A simple technique by Frank Caputo makes setting window stool a whole lot easier.

I’ve been working with my dad for 15 years. In those years, I’ve learned almost everything I know from him. But lately I’ve been picking up some great techniques from the JLC Forums, and they’ve changed the way we work. Yes, they’ve even changed my Dad’s approach to a craft he’s been practicing for over thirty years.

On a recent job, we were asked to install all of the window stool at the same elevation throughout the home, and tie together the stool on adjacent windows. I’ve done this same work before many times, using wooden shims. But that technique has always been frustrating.

Because the shims go in from the front, it’s easy to shim the front of the stool to exactly the elevation you want, but dialing in the rear surface of the stool—so it’s at exact the right elevation, which sometimes means tight up against the window sill—is next to impossible. And if you do manage to get the stool right where you want it, keeping it there is a bear—the stool often slips when you drive in fasteners.

Watching ONE video on the JLC website changed my whole approach to setting window stool. And I owe the whole technique to Frank Caputo. That’s why we have dubbed this technique installing Frank Screws. To see Frank’s video tip, click on this link.

The Frank Screw is a simple trim installation technique. While Frank demonstrated using a laser to set the screws, I only use the laser to check that all the windows are level and set at the same elevation. Then I use a gauge block (often a piece of the molding itself) to set the screws, driving the screw in deeper or backing it out until the top of the molding is at exactly the right elevation. It may sound too simple, but this trick saves us TONS of aggravation and speeds up our productivity on window trim and jamb installations. And trust me, there are many more places you will find to use a Frank Screw.

Continuous Stool

Recently I used this trick on a bank of Andersen Windows that came with supplied dado jambs (the extension jambs fit into a dado in the window frame). I wasn’t able to preassemble the extension frames with the trim attached, which is how I usually installed extension jambs. The trim on this job included tricky entablatures and the casing met in the corners, so we had to install the trim components one piece at a time.

On this job, we took care to install the windows perfectly level. All I needed to worry about was perfect reveal lines. And Frank Screws made that easy. In some places, the stool had to be scribed carefully to the walls, and the screws made it easy to dry fit each piece until it fit just right—without driving in even one temporary tack. I hate unnecessary nail holes!

Frank Screws came in handy especially because the stool was connected in many places.
I used a sample of the WindsorONE classical craftsman stool for my gauge block.

Since the stool is supposed to fit up tight to the interior flange of the window, setting these screws in positions was a piece of cake. I held the sample up in position along the sill flange, and then drove a screw right next to it. I adjusted the depth of each screw so that I could just barely slide the stool in between the top of the screw and the bottom of the sill flange. If the stool is installed separately from the frame, the screw can be left a little high because you can tip the stool into place.

But if the casing is already installed, don’t leave the screws too high or it’s tough to slide the stool in.

That’s it! In less than five minutes, I set three or four screws for each window and was ready to install the stool. Without using any shims, the stool came up tight against the bottoms of all the sills. The last step was driving fasteners up into the casing.

You can imagine how easy the installation was once the screws were installed.

Carpentry can be stressful, especially finish work. I’m always trying to make things perfect on imperfect jobsites. Frank Screws are one of those techniques I depend on to relieve the stress—I don’t have to worry about someone putting weight on the stool and ruining the reveals, I don’t have to spend hours on a job that I never have confidence in. Instead of a dreaded job, this entire installation was actually fun. And of course the windows turned out great.

Thank you Frank Caputo!