.uk/hs-fs/hubfs/SM_Logo_Final_Lught.webp?width=140&height=80&name=SM_Logo_Final_Lught.webp "SM_Logo_Final_Lught")](https://smwindowsanddoors.co.uk) [Request A Quote](https://smwindowsanddoors.co.uk/request-a-quote) - About - [About](https://smwindowsanddoors.co.uk/about) - Doors - [uPVC Doors](https://smwindowsanddoors.co.uk/upvc-doors-york) - [Sliding & Bifold Doors](https://smwindowsanddoors.co.uk/aluminium-sliding-bi-fold-doors) - [Composite Doors](https://smwindowsanddoors.co.uk/composite-doors-york) - [Heritage Aluminium Doors](https://smwindowsanddoors.co.uk/heritage-aluminium-windows-doors) - [Door Repairs](https://smwindowsanddoors.co.uk/window-door-repairs-york) - Windows - [uPVC Windows](https://smwindowsanddoors.co.uk/upvc-windows-york) - [Casement Windows](https://smwindowsanddoors.co.uk/casement-windows-york) - [Sash Windows](https://smwindowsanddoors.co.uk/sash-windows-york) - [Timber Windows](https://smwindowsanddoors.co.uk/timber-windows-york) - [Heritage Aluminium Windows](https://smwindowsanddoors.co.uk/heritage-aluminium-windows-doors) - [Lanterns & Roof Lights](https://smwindowsanddoors.co.uk/korniche-lanterns-flat-roof-lights) - [Window Repairs](https://smwindowsanddoors.co.uk/window-door-repairs-york) - Conservatories - [Conservatories](https://smwindowsanddoors.co.uk/conservatories-orangeries-york) - [Orangeries](https://smwindowsanddoors.co.uk/conservatories-orangeries-york) - Resources - [Gallery](https://smwindowsanddoors.co.uk/gallery) - [Brochures](https://smwindowsanddoors.co.uk/brochure-downloads) - [Blog](https://smwindowsanddoors.co.uk/blog) - [Reviews](https://smwindowsanddoors.co.uk/customer-reviews) - [Contact Us](https://smwindowsanddoors.co.uk/contact) [Repairs & Maintenance](https://smwindowsanddoors.co.uk/blog/tag/repairs-maintenance) # How to Fix a Dropped Sash in a uPVC Window By [SM Windows & Doors](https://smwindowsanddoors.co.uk/blog/author/sm-windows-doors) Nov 4, 2026, 2:30:00 PM 3 Minutes Read If the glass in your uPVC window has dropped and you are wondering how do I adjust it, the honest answer is that the fix, called toe and heeling, is straightforward for a glazier but fiddly to get right yourself. When a sash drops, the glass has shifted in the frame and needs repacking to sit square again. Here is what a dropped sash actually is, how the repair works, and why it is one of the jobs worth handing to someone who does it every day. ## What a dropped sash is The opening part of a window is the sash, and the sealed glass unit inside it is doing more than filling the hole. In a well made uPVC window the glass is packed at set points so it braces the sash and keeps it square. Over the years, or if the packing was never right, that support can shift and the sash drops under the weight of the glass. You will notice it because: - The window catches on the frame at the bottom corner. - The gap around the sash is tight on one side and wide on the other. - The handle no longer lines up with its keep so the window is hard to lock. The frame has not broken. The glass has simply settled out of position, and it needs bringing back. ## What toe and heeling means Toe and heeling is the technique glaziers use to square a sash up using the glass itself. The sealed unit is surprisingly rigid, so packing it correctly braces the whole sash. In plain terms: - The **toe** is the packer placed low on the hinge side and high on the opening side. - The **heel** is the packer diagonally opposite. - Setting these packers pushes the sash back square, so it swings and locks properly again. Done right, the glass does the structural work and the sash stops dropping. Done wrong, you can strain the sealed unit, break the edge seal (which causes misting later) or crack the glass. ## How the repair is done To realign a dropped sash, a glazier will usually: 1. Take the beading off around the glass, using a bolster to spring it out without damage. 2. Ease the sealed unit free and check the existing packers. 3. Reset the packers at the toe and heel points so the sash sits square. 