What’s wrong with my glass block? trader tricks

Website design By BotEap.comGlass block is a beautiful architectural detail, often found in bathrooms as windows or shower walls. It is a very durable and low maintenance product that diffuses light and adds value to any home. One of the best uses is as a window in a shower or over a bathtub, where privacy is essential, but light is desired.

Website design By BotEap.comI have installed thousands of windows and showers over the last seven years in Florida and have seen several puzzling occurrences. Let me reiterate that out of thousands of installations, I have only seen a handful of issues and have been able to easily fix them. The following are my favourites:

Website design By BotEap.comfog block

Website design By BotEap.comThis appears as an opaque or hard to see block, unlike those around it. Sometimes condensed moisture can be seen inside. The reason is simple. Glass block is formed by melting molten glass into two shapes, then sealing those two shapes together, creating a block. During the sealing process, the block is normally vacuum sealed, which prevents moisture from entering the block. Occasionally the seal is not complete or sometimes movement once installed will break the seal allowing air (and moisture) to enter the block. This moisture will eventually fog up and condense on the glass. The only solution is to remove and reattach the block, best done with a hammer and chisel (with eye protection) or even better, pick up the phone and hire a professional!

Website design By BotEap.comblack dots within black

Website design By BotEap.comAnother result of the sealing process is the occasional presence of ash within the vacuum sealed block. This resembles the black matter, and is no mold! This is harmless and the best solution is to ignore it! If it really bothers you, remove the block as above.

Website design By BotEap.comSpider lines on the inside of the block face

Website design By BotEap.comThese are birthmarks that result from the heating and cooling of the glass. The best solution in this case too is to ignore them or, if it really bothers you, remove them as directed.

Website design By BotEap.comLeaking grout joints

Website design By BotEap.comThis is a particularly troublesome occurrence, as you will no doubt experience water running down the block and sometimes puddled. There are several possibilities in this case.

• The first and most benign is that moisture in the air condenses on the window. Grout is a cementitious product, porous by nature. Although glass block mortar has a waterproofing agent present, sometimes moisture gets through the grout. If moisture is present regardless of rain or wind, and results in faint white streaks running down the glass, your problem is probably simple condensation. Buy a grout sealer and seal the grout on both sides of the window.
• The second possibility is a broken seal in the grout or a poorly mortared window (the joint may have mortar inside and out, but be empty in the middle, providing little material to block water from getting inside). This is often seen in cases of heavy rain or rain from a particular direction. Grout should be cut with a 4″ power grinder, filled with mortar and re-grouted. Seal as above.
• The third option and the most difficult to solve is that of a leak. elsewhere in the house, which is coming out through the porous joints of the glass block window. First of all, this leak must be detected, which can be done by visual inspection, a water test (with a hose that continuously sprays water on the side of the house), or a moisture meter. A good mold removal company can test the water and will have a moisture meter if you need help. Things to look for: Cracks in the stucco above the window. Void in stucco bands or joints above the window. Holes where two stucco beads or bands meet. Roof seams that are not flashed behind the stucco or sheathing material. A good home inspector can solve these problems. Note that this last issue has nothing to do with the glass block and must be resolved at the source of the leak.

Website design By BotEap.comMysterious cracked glass block

Website design By BotEap.comThis is my favorite, because it’s so unusual. You are asleep in the middle of the night and you hear glass breaking. You search the house and discover that your glass block window is broken. Or you go to take a shower and notice broken glass on the shower floor, only to find out that your glass block window is broken! As time passes, more and more cracks appear and the glass blocks break. I fixed a few of these before I realized what was going on (disclaimer, I didn’t do the original install!) The original installer decided to save a few bucks and forego using glass block panel anchors as instructed manufacturer. Instead, he used thick roofing straps. Eventually these straps rusted, causing them to expand at the mortar joint. Something had to give to accommodate the expansion. The mortar has high compressive strength and is dense in composition, so there was no room to spare. The only other option was glass, which eventually gave way under the ever-increasing pressure of the expanding metal. It’s amazing how rusty metal can break glass!

Website design By BotEap.comAs you proceed to resolve any of these issues, be careful! Removing the glass block is tedious and dangerous. Always wear eye protection and keep in mind that it is very difficult to remove a block without breaking the one next to it. Thoroughly clean all broken glass to prevent future damage. It would probably be worth hiring a professional to inspect or resolve any of these issues, as this goes beyond the basic home maintenance project.

Website design By BotEap.comDon’t let any of these problems stop you from using glass blocks. As you will notice, most of these problems can be avoided by using an experienced installer who follows the manufacturer’s instructions. If you can’t find someone in your area, feel free to email me and I’ll do my best to locate a qualified installer in your area.