4 Easy Steps to Repair Broken Windows in Your Greenhouse or Garden Shed


You may have a beautifully and elegantly built garden shed or even greenhouse that provides a superb landscape to your home but if you’re not careful about its upkeep, this aesthetic value might as well be diminished. Unfortunately, accidents do occur. Strong winds can send projectiles to your shed or greenhouse shattering your windows. A stray football or even baseball can also break the glass in this part of your property. But, you clearly don’t have to worry as applying a quick fix is a lot easier compared to the repairs you’d have to consider in other parts of your home.

However easy the repairs are, the lack or low levels of confidence can sometimes make the whole endeavor very challenging. In such cases, you can always seek the services of a professional shed windows repair specialist to initiate the fixing of your broken windows. Alternatively, you can purchase from them a polycarbonate window replacement that is guaranteed to be vandal-proof. You can then remove the glass shards, clean up everything, and mount this replacement. Instead of applying a putty, you can use a silicone filler to bond the polycarbonate onto the window frame. Just make sure to use a quick-fixing type of silicone adhesive filler. The good thing about this option is that you can make specific requests as to the actual size or dimensions of the window panel that you need.

When done correctly, you can actually finish your repairs within the day. Of course, you’ll need a trip to your favorite hardware supplier, purchase all the materials you’ll need, and find motivation and encouragement from the rest of your family.

Here are the 4 steps you’ll need for an easy repair of broken windows in your greenhouse or garden shed.

1.       Prepare Your Materials 

As in any do it yourself repairs, it is essential to make sure that you have all of the things that you will need. For this project you will need the following materials: 

  • A putty knife; in case you don’t have one, you can use an old butter knife
  • Heavy-duty leather work gloves
  • Measuring tape
  • New window glass
  • Razor blade
  • Small tacks or glaze points
  • Sufficient amount of putty 

Sometimes, it is also advisable to wear the correct work clothes, preferably long sleeved shirts as shards of glass may inadvertently fall on your skin. You don’t want to turn your DIY project into a nightmare where you’ll be landing in the emergency room and coming out of it with a few stitches and several shots of anti-tetanus. Likewise, you may need to wear goggles to protect your eyes. While these are not absolute necessities, they can protect you from injuries if in any case accidents occur. It is also advisable to get some pieces of old newspaper to line your work area. The whole point in working on a home project, be it repairs or renovations, is for you to think of safety always.

2.       Prepare Your Windows 

Once you have assembled everything that you need, you can start with the very first step in garden shed window repair: removing the broken glass. This is one of the trickiest parts since you will be handling shards of glass which, if you’re not careful, can cut you deep. That’s why you will need to don the thickest leather work gloves you can find. It is essential that it should allow you freedom of movement, however; otherwise, limiting your hand and finger movements can also increase your risk of injuries as you may not be able to hold the glass shards very well. In removing shards, work your way from the largest pieces before tackling the smaller ones.  

In case you cannot dislodge the broken glass from the frame, you may have to apply duct tape on the outside of the window pane and make sure that all shards have been covered by the tape. Wear your safety goggles and try to hammer carefully the glass from the window frame. Alternatively, you can use a strip of lumber to smash through the window. That is why it is a must that you wear your goggles plus a pair of thick leather work gloves for this. 

After removing all of the glass from your broken window, it’s now time to work on the putty or the trim. With your putty knife or, if you don’t have a putty knife, an old butter knife, slowly and meticulously loosen existing putty. Make sure to be careful in the removal process as there is a tendency that smaller glass shards may still be present in the frame. Remove any glass that remains and dispose of in the appropriate receptacle. Be thorough in the removal of the old putty as you’ll be applying a new layer. In case your garden shed window has trimmings, be careful when removing these. Make sure you don’t damage these as you’re going to remount them later on.  

