Let the sunshine light up your dark spaces
Glass block windows are an excellent addition to any home, providing both aesthetic appeal and practical functionality. These windows offer privacy, security, and natural light while adding a unique touch to your living space. If you want to know how to install a glass block window, this illuminating, step-by-step guide will walk you through the process.
Glass block windows can work in any room in your home—for example, they’re a great kitchen window idea. However, they shine in bathrooms and basements where privacy is a priority. Glass block windows allow natural light to filter through while obscuring the view from the other side.
These windows offer more perks. They boost security due to their solid construction, making it difficult for intruders to break in. This is also why they resist extreme weather conditions, reducing the risk of damage and ensuring durability. Non-vented glass block windows enhance energy efficiently because they don’t leak air. They also muffle noise if you want a window with enhanced soundproofing.
All the benefits of glass block windows make them an ideal choice for people looking to elevate their living spaces' functionality and aesthetic appeal.
A glass block window's cost varies depending on size, design, and installation requirements. However, glass block windows are a more budget-friendly option compared to triple-pane window costs, which can be as high as $3,000, including labor. On the flip side, a glass block window installation typically tops off at around $1,500 for all the materials and a professional installation. You can save a bit of money if you DIY.
You will find glass block windows at home improvement stores starting at around $70 for a 31-by-13-inch non-vented glass block window. Larger sizes and other types of glass block windows, for instance, vented and casements, can go as high as $800.
First, an important heads up: Please consult your local building inspector before starting this project, as specific building codes may mandate the inclusion of ventilation in basement and bathroom windows.
Additionally, take your skill level into consideration before starting. This project requires careful measurements, the ability to lift heavy glass panes, and intermediate masonry skills. If you don’t feel confident about your ability to do any one of these things, let a pro handle it, as any small mistake could lead to costly damages down the road.
Now that you’ve talked to a building inspector and reflected on your DIY skills, you will need to determine the size of the glass block window panel you need. Measure your window from inside the jambs, and subtract 1/2 inch from the length and width of the opening for your window. This will provide ample room for the curb you need to construct underneath the window panel using mortar. (Also, the resulting gaps on the sides will be filled with mortar, so there’s no need to fret about any excess space.)
Afterward, purchase your pre-assembled or custom-order window at your local home improvement store.
Wear eye protection and work gloves for this next step to prevent injury from broken glass or other materials. Use a wrecking bar to carefully pry out the old window jamb (the sides creating the frame). Cut the wood sill using a handsaw or circular saw while being cautious not to cut through the concrete or supporting wall.
Afterward, remove the sill, side jambs, and head jamb. You may need a utility knife to remove the old caulk and paint. Confused about all the different parts of a window? It might be time to put down the saw and call a pro.
You should fasten a wooden block temporarily beneath the sill plate using screws. It will prevent the glass block window from slipping during installation. You will want to ensure that the block extends downward sufficiently to prevent the glass block window panel from tipping inward. If your home lacks a sill plate, simply attach the block to a joist instead.
Grab a helper for this next step. One person will be outside the window opening. The other will be inside.
Place the bottom of the window on two wood wedges from the exterior side. The bottom of the window will slide inward a bit. Your helper inside and the block will help stabilize the window during the positioning process.
Now that the window is in position, it’s time to ensure that it’s level and centered. To accomplish this, use your level and adjust the wedges. You can use wood shims for further adjustments and to secure the window. Ensure your helper is on the other side of the window in case of slippage.
Afterward, measure the distance from the center of the window to each of the four corners to ensure it is centered, or square. You may need to adjust the wedges and shims to secure the window. Then, check your work using your level once again.
First, gather the necessary materials, including mortar mix, a bucket, water, trowels, a drill, a scoop, and a grout mixing paddle. You must also wear your work gloves because mortar can harm the skin.
Next, measure the mortar mix using the scoop and add it to the bucket based on the manufacturer's instructions. Afterward, add water gradually, pouring it into the bucket while continuously stirring it with a trowel.
It is essential to mix the mortar thoroughly until it becomes one consistent mixture, ensuring no dry or lumpy areas are left behind, just like you would with pancake batter. Grab your drill and pop on the grout-mixing paddle to get the job done.
When the mixing is complete, let the mortar rest to activate the bonding agents for better workability. It should take up to 15 minutes. Making small batches of mortar is a good idea to avoid waste throughout the project.
From the exterior side of the window, fill the gaps under and alongside the glass block window panel with mortar, ensuring a thorough packing. Begin by packing the bottom and smoothing the curb where the window sits, avoiding contact with the wedges and shims. Allow the curb to harden to the touch before moving on to the sides. This will enable you to brush off any mortar crumbs that may have fallen onto the curb.
Next, fill in the sides, avoiding any additional wedges and shims.
Then, use a margin trowel and a pointing trowel to fill in any additional gaps alongside the panel. Once the mortar has stiffened slightly, use one of your trowels to smooth things.
Once the curb for the glass block window panel sets, remove the wedges and shims. Remember that the mortar must be properly set and hardened before performing this step. It is a good idea to refer to the mortar manufacturer's instructions for timing. As a rule of thumb, the mortar will require at least two hours to set or up to five hours in cooler temps.
Carefully fill the gaps that the wedges and shims have created with mortar. Once the mortar is stiff, you can smooth it out with a trowel. Afterward, you must wait several hours for the mortar to completely dry and set.
Now, ensure a watertight seal from the window's exterior and interior sides with weather-resistant caulk. You must apply it to the gaps or seams between the glass block window panel and the wall. Don't skip this step because it is crucial for keeping unwanted moisture out.
Grab your trusty tube of weather-resistant silicone caulk and place it into your caulking gun. Carefully apply the caulk along the entire perimeter. Take your time to ensure a thorough and even application, leaving no room for water infiltration or pesky drafts.
Now you can stand back and enjoy the natural light.
As you can see, this isn’t as complicated of a project as, say, installing a bow window. However, glass block windows are pretty heavy, and incorrect installation could cost you a lot more than the initial price of the glass block window or even labor and installation costs if you hire out. Working with a local window contractor will undoubtedly lighten the load and is the safer bet.
If you want to increase the DIYability of this project, you can consider acrylic block windows, instead. They are considerably lighter, but don’t expect a considerable saving. They typically cost the same as glass. Additionally, acrylic scratches easily and can turn yellow from long-term sun exposure.
With proper installation and maintenance, glass block windows can last for several decades. On average, you can expect glass block windows to have a life span of 15 to 30 years or more. The actual life span depends on various factors, such as the quality of the blocks, the installation technique, exposure to harsh weather conditions, and regular maintenance.
Yes, glass block windows do require some maintenance. While they are generally low-maintenance compared to other window types, regular cleaning is necessary to keep them looking their best. Dirt, dust, and muck can accumulate on the surface, reducing the amount of light they let in and their visual appeal. If you see any cracks or gaps, promptly repair them to prevent water leakage and maintain the window's integrity. By performing these simple maintenance tasks, you can prolong the lifespan and functionality of your glass block windows.
Glass block windows come in various patterns and styles that offer privacy and unique aesthetics. Frosted or textured glass diffuses light and enhances privacy. Wave-pattern glass blocks imitate ocean waves with flowing lines. Ice-glass blocks resemble cracked ice. Fluted glass blocks feature parallel vertical grooves, adding texture and depth. Clear glass blocks, similar to glass Coke bottles, offer transparency with some distortion and may have smooth surfaces or subtle textures, adding visual interest.
