# Installing glass block: Silicone or mortar?



## jomama45 (Nov 13, 2008)

I've never been a fan of the silicone approach myself. The mortar is superior in every way as far as I know, other than it's a little more labor intensive.

I would try to assemble the panel close to the opening with glass block mortar and install as one unit. I typically buy our units pre-built from a supplier, and the only difference is that they have metal banding around the perimeter for transport reasons.


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## stglassblock (Sep 15, 2010)

*Silicone...for sure!*

when installing glass block windows and want longevity, silicone is the way to go! it is mildew resistant, doesnt chip, crack, shrink, fade as the mortar will. although the mortar used for glass block does have silicone additives, you still risk the issues mentioned above. There are several silicones on the market for glass block. NOT ALL ARE EQUAL! 
They also make perimeter frames that seal to the house as a regular windows do, that you would lay the block in. I would always recommend using a perimeter frame for a window. by doing so, you can flash the window properly. Not sure why you would be using vinegar to clean the block, unless it is used..? you can also have a prebuilt window made to your specifications.


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## WJMC (Jan 10, 2011)

*Silicone is proven to be more forgiving*

I support silicone, it will give and recover much better then mortar. Once you break the mortar, you loose the strength that supports the wall, but with a proper silicone, it will take an impact and recover to its original form. To break the bond you would basically have to break the blocks and even by doing this, the areas that were siliconed would still be intact. The two most versitile sylicone systems that come to mind are Swift Track and Vinyl Wrap. So do your homework and don't be afraid of installing glass blocks with silicone. Systems will help....



boru said:


> I'm about to replace basement windows with reclaimed glass blocks. Never worked with them before. I will clean them today with vinegar and XXXX steel wool. Then, I've been told to first create the 13x24" assembly of blocks with silicone, then mortar in that assembly. I've also been told to never to use silicone -- only use mortar, butter and put in the blocks one at a time.
> I'd rather pre-assemble using silicone -- but what are the risks? Is this simply a matter of preference, or is one a best practice for a reason?


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## stglassblock (Sep 15, 2010)

There are several silicone systems on the market. Not all are equal. When using the recommended perimeter frame, you want to use a frame that doesnt cover the edges of the block. When you view the window, you want to see ALL the block..not covered up by frame in my opinion. In addition there are several colors of frame with nailing flange to choose from that will match your existing windows such as TAN (AKA..adobe, clay) ALMOND (AKA..creamy off white color) WHITE, BRONZE(AKA deep brown color) and even MILL FINISH! These are all available through a silicone system and are very durable, strong, non pourous and long lasting!


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## GB Greg (Oct 14, 2010)

We're replacing basement windows folks. Not prime windows. You do not need the expense of the framed windows. We manufacture a line we ship coast to coast. These windows are a "new construction" window meant to be installed in wood framing like prime windows.

Silicone or mortar. Each has its benefits and in the case of a basement window replacement, it quite simply comes down to how you want your basement windows to look. 

For a DIYer, silicone is going to be the easiest to assemble and install. Mortar, unless you're a mason by trade or have experience with it, is going to be a nightmare!

We assemble mortar or silicone at the customer's request. All basement windows would be installed with mortar between the window and the foundation. Remove the existing frames entirely....

As far as cleaning your reclaimed blocks, steel wool or a bench grinder with a brass wheel is all you need. You shouldn't have to use any chemicals to remove what mortar or silicone may exist.


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