If there are still putty that remains in the window frame even after thorough scraping with the putty knife, use a razor blade to scrape off the remaining putty bits. Be careful when handling the razor as you may cut yourself in the process. It is sometimes a lot better to shave off these layers bit by bit rather than scraping them in one complete motion. Additionally, make sure that you have completely removed or pulled out old glazing points that may be present in your garden shed window frame.  

The whole idea about preparing your window is to make sure you have a very smooth and even surface for the attachment of the new replacement glass and the application of new putty. If not, you are only undermining the structural integrity of your newly installed glass window. 

3.       Install Your New Glass 

By the time you have completed the preparation of your window, you’re halfway there. First, you will have to determine the size of your window frame so you can cut it just right. Get your tape measure and determine the dimensions of the putty-less and glass-less window frame. It is very important to get a very accurate measurement as fitting an incorrect size of glass can have disastrous consequences. You can get someone else to do another measurement and then compare both measurements. If both of you have the same results, then you have taken an accurate measurement. If not, you’d have to do it again. If you don’t have anyone to compare measurements with, you can take at least two measurements for comparison.  

While you can safely cut your glass using the correct tools, if you’re not really confident about it, it is best to seek the services of a professional glass cutter. You can bring your measurements to your local hardware and they can cut it for you. However, if your window frame happens to have a standard design and dimension, you may already have a pre-cut glass available at the hardware store. One quick advice: if you live in a place where there is a great variation in environmental temperatures, you must cut your glass about an eighth of an inch narrower and shorter than the actual measurements. For instance, if you measured 15 inches by 36 inches, then the final measurement of the cut size should be 14-7/8 inches by 35-7/8 inches. The reason for this is to allow your glass to expand during the hot weather without necessarily cracking through the putty.  

Once you have your glass ready, apply a generous amount of putty into the borders of the window frame. Meticulously apply just the right amounts of putty and in an even application, not globs of putty in different sections. What you want to achieve is uniformity in the application of the putty. This also means there should be no gaps nor spaces in the putty. If you’re going to look at the window frame, you will have one continuous putty on the frame of your window. 

Gently place the glass squarely on the putty lining. Gently press the glass so that it will not fall even when you have already removed your hand off the glass. To help secure the glass, you can put small tacks or glazer points along the side of the window frame. The ideal setup is for the glazer points to sit squarely in the frame and serve as the glass’ sturdy buttresses. You can put around 2 to 3 glazer points on each side of the window frame, although you can put more depending on the size or dimension of your glass. Don’t apply pressure directly on the glass when putting glazer points. Aim for the frame instead.  

4.       Finish Your Installation 

After installing your glass pane onto the bed of putty lining and putting glazer points or small tacks to help secure it in place, you can now start finishing your project. Before applying the final layer of putty, make sure you are satisfied with the placement of the glass and that it is no longer moving from its putty bed. You can then apply an additional layer of putty, making sure that it is even along the entire length of the window frame. With your putty knife or an improvised spatula, you can start reshaping the outer putty layer with a 45-degree slope. This will help protect the inner junction of the glass embedded in the putty from condensation as well as rain water. Additionally, the 45-degree slope will help redirect moisture away from the window frame. 

Remove any putty debris. Make sure to run the straight edge of your putty knife along the putty layer to make for a very smooth and even surface. If at all possible, gently compress the putty so that it forms a very tight seal on the glass underneath it. Allow the putty to dry overnight, if not a full 24 hours, to make sure that the putty has completely dried before making any attempts at touching it.

And you’re done. The good news is that this particular project is not really difficult. As long as you observe basic safety protocols, obtain all of the materials and tools you’ll need for the project, and follow these four very simple steps, you can change or replace that broken window in your greenhouse or garden shed.

But here’s the thing. If you don’t feel confident about any of these steps in the repair of your garden shed window, it is still best to seek the services of a window repair service. Sure, you’ll be paying for their services but, you’ll be simply relaxing right inside your home while they work to fix your window. There’s no more worrying about whether you’re doing the procedure right or not. The decision is still yours to make, nevertheless.