How To Replace An Interior Window Sill - DIY - PJ Fitzpatrick

Home » How To Replace Window Sill » How To Replace An Interior Window Sill - DIY - PJ Fitzpatrick

Maybe your like

Call For Free Estimate 1-877-246-4354 P.J. Fitzpatrick
  • Home Repairs
    • Storm Damage Repair
    • Real Estate Repair
    • Residential Repair Contractor
    • Affordable Home Repair
    • Exterior Home Renovation
  • Roofing
    • Roof Repairs
      • Emergency Roof Repair
    • Roof Replacement
    • Types of Roofing
      • Architectural Shingles
      • Cedar Shingles
      • CertainTeed Shingles
      • Cool Roof Technology
      • Copper Roofing
      • Flat Roofing
      • Luxury Shingles
      • Metal Roofing
      • Slate Roofing
      • Tile Roofing Shingles
    • Specialty Roofing
      • Historic Roof Repair
      • Historic Roof Replacement
      • Cedar Shingles
      • Copper Roofing
      • Slate Roofing
      • Tile Roofing
    • Commercial Roofing
      • EPDM Flat Roofing
      • Commercial Metal Roofing
      • TPO Flat Roofing
    • Recommended Roofers
    • Additional Services
      • Attic Insulation with New Roof
      • Chimney Caps & Pipe Collars
      • Copper Chimney Flashing
      • HOA Roofing
      • Roof Flashing
      • Roof Leaks
      • Roof Ventilation
      • Skylights
    • Resources
      • How to Inspect Your Roof
      • Is it Time to Replace Your Roof
      • What You Need to Know
      • Installation Process
      • Photo Gallery
  • Windows
    • Window Replacement
    • Window Installation
    • Window Repair
    • Vinyl Window Installation
    • Types of Windows
      • Awning Windows
      • Bay Windows
      • Black Vinyl Windows
      • Bow Windows
      • Casement Windows
      • Custom Shaped Windows
      • Double-Hung Windows
      • Garden Windows
      • Glider Windows
      • Picture Window
      • Round-Top Windows
    • Resources
      • Installation Process
      • Photo Gallery
  • Siding
    • Siding Repairs
    • Siding Installation
    • Siding Replacement
    • Local Siding Company
    • Siding Types
      • Vinyl Shake and Shingle Siding
      • Vinyl Horizontal Siding
      • Vertical Vinyl Siding
      • Vinyl Siding Colors
    • Resources
      • Installation Process
      • Photo Gallery
  • Gutters
    • Gutter Repairs
    • Gutter Installation
    • Rain Gutter Repair
    • Gutter Cleaning
    • Gutter Guards
    • Yankee Gutter Repair
    • Ice Dam Removal
    • Photo Gallery
  • Doors
    • Door Repairs
    • Door Installation
      • Front Door Replacement
    • New Front Door
    • Door Types
      • Exterior French Doors
      • Fiberglass Front Doors
      • Sliding Glass Doors
      • Wood Front Doors
    • Garage Doors
      • Garage Door Installation
      • Garage Door Repair
      • Amarr Garage Door Products
    • Resources
      • Door Samples & Materials
      • Photo Gallery
  • Baths
    • One Day Bath Replacement
    • Bathtub Replacement
    • Shower Replacement
      • Walk-In Showers
    • Shower Remodel
    • Bathroom Remodel
    • Bathrooms for Seniors
    • Tub to Shower Conversion
      • Replacing Bath With A Shower
    • Shower To Tub Conversions
    • Walk-In Bath
    • Resources
      • Questions & Answers
      • Bath & Shower Maintenance
      • Bath Comparisons
      • Photo Gallery
  • Financing
  • Specials
  • Careers - We're Hiring!
  • Recent Projects
  • Do It Yourself
  • Pay Bill
  • Customer Service
  • Live Chat
  • Refer A Friend
  • Online Estimate
Call For Free Estimate 1-877-246-4354 Get Online Estimate Default header image DIY Logo The do it yourself resource for homeowners from home improvement professionals.

