The basics of the anatomy of a wood window might seem a bit complex, so we wanted to take a moment to go through some of the common terminology you might hear to help you better understand your windows.

Feel free to click on the Interior or Exterior image to see a larger view.

Interior Wood Window Diagram

Interior Wood Window

The interior diagram on your left shows you all of the parts to a wood window.  Below we will go into further detail some of the terminology you will need to understand when discussing or reading through an estimate for your project.

  1.  Lower and Upper Sash – when we talk about your window, the two main pieces we are referring to are the sashes.  The majority of restoration work will be done on the sashes and not the actual window frame, sill or casing.
  2.  Parting Bead – this is the middle “guide” that runs up the middle between the lower and upper sash.  When we remove your sashes, this piece of the window is typically destroyed and must be replaced when we reinstall them.


Exterior Wood Window Diagram

Exterior Wood Window

The exterior diagram on your right shows you all of the parts to a wood window as seen from the outside.  We will discuss some of the most common terms we use when working on the exterior part of your windows.  Since this is the exterior view, the parts discussed in the interior view above remain the same (lower and upper sash, parting bead).

  1.  Stile – These are the left and right pieces of a sash.  These can suffer from mild to severe rot and may need to be replaced during restoration.
  2.  Rail – The top and bottom pieces of the sash.  The bottom rail is typically the one that must be replaced because it sets directly on the sill and if water gets caught underneath, the rail can literally all apart from rotting.
  3.  Muntin – Not only is this a fun word to say but it’s also the small divider that creates more beauty in your wood window.  Over time, these can become damaged or rot due to extreme condensation and lack of proper care.
  4.  Sill / Sub Sill–  Over the years, sills can lose the slight tilt they are originally built with and become flat.  When this happens, water cannot run off and gets trapped underneath the lower rail and rots out not only the sash but also the sill.


Exterior Wood Window Diagram

Do Your Wood Windows Need Help?

If your wood windows have any of the issues described above, we offer professional restoration and reproduction services to help get your wood windows looking and working amazing again.  You can click on the link below to read more about what Restor Wood Windows can do for you or simply fill out the form below to schedule a free consultation. 


We would be glad to come by your home to review the needs for your wood windows and provide you with a free estimate and timeline for when we can get started.

Give us a call or fill out the short online form to the right and one of our Restor Wood Window Specialists will contact you shortly to schedule a consultation.


Licensed and Insured

Choose all that apply

8 + 15 =