4. Refit the glass, tap the beading back in and check the window opens and locks cleanly. It looks simple written down, but judging the packing, handling a heavy sealed unit and getting the beading back without marking the frame all take practice. This is why it sits firmly in the repair category rather than a weekend job. ## Why this is best left to a glazier We are straight with people about DIY, and this is one to think twice about. Removing the beading and the glass on a live window risks the sealed unit, and a dropped unit is heavy and awkward. Pack it wrong and you can end up with a misted pane or a cracked one, which turns a small adjustment into a new glass unit. A glazier carries the right packers, a glass sucker and the knack to do it in one visit. Our [window repair team](https://smwindowsanddoors.co.uk/window-door-repairs-york) handles dropped and misted uPVC units across York and North Yorkshire, and we will tell you honestly whether toe and heeling will hold or whether the sash or unit is past it. If the whole window is tired, our [uPVC window range](https://smwindowsanddoors.co.uk/upvc-windows-york) shows the replacement options. ## What you can do yourself first Before you assume the worst, rule out the simple causes. Clean the hinge track, clear grit from the frame and lubricate the hinges, because a window that sticks from grime can look like a dropped sash. If the gap around the sash is even and it just needs freeing off, that is a five minute fix. If the gap is clearly uneven and the glass has slumped into one corner, that is a genuine drop, and that is the point to call someone in. ## FAQs ### Can I adjust a dropped uPVC window sash myself? You can clean and lubricate the hinges yourself, but realigning the glass by toe and heeling means removing the beading and the sealed unit, which is heavy and easy to damage. Because a mistake can crack or mist the glass, most people are better off having a glazier reset it. ### What does toe and heeling a window mean? Toe and heeling is packing the sealed glass unit at diagonal points inside the sash so the rigid glass braces the frame and holds it square. The toe sits low on the hinge side, the heel diagonally opposite. It is the standard way to correct a sash that has dropped. ### Why has the glass in my uPVC window dropped? Usually the packers that support the glass have shifted, or were never set correctly, so the weight of the sealed unit has pulled the sash out of square over time. It is a common repair on older uPVC windows and is fixed by repacking the glass rather than replacing the window. ### Will fixing a dropped sash stop it happening again? If it is repacked correctly, yes, because the glass then braces the sash the way it should. If the hinges are worn or the sash itself has weakened, those may need attention too. A glazier will check the hardware while they have the glass out. Want to see the full range of styles and finishes? [Download our latest brochure](https://smwindowsanddoors.co.uk/brochure-downloads), or [request a free quote](https://smwindowsanddoors.co.uk/request-a-quote) and we will pop out for a look. #### SM Windows & Doors Author ## Phone: 07833387823 Email: [Sam@smwindowsanddoors.co.uk](mailto:Sam@smwindowsanddoors.co.uk) Opening times: Mon - Fri: 09:00 - 17:00 Sat-Sun: By Prior Appointment [Follow us on Facebook](https://www.facebook.com/people/SM-Windows-Doors/100093013267883/) [Follow us on Instagram](https://www.instagram.com/smwindowsanddoors/) ![x59dcc190ea7d320001f0083a\_logoAsset-2-1.jpg.pagespeed.ic.lk8k-280iY](https://smwindowsanddoors.co.uk/hs-fs/hubfs/x59dcc190ea7d320001f0083a_logoAsset-2-1.jpg.pagespeed.ic.lk8k-280iY.jpg?width=300&height=106&name=x59dcc190ea7d320001f0083a_logoAsset-2-1.jpg.pagespeed.ic.lk8k-280iY.jpg "x59dcc190ea7d320001f0083a_logoAsset-2-1.jpg.pagespeed.ic.lk8k-280iY") ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "SM Windows & Doors", "url" : "https://smwindowsanddoors.co.uk/blog/author/sm-windows-doors" }, "dateModified" : "2026-11-04T14:30:00.733Z", "datePublished" : "2026-11-04T14:30:00.000Z", "headline" : "How to Fix a Dropped Sash in a uPVC Window", "mainEntityOfPage" : { "@id" : "https://smwindowsanddoors.co.uk/blog/sm-windows-doors-blog/how-to-fix-a-dropped-sash-in-a-upvc-window", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://smwindowsanddoors.co.uk/hubfs/SM_Logo_Final_Lught.webp" }, "name" : "SM Windows & Doors" } } ```