Guide To Capping Windows

Our guide to capping windows will go through the basic process and costs associated with this add on service. Many older homes have exterior wood casings or molding around the windows that require periodic painting to insure that the wood does not rot or deteriorate. Window capping is the process of covering and completely sealing the wood casing to both protect the wood and create a maintenance free window covering.

The process is done with either a vinyl coated aluminum or a PVC (vinyl) trim coil. Each piece is custom sized and cut using a specialized tool on the job site to fit the window trim. The outside edges are then caulked with a high quality silcone sealant to create a watertight seal. The result is a nice looking exterior window trim that is virtually maintenance free and should last for 20 years or more.

Jim R. - Site Editor - Updated In October, 2023

Window Capping Cost

Exterior window capping cost will vary based on the company that you use, the grade of materials used and the size and condition of the wood molding. Some companies excel at the process, while other companies don't love to do the work and will bid out that portion of the project high. Finding a company that does the work well is very important.

Generally, window capping cost is $75 to $175 with $125 to $150 per window being the average. The material cost is relatively low, while the labor cost to wrap windows with aluminum is the bulk of the expense.

-- Price Range: $75 to $175 per window --

Type Of Window
Frame Material
Quality Of Window
Type Of Installation
Number Of Windows
Enter Your Zip Code

Benefits And Downsides

The overall benefit here is to protect the wood casings or surround from long term water damage. This is especially important for old homes that are exposed to lots of rain over time. Properly done, aluminum or vinyl capping keeps the exterior trim dry and water-free, saving the homeowner lots of money if they have to repair water damage to the trim, casings, or even inside of their walls.

The downside of vinyl vs aluminum window capping is that it can look kind of cheesy if done incorrectly or if the work is shoddy. I would always make sure to see pictures of previous jobs from the company who you are considering having do the work. You really want to make sure that their cuts are precise and their work is thorough and professional. Done well, window capping looks nice and properly protects the exterior casing -- saving you money and adding to the overall aesthetic of your home.

Cost Of Exterior Window Capping

I love the site, thanks! I in Ohio and have a bid from Okna windows.

18 double hungs using the 500 Series DX, with grids and all standard colors. This will be a pocket install and will include exterior capping and some interior trim work. The bid came in at $19.5K for the 500 series and $21.6K for the Okna 800 series. Does this sound fair for the job? Is the price increase worth it for the 800? We don't plan moving for a very long time.

Mary - Homeowner - October, 2023

Website Editor's Answer

Mary, thanks for reaching out. I would say that for those windows, plus the aluminum window capping and some interior trim work, yes that probably a fair cost quote. Capping can be $75 to $100 a window and trim work can be about the same so I think it sounds like a fair deal. I would upgrade to the 800 if you plan to be in the home longer than 20 years. If less than this, the Okna 500 series is just fine.

Editor John M. - October, 2023

Is Window Capping Necessary?

I have a pretty generic question for you. Is window capping necessary? How bad does it look? My home is over 40 years old and has some wood rot that they said they would cover up with the capping. I don't plan to live here more than maybe 6 years fyi.


Jess - Homeowner - October, 2023

Website Editor's Answer

Jess, exterior capping will protect your outside trim from future water damage. If the installer is good, I think they can look quite nice. Poorly performed jobs are not very nice looking. There is definitely an art to the process.

Replacing wood rot is important, but not for the capping aspect per se. It's important when you install replacement windows as that the frames are the foundation for the windows staying nice and square and plumb over the years. If your frames aren't sound, you will have issues over the years. If your timeline is only 6 years, I might not cap the windows, but it really does depend on the condition of your exterior trim.

Editor John M. - September, 2023

Window Capping Aluminum vs Vinyl

John, thanks for all your help! One additional question...the contractor who is contractor is proposing PVC (vinyl) coated trim vs the other contractor offering aluminum trim coil. Can you tell me if one of these is better than the other? Thanks!

Bill - Homeowner - October, 2023

Website Editor's Answer

Bill, I think it's more about the look than anything else. I would check out some examples of each and see which you like better. I don't think there's any real difference between this although...vinyl might hold up better over time. Bottom line: it all comes down to the installer, that's the key!

Editor John - October, 2023

Aluminum Window Capping

The Marvin dealer wants to use aluminum window capping on my exterior wood trim versus a full gut and replace of the exterior wood trim with PVC. Do you have an opinion on this? Do you know the cost to wrap windows with aluminum? Marvin Windows Reviews

Nick - Homeowner - October, 2022

Website Editor's Answer

Nick, when the aluminum cap is done right, it is very effective at protecting the wood trim from water damage. This video shows what is entailed in the process and is worth a quick look in my opinion.

I'm not sure what I think of the look personally. It really depends on the home, the age of the home, the overall quality of the home, the surrounding materials, etc. Exterior window capping cost is roughly $125 to $150 per opening. For additional costs, check out our replacement cost estimator page.

Editor Jim - October, 2022

Window Capping Installation Question

Hi Jim. Do you recommend placing a cap on the outside trim? The installer I am talking to said he will install the windows from inside as outside install compromises the trim and he does not recommend this as it can create mold and water issues down the road.

I have not found a lot of research on that. For me capping is more saving on pairing and can improve esthetics of the windows if you are looking for more contemporary straight lines.

Thank you for your valuable insights.

Vlad - Homeowner - May, 2021

Website Editor's Answer

Vlad, this process of adding a cap to the trims simply protects the exterior wood trim. Properly done, it shouldn't create problems (just the oppoiste), but improperly done, he is correct. It really depends on the condition of your existing surrounds. Some people paint every five years or so and some homeowners don't want to deal with the hassle...

Placing a cap on the windows does make for a cleaner look. Decide if you like the look and if so, make sure that the installer who will be doing the work feels really comfortable with the process and does it enough that he is going to do a good job.

Editor Jim R. - May, 2021

Type Of Window
ProVia Window Series
Installation Needs
Number Of Windows
Enter Your Zip Code