Expert: Jamie Yocono - 10/31/2005

Question
We have a bathroom window we are wanting to place glass blocks in. The glass blocks are a little bit bigger than our current window. We have brick on the outside and ceramic tile on the inside. Can we cut the tile and brick to match the window size we need? If so, what tool do we need?

Answer
Hi Kevin,

Normally, I wouldn't attempt to answer a questions about glass block, since my area of expertise is woodworking.

However, just this past summer, I did a HUGE glass block project on my home. I laid nearly 1000 solar glass block, and I learned a lot about what to do and what NOT to do. So I will try to help you out.

First off- your question is about cutting your existing rough opening to fit the glass block. I can't give you much information about cutting brick or tile, other than recommending the use of a masonry blade in a hand held circular saw. It will be messy and make a ton of dust, but you definitely can cut brick and tile with this sort of blade. If you absolutely have to cut the opening wider, what I would recommend is cutting the perimeter of the opening with your masonry blade, and then using a stone chisel and hammer to get the rest of the material out of there. Scoring it will give you a nice clean edge, but I doubt your blade will go all the way through the brick, so you will have to do some hand clean up with your chisel.

BUT....this is important..... before you do any cutting of anything... measure the exact dimensions of the glass block. On the paper work that I had regarding the glass block, it said that the block measured 8" x 8". And based on that, I framed in my rough opening using 8" block and 3/8" grout lines. When I had the opening all framed in and started laying my glass block in place, I discovered that the opening was about 2" too big. The block were actually smaller than I thought they were.

So here's my biggest piece of advice. Take a tape measure and go to the store where you're going to buy the block, and lay them all on the floor, measuring them with spaces in between them simulating the grout lines. I think you will be pleasantly surprised to find that they're actually smaller than the literature says.

Second bit of advice- the blocks most people buy are made by Pittsburgh-Corning. And they make a video about how to lay glass block. I bought my video at Lowes for about $7. I watched it 3 times, as those darn mortar spacers are really tough to get the hang of. So buy the video if you can, it will show you how to cut the spacers easily. In fact, I just sold my used video on eBay for about $13. Go figure. :)  Heck - you can buy the video, watch it a few times, and sell it like I did.

OK, that's the best I can do. Remember- I'm a woodworker, not a glass block expert, so I did the best I could to help you. There are probably a few experts here that can answer your question better than I can. In fact - I know there are, since I wrote to one of them a while ago for some advice before I started my glass block job.

Good luck, I hope this helps. Feel free to write back with any other questions you might have after reading this.

Jamie Yocono
Wood It Is! Custom Cabinetry
www.wooditis.com
Las Vegas, NV