My Florida home was built in the late 1950's and has the original jalousie windows. The house gets a bit warm inside on summer evenings when it doesn't rain. The central AC system was serviced two months ago and I was told it's working fine. I have a low-slope roof with no real attic.

A representative from the power company came to do an energy check. He said that many of the windows would not close all the way and suggested screwing them shut to keep the cold air in (or to buy new windows, but this is a cheaper fix). According to him this is a not uncommon thing to do on older homes here, but I haven't been able to find anything about it on the web.

I never open the windows and wouldn't mind permanently sealing them. I estimate the bottom corner metal is about 1/16 to 1/8 inch thick. Is it possible to do this, and if so, what kind of screws and tools would I need?

Closed window left side

Open window left side

Open window edge


  • I'm having a hard time telling from your ultra-closeups what needs to happen. How about a wider shot with some context?
    – isherwood
    Jun 15, 2021 at 18:34
  • Is that a concrete wall?
    – isherwood
    Jun 15, 2021 at 18:35
  • 1
    Those pics don't seem to depict what I know as a jalousie window (aka louver window). Jun 15, 2021 at 23:05
  • @isherwood Added a picture. I believe the walls are concrete block. Jun 16, 2021 at 13:47
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    Before making any sort of (semi-)permanent change to fix these in a closed position, please consider emergency egress! While those are small panes of glass, in case of a fire where your only exit is through the window, I'm sure that the enthusiasm of the situation would get you out. Anything that slows down and hinders that process could lead to loss of life. Please give it a good, solid mulling over, especially for bedroom windows.
    – FreeMan
    Jun 16, 2021 at 15:06

2 Answers 2


Screwing shut a jalousie window is decidedly quick-and-dirty — the result will appear dilapidated while semi-permanently defeating the function of the windows (possibly jamming window operators by cranking mechanical components). On the other hand, it's easy, cheap, and possibly effective.

How to screw down jalousie windows

We can screw plywood onto the edges to press down the windows that won't close. The metal siding on the edges of the jalousie window is likely aluminum, easily penetrated by general purpose drill bits.

Tools Needed

  1. handsaw
  2. screwdriver
  3. measuring tape
  4. pencil
  5. drill
  6. general purpose drill bits

Opt for 3/8 inch or 1/4 inch standard spruce plywood on the external face of the window. Thicker plywood will be more conspicuous. Quarter inch plywood

Non-tapered head screws will push down the plywood better than tapered or bulge-head screws, but ultimately any kind of exterior wood screws will work. I circled those I think would work best:Different kinds of wood screws

Use four, narrow pieces of plywood arranged in a frame-like rectangle measured to the width and height dimensions of the target window.

plywood frame made with four pieces of narrow wood pre-drilled with paper template

You can prepare holes in the window and the plywood frame using a strip of paper as a drilling template. If the window is not square (width is not the same as height), you'll need a template for the sides and a separate template for the top and bottom.

Draw lines at the top and bottom of the window, then choose where the screw holes will go by drawing the intended hole marks on the template. Align the top/bottom of your template with your plywood frame so that the holes on the plywood will line-up with the window's holes, then drill the same hole spacings on the plywood.

Positioning the plywood frame on top of the window

Consider fixing jalousie windows

If you are repairing your own home, semi-permanently disabling the windows (making them even more difficult to replace) could negatively affect your resell value. Window mechanisms also deserve better!

This is why, if you have the time and the tools (and skills), you might consider fixing or restoring the windows so they close properly. The fix might be as easy as putting a little WD40 in the window operator mechanism or it might require a more careful approach.

Cannedhamtrailers.com shows how to restore jalousie windows in this video: Restoring A Jalousie Window

Also, a FamilyHandyman.com article suggests several diagnostic steps to identify the problem precisely: How to Repair Jalousie Windows

  • This is a very thorough answer! I have to ask, though, why you recommend the horizontal pieces of plywood, instead of just vertical. The vertical pieces should be sufficient to hold the flopping bottom edges in place, I'd think.
    – FreeMan
    Jun 16, 2021 at 15:04
  • @FreeMan You're right. I thought about that, but I wasn't sure if the jalousie windows were vertical or horizontal from the pictures and it wasn't clear where they were refusing to close. OP may only need plywood strips of an orientation orthogonal to the direction of his/her windows (horizontal jalousie windows should only need vertical wood binding and vice versa for the vertical windows). However, I wanted to give the broadest answer possible with few conditional cases. Jun 16, 2021 at 22:01

I once bought a home in which some DIY genius had nailed windows shut. I hate him.
Do not under any circumstances foul up your windows that way. If they are truly that warped, then you're gonna have to replace them (heck, you will be lucky if screwing the frame down doesn't shatter the glass). If they aren't warped, Get some foam-strip insulation and apply that to the inside edges of the frame. Pick out a thickness sufficient to cover whatever gaps you have.

If you screw or nail the frames I will make sure all subsequent owners know who you are and where you are (not really but you get my point).

One other thing - take some time to clean all around the frame, especially near the hinges, to make sure it isn't just dirt that is preventing a good closing seal.

  • 1
    Screwing isn't quite the same as nailing. One's fairly easily reversible.
    – isherwood
    Jun 15, 2021 at 19:17
  • I would add that even if OP goes against this advice and screws the windows shut, insulation/weatherstrip at the window edge is still a good idea to help prevent gaps. Jun 16, 2021 at 15:34
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    I accepted Mavaddat's answer because it does (thoroughly) answer the actual question, but you're not wrong, and I'm not going to screw them shut. Jun 16, 2021 at 19:39

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