On this page:
- How Pros Estimate Glass Block Installation Projects
- Benefits of Glass Blocks
- Factors Affecting Cost
- What’s Involved with Glass Block Installation?
- Preparing for Glass Block Installation
- Cost Comparisons
- Level of Difficulty
- Find a Pro
Solid and protective, yet translucent and shiny -- those are some of the qualities of glass blocks. When used for windows they create privacy without sacrificing light, and they lend any bathroom an air of luxurious modernity when used as a barrier for a shower or tub enclosure.
Glass blocks are similar to bricks or cinder blocks when it comes to installing them, but the process is a little more painstaking and calls for more precision. Although it can be an interesting and satisfying DIY job, glass block installation is best left to pros with the proper tools and experience.
How Pros Estimate Glass Block Installation Projects
Basic Estimation Strategy
When providing a quote for a glass block installation, a pro has to consider the cost of the blocks and other necessary materials, the cost of building the frame, and the cost of installing the blocks themselves. There may be additional costs involved with preparing the space, construction of the frame, and installation of the blocks.
Cost of the Blocks
Glass blocks cost anywhere from $5 to $15 each, depending on size and quality. They are usually less expensive when you buy them in packs of three, eight or sixteen than when buying them individually. Specialty blocks, such as end pieces, tend to cost slightly more than conventional square or rectangular ones.
Some frames consist of nothing more than a bottom track secured to the floor to which the blocks can be affixed. In some cases -- such as when blocks are being installed in a window or outside -- installers have to build a complete perimeter frame.
Installers usually charge on a per-block basis, which depends on the size of the blocks and the scope of the job in general. The rate can vary from $8 to $20 a block, with the average rate being somewhere from $10 to $12 per block. The installation rate usually includes setting the blocks in mortar and sealing them after the mortar has set.
Benefits of Glass Blocks
One of the main reasons people choose glass blocks to frame shower stalls or create partitions in living rooms is because of the appeal of their slick and polished elegance. Glass blocks have been around since the 1930s and, since that time, have remained a perennial favorite of avant garde interior designers looking for alternatives to ceramic tiles.
Although they allow sparkles of light to pass, glass blocks are translucent -- not transparent -- and they provide plenty of visual privacy. Although they are made from a seemingly fragile material, they are surprisingly durable, and a wall or window made from glass blocks is highly resistant to stress and impacts. It’s important to remember that glass blocks aren’t strong enough to support loads and aren’t suitable for bearing walls.
The process by which glass blocks are manufactured creates a partial vacuum inside each block which impedes heat transfer. This makes glass blocks an energy-saving alternative to plate glass for windows when they are properly mortared and sealed. Moreover, because the blocks are translucent, they allow warmth from the sun to penetrate.
Factors Affecting Cost
Design and Materials
Because there is such a large price variation between conventional and top-quality ones, the choice of blocks is one of the main determinants of the cost of a large glass block project. The design of the installation is also a factor. For example a curved wall requires careful layout, and laying the blocks requires skill, so it costs more than a straight wall.
Scope of the Job
The size of the job affects the number of blocks you need to buy as well as the time it takes to install them. Some smaller jobs, such as basement window installations, can get pricey if they require a fair amount of demolition and preparation before the blocks can be installed.
Because installing glass blocks requires a fair amount of skill, there is a significant variation in rates charged by pros who do it. An experienced pro with good references can charge more than someone new to the trade, and if quality is important to you, it’s worth it to pay the higher rate. It’s possible to undertake the installation yourself and save the contractor cost, but you need plenty of patience and a good set of working instructions.
What’s Involved with Glass Block Installation?
Most glass block projects require a frame -- or at least a partial one -- to hold the blocks. The frame often includes a rubber or plastic channel designed to fit around the blocks and prevent them from moving until the mortar has a chance to set.
Layout and Dry Fit
Unlike bricks, you can’t cut glass blocks into smaller sections, so the layout of your project must be carefully planned before you start setting the blocks. Once the blocks are on site and the frame is prepared, most installers dry fit the blocks to make sure they fit in the space and to fine tune the frame.
Setting the Blocks
Installers typically use mortar to hold the blocks together. The mortar usually reinforced with strands of wire to prevent cracking. Spacers are used to keep the blocks a uniform distance apart. When building a wall, block setters check with a spirit level to ensure the wall is plumb and level.
Sealing the Blocks
The final step in installation is to seal the edges of the blocks with silicone sealant. This is an especially important step when building a shower enclosure or setting blocks in an exterior window. Installers usually have to return to the project a few days after setting the blocks to apply the sealant.
Preparing for Glass Block Installation
Take Careful Measurements
Whether you’re building a wall or installing glass blocks in a window, you need the exact dimensions of the project to allow you to buy the right number of blocks of the appropriate size. If you’re hiring a pro to do the job, the pro will need the dimensions to prepare an accurate quote.
Nothing is worse than discovering the exact style of block you wanted at a price that fits your budget the day after you’ve completed the project with a second-choice product. Avoid buyer’s regret by carefully comparing options online and at local building outlets before making a purchase.
Get More than One Quote
There is usually more than one way to complete a glass block installation, and getting quotes from different contractors is a good way to explore options. It’s also a good way to make sure you get the best price and the best quality workmanship.
|$75 - $1,000||$360 - $2,160||$480 - $2,800|
Costs for large and small projects vary according to block size and quality, as well as labor rates and other factors.
Windows: $75 - $1,000
- • Project Size: Window installations usually cover a small area that can be covered with 8 to 20 blocks.
- • Block Quality: You can choose from standard blocks to thicker, energy-efficient ones. You can even buy pre-assembled glass block windows that you simply install in the window frame.
- • Labor Costs: Save on contractor fees by doing the installation yourself. If you hire an installer, you’ll probably pay a rate from $10 to $15 per block.
Interior/Exterior Partition Walls: $360 - $2,160
- • Project Size: Size of project varies from 16 to 80 square feet. Larger projects require more blocks and more installation time, so they understandably cost more than smaller ones.
- • Block Quality: Budget-conscious homeowners may stick with less expensive blocks costing $5 each while more extravagant ones may opt for top-of-the-line blocks costing $15 each.
- • Labor Costs: Professional installation is recommended. For non-designer projects, it typically costs $10 to $12 per block.
Designer Projects: $480 - $2,800
- • Project Size: The cost of designer projects, like that of standard interior/exterior wall partitions, varies with the size of the project. A 16 square-foot project requires more blocks and labor than an 80-square-foot project.
- • Block Quality: Typically, only top-quality blocks, costing $15 or more per block, are used for designer projects.
- • Labor Costs: Because precision is more important in a designer project, you may have to pay an installation rate from $15 to $20 per block. Designer projects may involve complications, such as a curved base, that also raise the installation costs.
Level of Difficulty
Glass block installation requires patience and precision; if you approximate measurements, hurry block placement or mix mortar to an unsuitable consistency, both the appearance and stability of your project will probably suffer. Smaller projects, such as windows and low exterior walls, may be suitable for homeowners, but large walls, partitions and designer projects should be left to pros with specific experience in glass block installation.
Glass Block Installation Services
When choosing a pro for glass block installation, it’s best to consult with more than one before making your selection. Glass block installation is a specialty trade, and you want to make sure the person who does your job has the requisite experience and references. With this in mind, remember that when two or more bids are on the table, the lowest one isn’t necessarily the best one.