Several different things can affect a window sill and cause a need for replacement, from condensation to sun damage to warping and more. As long as you have the right tools, a new piece of wood for your new sill, and some patience, you can replace it yourself. Here, our window replacement experts tell you how to replace an interior window sill:

  1. The first step for how to replace an interior window sill is using your utility knife to cut the caulk between the window sill and the trim.
  2. Next, cut underneath the window sill to free the sill from the trim board under it.
  3. After that, place your putty knife between the wall and the trim and pry the trim away from the wall. If needed, use your pry bar or chisel to complete the task.
  4. Once all of your trim is lifted away, use your pliers to remove all of the finishing nails in it.
  5. Open the window, then use your putty knife to remove the side window trim.
  6. Next, wedge your pry bar or chisel underneath the window sill and loosen it as much as possible.
  7. Repeat step 6 on all sides of the sill until it comes loose and you can easily remove it.
  8. Scrape away any old glue, caulk, or debris from the framing to prepare it for your new window sill.
  9. Place your old window sill on top of your new piece of wood and use a pencil to trace the exact shape onto the wood.
  10. Cut out your new window sill with your table saw.
  11. Next, place your new window sill where your old window sill was to make sure it’s the right fit. If not, make adjustments as needed.
  12. When you have the exact shape you want, use sandpaper to sand down the edges.
  13. Next, paint or stain the window sill to match the surrounding woodwork.
  14. Once it’s dry, tap the finished window sill into place using your rubber mallet.
  15. After that, use your hammer to drive finishing nails into the back of each corner.
  16. Continue to secure with nails every 8-10 inches along the back.
  17. Re-install your side trim and the trim from underneath the sill.
  18. Set your nails using a nailset, then fill in any holes using wood putty.
  19. Finally, re-caulk your seams, corners, and cracks.
How to Replace an Interior Window Sill

Tools & Materials

  • Utility knife
  • Putty knife
  • Pry bar or chisel
  • Pliers
  • Wood
  • Pencil
  • Table saw
  • Sandpaper
  • Paint or stain
  • Rubber mallet
  • Hammer
  • Finishing nails
  • Nailset
  • Wood putty
  • Caulk

Need help with this project?

We have trained professionals that can help. Contact us today. 1-877-246-4354

Get Free Estimate

Home Improvement

  • How to De-ice A Roof
  • How To Get Leaves Off Of A Roof
  • How To Mount A TV On Vinyl Siding
  • How To Remove A Stripped Screw
  • How To Repair Damaged Drywall

Siding Installation

  • How to Choose the Right Siding Color for Your Home
  • How to Make Siding Look Like Wood
  • How To Replace Home Siding
  • How to Install the Top Piece of Vinyl Siding
  • How to Install Vinyl Siding Mounting Block

Gutter Repair

  • How to Seal Gutter Joints
  • How to Install a Gutter Liner System
  • How to Clear Clogged Gutters
  • How to Repair Leaking Gutters
  • How to Remove a Downspout

Roof Repair

  • How to Safely Tarp a Roof
  • How to Fix a Shingle Roof Valley
  • How to Prevent Roof Damage This Winter
  • How to Clean a Roof
  • How to Find a Leak in My Roof

Installing Insulation

  • How to Insulate a Roof Without an Attic
  • How to Blow In Insulation
  • How to Insulate a Crawl Space
  • How to Insulate a House
  • How to Insulate a Garage

Window Replacement

  • How to Remove a Window
  • How to Remove Home Windows
  • How to Replace Exterior Window Trim and Seal Against Water Damage
  • How To Prepare An Older Home For Window Replacement Without Interior Damage
  • How to Replace Vinyl Windows

Door Installation

  • How to Measure a Storm Door
  • How to Replace a Patio Door
  • How to Replace a Sliding Glass Door
  • How to Install a Prehung Exterior Door
  • How to Build an Insulated Exterior Door

