Installing Replacement Windows in Brick or Stone

Why do Window Replacement Contractors Install the way they Do?

What I am about to share with you is probably the most controversial topic in home renovation today. I am going to address the topic of replacement window installation in masonry veneer homes.

If you google it, your search will result in a myriad of different techniques to ensure that you install replacement windows with a focus upon blocking moisture, the elements, and prevent insects from entering your home and destroying your wood framing. The techniques you will see and hear about are very expensive Band-Aids, meant to save the installer and the company time and money on what has become one of the quickest and most profitable projects in the business.

I have been a window installer and am now a dealer for high-end replacement windows. That experience alone is not adequate to advise you on the best way to install replacement windows in your home. With the added weight of more than 40 years in all phases of new construction and home renovation, I can confidently say that if you purchased replacement windows for your brick, stone, or stucco home, they were installed improperly, and will not last the warranty.

If your windows were not installed from the inside of your home, behind the masonry veneer, they were not installed properly. Your windows will not stand up to the elements, nor will they provide the performance you paid dearly for. With the average replacement window installation running between $2500 and $3500 per window, you don’t want to face costly repairs in as few as five years.

Why did the contractor install your windows inside the masonry perimeter rather than the way I recommend?

The simple answer is Trouble, Time, and Money.

Very few window replacement companies, nor their installers, have any competency in other phases of construction. They are in the window business precisely because it is quick and easy, and very profitable. Their sales pitch includes talk of lifetime warranties, energy savings, and sustainability. Their window specifications tout R and UV values, resistance to heat and air transference, and rigidity against wind and stress to the window frames.

Let me ask you a reasonable question: If you installed that window in a tent, how much good would it do? Would the window perform to a level that you would feel your money paid was well invested? It would perform as advertised but the installation would not. How long would that window last in that environment before you had to repair the installation?

That is a ridiculous comparison, you say. Is it? If your windows have been inserted into the perimeter of your masonry opening, the window is smaller than that opening, or it wouldn’t fit in the opening. When the window is inserted, how does the installer plug the spaces around the window? He uses some type of caulk. That means that your lifetime window will perform only as long as the caulk joint lasts, usually about five years.

But wait, you say, my installers built wooden frames inside the brick and fastened the windows to that. They used window tape, and they caulked over that. That means that in five years or so you will have a pervious point where the new wood will be exposed to the elements. That buys you more time before you feel air flow, or detect water penetration, but it is still not a lifetime installation for your lifetime warranteed windows.

If you are an installer, or a homeowner who wants to deny that the installer messed up your expensive install, consider this. When a window is installed in a new home, the window is attached to the frame using nail fins, window tape, sill tape, and a sealant. The brick is installed against the window. Mortar is used to seal the joint where the window meets the masonry. A bead of a petroleum-based sealant is laid over the mortar to finish the seal. The frame of the window is larger than the brick opening, effectively sealing the window with the strength and weight of the window frame.

Why are replacement windows installed differently than the original windows?

They shouldn’t have been.

When I install replacement windows in a masonry clad home, I remove the sheetrock and the windowsill and install the windows from the inside. The window fits snugly in the wooden framing, and tightly against the inside of the masonry veneer. I insulate around the window from the inside, then use a high-performance silicone sealant. I install new sheetrock, and a new sill, tape, float, and texture the sheetrock, then paint it all. I use the same silicone sealant at the tight joint where the masonry and the window frame touch.

In the typical window installation, where the window slides into the masonry opening, the caulk or sealant is subject to structural movement over time. The sealant was not designed to create a broad barrier between two separate surfaces. A sealant product is designed to crate a coating over a tightly bonded joint. It is an overlay, not a stretchy wall. Even an 1/8-inch separation will dramatically reduce the performance and life of the most highly rated sealant.

Installing a wooden frame inside the opening is better than relying upon the flexible sealant, but it is far from a maintenance free solution. Most windows are purchased with maintenance free operation in mind. Exposed painted wood, and a wide caulk joint, is not acceptable when installing your expensive windows. That is not what you purchased, and that is not what you want.

You may believe that window installers feel that the added expense of removing interior window materials, then replacing them, is not cost effective, but that is not the case. The process they perform with window blocking, impervious sealants, and seal tape, is as expensive and just as labor intensive. They don’t do it the way I recommend because they lack the expertise to do it that way.

Doesn’t it make sense to you that somewhere in the $2500 to $3500 you paid per window, your window contractor could fit a couple sheets of sheetrock, a few board feet of sill material, and a painter into the job costs? Of course they can – And they should!

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