Homeowner's Guide

Window Construction & Maintenance

Why should I buy custom replacement windows?

Installing custom windows

Because custom windows fit perfectly. Stock windows, like those used by builders or sold in lumber yards, are available only in certain sizes. Since many window openings are not the same "standard" sizes as stock windows, you'll be left with several inches of open space around the entire window. Carpenters generally fill this space with gypsum board or molding. This not only reduces your viewing area and detracts from your home's beauty, but you have extra wall space to patch, paint, and decorate. Custom windows are designed, engineered, and manufactured to fit your home's size, style, and appearance without reducing your viewing area.

Can I install custom-made windows myself?

Yes, but the better question might be, "Should I install custom-windows myself?" Professional installers have all the necessary equipment to do the job right, like bending exterior trim panels to make them more visually appealing. Measuring the size of the window is extremely important as well. If your measurements are off by as little as 1/4". a custom-made window may not fit. We strongly recommend that you let a professional do the job for you.

What's the difference between vinyl, wood, and aluminum windows?

New Generation™ uiPVC — the strongest, most advanced vinyl for windows — provides the best combination of convenience and long-lasting beauty. With New Generation uiPVC, the color is through and through. It never needs painting and won't show scratches, unlike aluminum or wood windows.

Vinyl is also a better insulator. It doesn't conduct heat or cold like aluminum — a major source of lost heating/cooling energy. And it doesn't swell or shrink like wood when temperatures change. Vinyl maintains its shape, saves you heating/cooling dollars, and stays warmer to the touch.

TIP: Avoid low-grade PVC — this material can bend and bow or discolor. Be sure it's heavy-duty New Generation uiPVC.

Today the majority of replacement windows are vinyl*. But just because a window is made of vinyl doesn't mean it's superior. The design, engineering, and manufacturing of the window will help distinguish a poor window from a superior window.

* SBI Marker Profile: Windows 1999

I've heard window corners can separate and leak air. What's the best way to put windows together?

Windows (and doors) are the #1 source of a home's energy loss, and a lot of heater or cooled air can be lost through the frame (see R-factors below).

Most wood windows are put together with staples; most vinyl windows are screwed together and then caulked.The day they leave the factory, most windows are perfect. But construction methods can make a big difference five years, even twenty-five years after your windows are installed.

Look for windows in which the frame and sash corners are joined in the sturdiest way possible. The most durable process we've found is a technology called 'pinch' fusion welding.

What is pinch fusion-welding?

Pinch fusion-welding is the latest technology in window construction. It utilizes intense heat and specialized equipment to bond the corners of all four sides of a window's sash and frame into a single unit. Pinch fusion-welding results in a stronger, more stable window. It's more energy efficient because the corners remain fused and airtight for the life of the window — an important element to look for in a window's warranty.

And unlike windows welded with older equipment, pinch fusion-welded windows have attractive, trimmed welds. Both the interior and exterior of the window's corners are clean and smooth, without the bulky "flashing" or overlap that can result with the old welding technique. And they never need caulk so their virtually maintenance-free.

My old windows used putty to hold the glass i place. Is there a better way?

The use of putty for window glazing has, for the most part, been phased out. But many window manufacturers still use two-sided tape to hold their glass units against the window sash. Great Lakes utilizes a state-of-the-art process called silicone autoglazing. This method securely and permanently bonds the insulated glass unit to the sash frame and provides increased durability, energy efficiency and maintenance freedom. Manufacturing our window sashes and insulated glass units as a one-piece unit is just one of the ways you're ensured of worry-free windows.

What are the cam locks and ventilation locks?


Cam-action locks are the thumb-turn locks traditionally used on double-hung windows. They reduce drafts by tightening the sashes together.

More importantly, cam locks can improve security. Some manufacturers use two locks on windows 32" or more in width. We recommend (and provide as standard) two pick-resistant locks on double-hung windows 25" or wider, and on sliding windows of heights of 25" or more.

Ventilation-limit locks are stops in the sash which permit windows to be opened partially while retaining security. They can be an added safety advantage in homes with small children. Be sure to look for them on windows as you shop around. Ventilation-limit locks are a standard feature on all Great Lakes double-hung windows.

Next Section — Energy Efficiency

This guide is provided as a service of Great Lakes Windows, Inc., to help consumers make informed buying decisions.