Shower Installation

  • How to Install a Hand Shower with Slide Bar
  • How To Install a Shower Pan
  • How to Replace a Shower Drain
  • How to Install a Shower Door
  • How to Install a Walk In Shower

Bathtub Installation

  • How to Replace a Shower Pan
  • How To Remove A Cracked Shower Pan
  • How to Install a Fiberglass Tub and Shower Surround
  • How to Remove a Cast Iron Tub
  • How to Fit a Bath

Gutter Installation

  • How to Install Gutter Flashing
  • How to Install Gutters on a Metal Roof
  • How To Inspect Fascia and Roof Edges Before Installing New Gutters
  • How to Choose the Right Gutter Size
  • How to Install Vinyl Gutters

Siding Repair

  • How to Fix Missing Siding Panels
  • How to Fix Missing Siding
  • How to Remove and Replace Rotting Fascia Boards
  • How To Paint Aluminum Siding
  • How To Repair Cracks In Stucco Siding

Shower Repair

  • How To Regrout A Tile Shower
  • How to Replace a Shower Head
  • How to Replace Shower Caulk
  • How to Replace a Shower Handle
  • How to Remove Shower Wall Surround

Roofing Installation

  • How to Vent A Water Heater Through Your Roof
  • How to Install a Shingle Roof
  • How to Build a Roof Over My Existing Deck
  • How To Remove Asphalt Shingles
  • How to Hang Shingles

Bathtub Maintenance

  • How to Install a Grab Bar in a Shower
  • How to Install a Shower Bench
  • How to Replace Grout In a Shower
  • How to Move a Bathtub Drain
  • How to Fix a Leaky Bathtub Faucet

Window Repair

  • How To Seal A Window Leak
  • How To Cover Windows For Winter
  • How to Remove Home Windows
  • How To Replace A Rotten Window Sill Without Removing The Window
  • How to Replace Exterior Window Trim and Seal Against Water Damage

Window Installation

  • How to Build Your Own Storm Windows
  • How to Build Plexiglass Storm Windows
  • How to Install a New Window
  • How to Measure Window Screens
  • How to Install Window Flashing Tape

Door Repair

  • How to Repair a Door Frame
  • How to Replace a Door Knob
  • How To Fix A Door That Rubs At The Top
  • How to Repair a Drafty Front Door
  • How to Paint a Front Door

PJ Fitzpatrick, LLC

21 Industrial Blvd. New Castle, DE 19720

6380 Flank Dr. #600 Harrisburg, PA 17112

141 Delta Dr. Suite D Pittsburgh, PA 15238

1000 Prime Place. Hauppauge, NY 11788

2 Cranberry Rd. #A5 Parsippany, NJ 07054

5061 Howerton Way. Suite L Bowie, MD 20715

10189 Maple Leaf Ct. Ashland, VA 23005

2551 Eltham Ave. Suite L Norfolk, VA 23513

8407 Firebird Dr. Ste 200, Fairfield, OH 45011

Connect With Us

Check out our social pages or our reviews page and let us know how we’re doing!

FacebookTwitterYouTubeInstagramLinkedin read our reviews

Our Services

Our Latest Blog Post

Recent Posts

  • Ice Damming: What It Is, Why It Happens, And How To Prevent It

View All

© 2026 PJ Fitzpatrick, LLCNJ Lic. #13VH10727200 | DE Lic. #2009603070 | PA Lic. #PA011323 | MD Lic. #130457WDC Lic. #420223000113 | VA Lic. #2705189958 | Suffolk NY Lic. #HI-61468 | Nassau NY Lic. #151702 | NYC Lic. #2128461-DCWPNJ Plumbing Lic. David Geiger # 36BI01232300 | MD Plumbing Lic. #98756 | OH Plumbing Lic. #48314 | IN Plumbing Lic. #CO52600002 Website by the Prager Microsystems, Inc. Digital Marketing Agency

Tag » How To Replace Window Sill