• Home
  • DIY
    • Self build
    • Projects and advice
      • Bathroom
      • Building, brickwork and masonry
      • Ceilings
      • Cleaning
      • Concrete work
      • Damp, rot and infestation
      • Drains
      • Electrical
      • Fireplaces
      • Floors
      • Garden
      • Heating
      • Insulation
      • Kitchen
      • Lighting
      • Lofts
      • Painting and decorating
      • Plasterwork
      • Plumbing
      • Roof and guttering
      • Safety
      • Security
      • Tiling
      • Walls
      • Windows
      • Woodwork
    • Glossary
    • Know your tools
    • Know your materials
  • Cost guides
  • News
  • Community
Facebook Twitter Instagram
lets-do-diy.com
  • Home
  • DIY
    • Self build
    • Projects and advice
      • Bathroom
      • Building, brickwork and masonry
      • Ceilings
      • Cleaning
      • Concrete work
      • Damp, rot and infestation
      • Drains
      • Electrical
      • Fireplaces
      • Floors
      • Garden
      • Heating
      • Insulation
      • Kitchen
      • Lighting
      • Lofts
      • Painting and decorating
      • Plasterwork
      • Plumbing
      • Roof and guttering
      • Safety
      • Security
      • Tiling
      • Walls
      • Windows
      • Woodwork
    • Glossary
    • Know your tools
    • Know your materials
  • Cost guides
  • News
  • Community
lets-do-diy.com
You are at:Home»Projects and advice»Windows – minor repairs

Windows – minor repairs

Summary: Learn how to make repairs to a window, replace a pane of broken glass, fit a new pane of glass, free a sticking casement window, repair a stiff sash mechanism, adjust a mortise fastener and repair a rotten window sill.


Stick masking tape over the pane to prevent the glass fragmenting.

Replacing a pane of broken glass

When removing a cracked windowpane, wear protective gloves and goggles.

  • Place a dustsheet under the window to catch any loose glass.
  • To prevent glass fragmenting, stick masking tape over each pane.
  • Tap the glass with a hammer to knock it out and careafully pull out pieces of glass from the frame by hand.
  • Use a putty knife or chisel to remove any putty and remaining glass.
  • Remove all pins and diamond-shaped glazing points with pincers or pliers.
  • Sand the frame lightly to ensure the surface is smooth.
  • Clean out the rebate frame and apply wood preserver and primer before inserting new glass.

Push the rolled putty into the rebate.
Trim the excess putty with a putty knife.

Fitting a new pane of glass

  • Take some putty and roll it in your hands until it has a smooth consistency which will make it easier to work with.
  • Roll the putty into strips of about 10mm (3/8in) in diameter and push the strips into the rebate.
  • Carefully position the new pane of glass into the rebate and press around the edges, so the putty holds it.
  • Using a pin hammer carefully tap glazing points or small pins into the timber frame around the pane of glass to keep it in place. The glazing sprigs or pins should not touch the pane of glass.
  • Push more strips of putty all around the pane of glass where it meets the rebate.
  • Trim away any excess putty with a putty knife. Then run the flat surface of the knife’s blade over the putty to a secure seal and smooth finish.
  • Clean any smears from the glass with white spirit.
  • Wait until the putty has dried before painting.

Freeing sticking casement windows

  • First try running a knife down the edges of the window to remove any paint or debris clogging the joint or tracks of the window.
  • Lubricate the edge of the window with candle wax.
  • If neither of these methods work, pull the window in to the frame as if closing it but without actually doing so and inspect the edge where it meets the frame. You should be able to see where the window is sticking.
  • Use a plane to shave off the area causing the window to stick.
  • If the window is sticking on the vertical edge you will be able to remedy the problem without removing the casement. But if the problem is on either the top or bottom edge it will have to be removed before planing.

Repairing stiff sash mechanisms

If a sash window is sticking, oil the mechanism and strip off any excess paint clogging the track. If this does not work, you may need to replace the cords, which is covered in replacing broken sash cords.


