The worst thing you can do is nothing. A failing sill leaks water into the brickwork below, rotting internal joist ends and plaster. In that context, even the highest repair quote is preventative medicine. Just do it with lime, take your time, and your Victorian window sill will see the next century in.
Avoid epoxy for anything but a stopgap. It’s too hard, doesn’t breathe, and often causes more damage behind the repair. The Gold Standard: A Lime-Based Repair (Step-by-Step Review) I chose option 1 for two sills with surface spalling. Here is my honest review of the process. repair victorian stone window sill
| Method | Best For | Lifespan | Cost (UK, per sill) | Aesthetic Match | DIY-able? | | :--- | :--- | :--- | :--- | :--- | :--- | | | Small spalls, cracks, surface erosion | 20+ years | £150 - £300 | Excellent (invisible) | Yes (with skill) | | 2. Indenting (Replacing a section) | Deep cracks, missing corners, isolated damage | 50+ years | £400 - £800 | Excellent (new stone) | No (professional) | | 3. Full replacement | Complete structural failure, 70%+ damage | 100+ years | £800 - £1,500+ | Good to excellent | No | | 4. Epoxy/resin repair | Emergency or temporary fix | 3-5 years | £50 - £150 | Poor (shiny/plastic) | Yes (easy) | The worst thing you can do is nothing
