The Cap Bead

How one simple, but tricky caulking bead can extend the life of your window and window wall systems and save you from a costly window replacement project.

If you’ve ever experienced leaking windows or windows with a draft, you have received the exorbitant quote from a contractor to replace the glass. Here’s the thing, there’s nothing wrong with your glass. As long as you don’t see condensation in between the two panes of an Insulated Glass Unit (IGU), the problem isn’t the glass. The real issue is the deterioration of the butyl tape that seals your glass from the exterior weather conditions. What the contractor can do is bill you for removing the glass, removing, and cleaning the old butyl tape, and installing glass again. Again, costly. ArmourCo Solutions has you and your yearly budget covered. The cap bead.

 

What is it?

The cap bead, a specialty caulking bead, bridges the gap between the window frame and the glass. Once installed, it will encapsulate the IGU from any and all weather conditions. Engineer designed and approved,  this specialty caulking bead is a perfect solution.

 

What is required to do it?

In this industry, like many others, it’s all about the preparation. To properly prepare the surfaces, all dirt, old material, deteriorated paint, and butyl tape will have to be scraped off with a blade. Afterwards, a proper two-stage wipe cleaning technique to ensure the adhesion of the caulking for years to come. Now, the caulking. You will require a medium modulus, UV resistant caulking that is intended for structural and non-structural glazing. This caulking is ideal for high movement locations, perfect for glass units. 

Is this bead just for glass?

An easy answer, absolutely not! This caulking bead also seals window wall systems and any location where a traditional 45 degree bead or control joint cannot be installed. Typically, we find this on metal panels, where two pieces of flat metal meet. There are many times where the leak isn’t actually around the glass seal, but in the metal panels adjacent to the glass and finding its way in. Another great reason why installing this cap bead can save you from costly replacements.

Can anyone do this bead?

From our experience, many contractors try. Not just anyone can do this. The issue we commonly find is the craftsmanship of this bead typically being lackluster. The cap bead adheres to the glass, and if it is not installed in a consistent, smooth bead, when looking from the inside, you will see the uneven caulking bead. This will ruin the owner’s view from the inside. It takes experienced, specially trained installers to install this bead. Away from the aesthetics, most installers will make this bead too small. We find that other contractors will install this too small, typically found around ¼” in size. This size will not properly adhere to the metal or glass and will certainly fail and leave you back to where you started. 

The best thing to do is keep it simple. Although the cap bead requires a highly experienced installer, the simplicity of this bead will protect your property from leaks and drafts without a more invasive and costly project. So the next time you come across leaks, or are looking to extend the life of your window systems, the cap bead is there for you. ArmourCo is here to do it.

Scroll to Top