Use the cut out section as a template but cut your patch slightly bigger.
Plane the surface smooth.

Adjusting a mortise fastener

If the mortise fastener is not securely holding the window in the closed position it may be misaligned. You will need to remove the mortise-plate on the mullion and reposition it.

  • With a screwdriver remove the mortise-plate.
  • Position the plate so that the fastener connects with the mullion in the middle of the plate.
  • Draw around the central hole in the plate, and then around the outside of the plate.
  • Mark the position of screw holes and drill pilot holes.
  • Chisel out the central hole to a depth that will accommodate the mortise.
  • Screw the mortise plate to the mullion, and check the alignment.






Chisel out the central hole to a depth to accommodate the mortise.

Repairing a rotten sill

If a section of the sill is rotten or damaged, you can patch it rather than replacing the entire sill.

  • Use a hand saw to cut out the area of rotten wood as neatly as possible. Cut the ends to a mitre cut.
  • Use the section you cut out as a template for the patch but making it slightly bigger. Cut the patch with a mitred end to make a mitre joint with the existing sill.
  • Mark the position of the drip groove (drainage channel) under the sill.
  • Use a router to carve out a drip groove in the patch.
  • Apply primer to the cut edges.
  • Screw the patch in position with countersunk screws.
  • Plane the surface to a smooth finish and decorate.
  • If a large portion of the sill is rotten, then prise the sill away from the window and fashion a replacement, using the old section as a template. Widespread rot may require you to replace the entire window.

Tools needed

  • Claw hammer
  • Putty knife
  • Pincers OR pliers
  • Paintbrush
  • Pin hammer
  • Pen knife
  • Plane
  • Screwdriver
  • Power drill
  • Wood chisel
  • Panel saw
  • Router
  • Countersink drill bit

Materials needed

  • New pane of glass
  • Masking tape
  • Sandpaper
  • Wood preserver
  • Primer
  • Putty
  • Glazing sprigs OR pins
  • White spirit
  • Candle wax
  • Screws
  • Sandpaper

Related projects

  • Building a metal framed stud wall
  • Building a stud partition wall
  • Creating an arch
  • Closing a fireplace
  • Fitting a door frame
  • Fitting a door stop

Related cost guides

  • Average cost to build a garage
  • Average cost of a hot tub
  • Average cost to install a shower
  • Average window cleaning cost
  • Average cost of double glazing
  • Average cost of a sash window
  • Average cost to tile a bathroom

Recent Comments
  • Vic on Is Christmas a good time for DIY?
  • Anonymous on Average air source heat pump cost (2022)
  • Reggie on Prepare your home for moth season
Latest News
0

Potential DIY home improvement trends for 2023

1

Is Christmas a good time for DIY?

0

Design trends for 2022 and 2023

0

Product Review: Handsaws

Popular Guides

Average chimney repair costs

Average cost to install a toilet

Average soundproofing cost

Average gas cooker installation cost

Popular Projects

Wallpapering a stairwell

How to skim plasterboard

Laying a plywood subfloor

Cleaning a paint brush or roller

DIY Categories
Bathroom
Building, brickwork and masonry
Ceilings
Cleaning
Concrete work
Damp, rot and infestation
Drains
Electrical
Fireplaces
Floors
Garden
Heating
Insulation
Kitchen
Lighting
Lofts
Painting and decorating
Plasterwork
Plumbing
Roof and guttering
Safety
Security
Tiling
Walls
Windows
Woodwork

Self Build Guide
How to find a building plot
Evaluating a building plot (2023)
How to get a self build mortgage
Self build construction options
Self build architect and design considerations (2023)
Self build planning permission and legal consents
© 2023 lets do diy ltd | ebuild
  • Home
  • About
  • Contact us

Type above and press Enter to search. Press Esc to cancel.

We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
Cookie SettingsAccept All
Manage consent

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
CookieDurationDescription
cookielawinfo-checkbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
Functional
Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
Performance
Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.
Analytics
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
Advertisement
Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.
Others
Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.
SAVE & ACCEPT