Window Sill Replacement Options

Published September 17, 2021
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Lake Washington Windows

When replacing, preparing, or modifying an existing old window, you should probably re-fit your old window sill as well. Companies like Lake Washington Windows and Doors install interior/exterior window sills affordably. Before you chose a window sill replacement company, make sure they use high-quality materials and a company with a variety of replacement window sill options.

Reasons to Replace a Window Sill

There are many reasons to replace your interior window sill even if it is not failing. Some common reasons are below:

  • Water damage
  • Compromised structural integrity
  • Retrofitting new windows
  • Remodeling for a new look

For those encountering operational issues, our Milgard window troubleshooting section offers insight on addressing common problems.

Old Window Sill is Rotting, Warped, or Damaged

All window sills are exposed to extreme heat and moisture. Because of this, the water and sun can cause damage, rotting, and warping. Houses with an old sill, rotten wood, or damage near the sill horn, should be repaired or replaced. Depending on the severity of the damage, you may need or replace your interior window sills and/or exterior apron.

Your old horizontal shelf (sill) can be replaced with PVC sills or modern wooden sills.

Installing New Replacement Windows

Replacing and installing new windows will add value to your home and improve your comfort level tremendously. When you are ready to replace your windows you’ll need to determine what kind of new window you are looking for.

The most commonly replaced windows are below:

  • Double-hung windows
  • Awning style windows
  • Sliding glass doors
  • Casement style windows
  • Fixed windows
  • Hopper style windows

All replacement windows are different and some windows are many years old, which means most new windows are customized to fit the exact window you are replacing. After you determine the dimensions and have the window in hand, you have to carefully remove the old window then install a new one. This is a good time to consider replacing your old window sills.

Extending Length / Use as a Shelf

An interior sill has a dual purpose. It helps prevent structural damage while also allowing you to decorate it. When you extend the sill you add surface area which can be used as a shelf. If your house has an old small wooden window sill, there are ways to extend it.

Use a Different Materials for a New Look

Replacing an old sill with new material is the best way to change the look and feel of your space. Before you start any window construction, remember to analyze the benefits and drawbacks of the materials being considered. For example, certain wood like Pine has antiseptic properties, and lack moisture-resistant characteristics.

The most common window sill material is below:

  • PVC (polyvinyl chloride)
  • Stone (lasts practically forever)
  • Wood (thermal insulating)

Improve Durability, Strength, & Weather Resistance

Your window sill is rigid because it helps eliminate the flexing to support the structure of the window frame. Additionally, window sills play an important role in the functionality of a window. Not only does the sill provide a stopping place for the lower rail of a window, but it also effectively holds the sash in place after the window is closed. Furthermore, the overall design and functionality provide the best weather resistance possible.

What is the best material for a window sill?

The best kind of sill material depends on your preference and the application, such as for living room windows or for kitchen windows. The most durable and long-lasting material is stone. Stone doesn’t fade, requires relatively little maintenance, and is very durable. People prefer stone because it holds its seal, and is cost-effective.

Wooden Window Sills

Wooden window sills are elegant but require some attention over time. Because wood is more sensitive to light and water, you could end up repairing or replacing your sill more often.

Some popular species of wood that you can use for a wooden window sill are below:

  • Solid oak
  • Pine
  • Larch
  • Cherry
  • Ash
  • Chestnut
  • Maple
  • Mahogany
  • Beech

Tile Window Sills

Tile is a popular option when considering materials for a new sill. Most tile is made out of glass and ceramics which means it is moisture and sunlight-resistant.

Some additional benefits to using tile are below:

  • Easy to clean and maintain
  • Tile is relatively inexpensive
  • Tile is high-customizable

Stone Window Sills

There are many advantages to using stone for a window sill. For example, stone window sills resist damage from sunlight, fire and will retain their attractive appearance for years requiring very little maintenance. Additionally, the stone is moisture resistant and when polished, is easy to clean.

Some stone materials include:

  • Granite
  • Limestone
  • Marble
  • Slate

Metal Window Sills

Metal sills are very functional and affordable.

Your external window sill is typically fixed with a small incline outwards and downwards. It’s common for aluminum to be used for exterior window sills because it is a modern material that is extremely weather-resistant.

Some additional metals that are used for window sills are copper, stainless steel, bronze, and nickel.

Plastic / PVC Window Sills

PVC moldings are easy to work with, weather-resistant, and durable. Unlike wood sills that use nails in your house, PVC has to be glued with adhesives or mortar at the bottom portion. After you build a PVC sill, place heavy objects on top and properly apply caulk to enhance the bond with the base surface.

How much does it cost to replace window sills?

The average cost for a simple window sill replacement is between $240 and $524 for both parts and labor. The sill is the ledge that peaks out at the bottom of your window. You should replace this part anytime it feels loose, has rotted, or has broken edges. When you’re replacing windows in your home, ask your window replacement company about the cost to replace sills at the same time.

Should you redo a window sill when you replace your windows?

Always replace your sill anytime the structure or appearance of your window is compromised due to sill failure or age. Companies like Lake Washington Windows and Doors have experienced carpenters who know how to slowly pry and remove your old sill as they install your new windows.

Additional reasons to redo your sill at the same time as your windows are below:

  • You uncover rot
  • Discover a bug infestation
  • Substructure damage

Should you hire a window replacement company do it or DIY?

DIY Windows and new window sill replacement can be complex and time-consuming. Also, if you are a first-timer, you could have to acquire all new tools. The best part of hiring a company like Lake Washington Windows and Doors is the installation warranty. Plus, a professional will save you time and energy.

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Written by Lake Washington Windows

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