How to Repair Bow Windows

What You'll Need
Support brackets
Cables and screws
Cable tighteners

If your home has bow windows on the front of your house, you may notice that they can become saggy or deformed after a while. Unlike bay windows, their relatives, the bow window is not supported by the foundations, nor built up as part of the house. Instead, they are more like picture windows that are curved away from the front wall. These windows may have a curved window sill or seat beneath them, but they will be hung from the wall and not supported. In order to repair a sagging bow window, you must first understand the causes of it, and then follow a few simple steps to fixing it.

Step 1 - Understanding the Bow

Before you begin fixing the bow, you must first understand why the damage has happened. Bow windows are vulnerable to gravity, so if they are not supported properly at the top and bottom, they will experience some sagging. Work out where the sagging is coming from before attempting to create a fix. If it seems like the bottom of the bow is the cause of the sagging, then you will need to insert some support brackets, but if the roof is buckling, then you will need some stronger support for your bow window.

Step 2 - Fitting Support Brackets

Your bow window can be supported by fitting support brackets under the base. These brackets look like small L shapes, with the middle of the L thickened, so that the weight is spread evenly along both branches of the shape. Take the first bracket, and fit below the bottom of the window. Push the bracket upwards, so that the window is actually lifted a little, particularly at the place where sagging has occurred. You should then screw the bracket into the wall, so that the weight is distributed from the bracket onto the foundation of the house. Place three or more brackets in spaced evenly apart. The more brackets you install, the more support you will give to your bow window.

Step 3 - Fitting a Support Cable

A support cable takes some of the weight from your bow window, and distributes it down the walls into the foundation. First, fit a bracket to the center top of the window. You can then install your cable kit onto the wall. Your kit should contain the cable, and the means to screw it tightly to the wall. Keep the cable as taut as possible while you are threading it through the bracket hole. Wrap the cable around the bracket, and then use the cable tightener to make the cable as supportive as possible.

The cable should tighten so that it partially lifts the sag from the window. You should fit the cable carefully, and make sure that you don't tighten it so much that the cable snaps. You may wish to fit a pair of cables, so that each takes half the support of the bow window, as this can ensure that no one cable is supporting the whole of the window.