How to Replace a Damaged Glass Window Block

What You'll Need
Protective goggles
Work gloves
Long sleeved t-shirt and pants
Heavy duty duct tape
Glass block
Waste bin
Rubber mallet
Striking tool
Pre-mix mortar

When a glass window block gets cracked, scratched, or breaks, it diminishes the look of the entire window. If this happens to a window in your home, you do not have to re-do the entire window. This article will show you how to replace a damaged glass window block. Here is a list of what you will need to complete this project.

1. Preparation

Cover the damaged glass window block with strips of heavy duty duct tape. Then place a waste bin near the area you are working in. You may also wish to cover the floor with plastic in case any glass shards escape the tape.

Put on your protective gear. For this project you should wear goggles, work gloves, a long sleeved t-shirt, and thick pants. Even though you are covering the glass window block with tape, some glass may escape and you could get injured.

2. Remove Damaged Glass Window Blocks

Using your rubber mallet, strike one side of the glass block until you hear and feel the glass break. Then strike the other side of the block. Pull out the duct tape and any glass and throw it all in the waste bin. Most of the glass should have stayed stuck to the tape. Use a vacuum cleaner to clean up any shards or slivers that escaped.

3. Remove Old Mortar

Gently chip out the old mortar where the damaged glass window block was with a hammer and a chisel. Take care not to angle the chisel towards the adjoining blocks. If you crack or chip more blocks, you will have to remove and replace them as well.

4. Mix Mortar

Mix some pre-mix mortar in a bucket with water. Follow the instructions on the package to get the mortar to the proper consistency. For this project, you want the mortar to be the consistency of bread dough.

5. Putting in the New Glass Block

With a trowel, spread a layer of mortar on the bottom surface where the new glass window block is going in. The thickness of the mortar needs to match the mortar in the surrounding joints. Next, carefully slide a glass window block into the opening and center it. Then pack mortar into the spaces on the three other sides of the glass block and completely fill the joints. Do this on both sides of the window.

6. Finishing Touches

In about 2 hours, the mortar will get firm. When that happens, use a striking tool to compress and smooth the mortar joints. This will give your joints a clean and professional look and help the new block blend in with the rest of the window. Then, all that remains to do is to take a damp soft cloth and wipe the glass window blocks free of excess mortar.