Home Improvement

Solved: How to Cover Old Window Sills with PVC

wooden window sill

All over the country, homeowners are forced to paint old wood window sills and trim year after year.

Even after replacing the window with a new vinyl replacement window, the window sill is still exposed to the elements.

A common remedy is to hire a contractor to bend aluminum to fit over the window sill.

There are a few problems with this method of window sill protection:

  • Matching the window frame color - White aluminum has a different color look than white vinyl;
  • Aluminum still requires maintenance periodically - The paint on the aluminum can chip and peel over time;
  • And finally, if you have a dozen windows to do, the cost of hiring a contractor to perform the labor on all those windows can add up.

The solution is to install PVC - vinyl extrusions made specifically to cover old wood window sills and surrounding trim. No more reconditioning or having to paint them as you do with wood. 

You eliminate any maintenance forever!

See also: How to install bubble wrap on windows?

Window Sill Wrapping Made Easy

Vinyl is a truly maintenance-free product. The window sill extrusion has been pre-formed to fit any window sill in America. That way, homeowners with a basic knowledge of tools can install this product themselves, saving on costly labor charges.

An instructional video will assist you with the project. Read below to learn about the installation video.

The instructional video "Sill Wrapping Made Easy" shows you how to cover the window sill with a PVC extrusion, so you never have to paint again. Also, the video shows you how to cover the remaining exterior wood trim using vinyl angle trim. The end result is a vinyl window exterior that never needs maintenance again!

The Window Sill Wrapping Process

You can paint the sill wrap and angle trim to match the exterior of your home. Krylon makes spray paint for plastic patio furniture that works well. However, keep in mind that paint can peel, chip, and fade over time. Raw vinyl is maintenance-free, but applying paint creates a potential maintenance issue in the future.

The two pictures below show the sill wrap piece being applied. The picture on the left shows how it fits on the wood window sill. The picture on the right shows the piece installed before the end caps are installed. Even the wood trim below the window sill gets covered using a 2" x 2" L-Angle trim.

The pictures below left show the end cap before being cut and installed. The cap is 6 inches long and can do both ends of a sill. Notice the legs on the back. The sealant is applied to the legs to hold the cap in place. The picture below right shows the cap installed.

You can cut the sill wrap with a chop saw using a fine-tooth carbide blade, or you can use a hacksaw if necessary. You can use a hacksaw or jigsaw to accomplish notching.

Here is the end result. Notice that the wood trim below the sill has been covered as well as the wood around the window.

Repairing Wood Window Sills

Homes that were built prior to 1960's usually have wood sash windows. These windows have exterior sloped wood sills to drain water away from the window.

There is also wood trim on the sides and across the top of each window. The window's energy efficiency increases tremendously if you replace the wood sashes with a PVC pocket window.

During the cold winter months, it can drastically reduce heating costs.
But, wait - what about the wood that surrounds your windows on the outside? You have that brick molding around the edge of the opening and the wood sill on the bottom.

You still have to periodically maintain that or even replace it in case of deterioration.
You could solve this by wrapping the wood with aluminum as it is more durable than wood.

But, aluminum also has to be painted, so you are still dealing with a paint issue.
Also, to install the aluminum, a homeowner will need to have a special bending tool. You will have to hire a professional as you do not have the tools or knowledge to use them properly.

However, there is a PVC product that homeowners can install using only basic tools. The end result is a maintenance-free window sill, and it looks better than the aluminum process.

By covering your wood with PVC, you eliminate the need to paint or replace your wood ever again. Your window sill will look like new even if you have some rot in the wood - repair the damaged wood with filler, then install the vinyl cover.

First, remove any paint that is peeling of before attaching the trim. Cut the sill wrap extrusion with a hacksaw or chopsaw, and cut it 1 1/2" longer than the sill itself as you have to attach the caps on the ends.

The sill piece has to be notched to fit around the brick molding on each end. To accomplish that, use a jigsaw or hacksaw.
It is important to use an extreme weather adhesive, like Dynaflex 230. If you use a bond that can't withstand sub-freezing weather, the vinyl can come loose from the wood.

The trim covering the brick molding and surrounding wood is an L-Shaped piece. To fit most applications, the trim comes in several sizes.
You can rip it down using a table saw, jigsaw, or simple plastic cutting tool.

So, no matter what size of wood you have around your windows, the L-Angle trim will fit.

You can learn more about this wrapping process on youtube: