Window Frame Materials Can Change Your Installation Approach

Jim Snyder
June 27, 2014
COLUMN : From the Field | Operations

For consumers, choosing a frame material is crucial to the window selection process. There are, after all, a lot of options available. It’s the job of the salesperson to find the best fit for the client and application.

Consumers typically choose a frame material based on the benefits it offers. But there is another factor to consider, and that is how the frame material can ease, or complicate, the installation process. This affects the installer, the labor cost, and possibly, the final result.
I’m not suggesting that ease of installation be the dominant factor when helping clients select window frame material, nor am I promoting any particular frame material. I’m merely stating that frame material can change the installation approach, possibly increasing installation time or changing the practicality of an installation, especially in some replacement applications. There is a certain amount of installer adaptation for fitting different frame materials—even in the same type of installation—to the opening.

Material Affects Profile, Profile Affects Fit

Each frame material has special properties. Wood is milled; vinyl and aluminum are extruded; and fiberglass is pultruded. As a result, each material has a different profile and structure, even more so with combination frames like clad-wood. Quite often, a proposed replacement product has a different frame material than the existing product. For a full-frame replacement, this can be a major consideration for the installer.
When an old product is removed, it leaves a cavity for the replacement product to fill. It’s easier to fill the void by replacing an entire wood frame with another wood frame than with a non-wood frame. The reverse is true as well. Frame offsets, sill heights and factory jamb depths are inconsistent between frame types. Imagine a child trying to fit his foot in the paw print left in the sand by a large dog. It doesn’t fit the mold.

Material Affects Workability

Different frame materials require different tools and skill sets. Working with vinyl is quite different than working with fiberglass, aluminum or wood. They all vary in rigidity, weight and scratch resistance. Some require predrilling. Cutting techniques are different. Fasteners are different. Perhaps wrapping exteriors with coil stock is a regular part of an installer’s practice, thus requiring a brake. While these factors all might seem minor, it’s surprising how differently equipped an installer must be moving from one material to another.

Each Frame Material 'Adapts to Fit' Differently in the Field

Even though most products are available in custom sizes, sizing challenges still exist. Mull spreads, sill nose heights and factory exterior casing
widths can really make a difference in fit. For wood products, variations are usually available from the manufacturer. If not, installers can still modify them in the field by shaving casing or even adding to the sill nose. Nonwood products are more limited in this regard, but make up for it with frame expanders and a variety of accessories.

Jamb Depth and Attachment Options

Jamb depth can make an installation easier…or harder. Wood and woodclad products typically reach the entire jamb depth, and interior casing is required. The majority of other products require site-built interior returns of some sort, and interior casing might be optional. Some replacement scenarios require reusing and/or cutting back existing returns.
Attachment options also play a role in the installation. Thru-casing fastening, thru-jamb fastening, installation brackets and nail fins all vary between frame materials. This factors in when considering access for anchoring the window.
Having said all of this, there are certain situations where material type is nearly a moot point for the installation process. For example, an “insert” in an existing wood frame is fairly straightforward, regardless of the insert frame material.
Promote the best product for the application, but keep the installation process in mind.
Jim Snyder is an AAMA-certified FenestrationMaster and InstallationMaster who shares his years of installation field experience as an industry writer, speaker, trainer and project/product consultant for dealers and manufacturers. A member of various industry organizations, Snyder also is involved in instructional document creation and revision. Contact him at