Fenestration Replacement Presents Its Own Set of Challenges

Jim Snyder
March 25, 2014
COLUMN : From the Field | Strategies & Practices
During a replacement installation, the installer is likely the only trade on the job, and he or she controls the quality of the finished project. But the existing condition of the structure, fenestration or components can limit installers’ ability to do their job properly if conditions won’t accommodate good installation practices. To make matters worse, industry instructions for many replacement situations don’t exist.
 
Typically, replacement comes in two forms: 
  • Using a replacement product in an existing frame, or 
  • Doing a full-frame replacement, which is more challenging, especially for membrane drainage wall systems.
Replacement products (inserts, sash kits, flush fin) greatly reduce complications when they can rely on existing frames. There is no disruption to the wall interface, and the rough opening or pocket is easy to measure. Instructions are well written and readily available. 
 
Full-frame replacement, on the other hand, is more like an organ transplant. It’s much more invasive and you have to anticipate what’s inside before making the incision. After removing the window, you are forced to work with the surrounding rough opening and weather membrane. There can be complications along the way such as wood rot. You might find termites that you’re forced to deal with because you can’t just put the old window back in. Post-installation, you don’t want any water intrusion because that can be fatal to the project.
 
Thankfully, no one’s life is at stake in our case. 
 
Full-frame replacement is highly dependent on exterior veneer, existing membrane and type of original installation. The combinations are nearly endless, making standardized instructions difficult to find, or even write for that matter.
 

The How-To

For a long time, full-frame replacement relied on new construction installation instructions. These are well written and readily available through manufacturers and industry “Standard Practice for Installation” documents, but the sequence for replacement is not the same as it is for new installation. Essentially, you have to shoehorn the new product into the opening while accommodating out-of-square perimeters of the exterior facade and hopefully fitting to existing interior trim and/or returns. The biggest challenge is anchoring the new unit and tying back into the wall interface without removing the fa├žade. Is it even doable? 
 
Seeing the need for full-frame replacement instructions, some manufacturers have created them in recent years. Industry groups are joining forces to address this as well. Not only do these replacement instructions tackle the installation but also the removal of the existing product. That by itself requires discretion and skill. An installer has to be careful not to disrupt anything outside of the installation perimeter. 
 
These instructions don’t capture every scenario, and probably never will, but I’ve been impressed with the flexibility and adaptations of these replacement instructions up to this point. For issues not addressed, sometimes the skill and discretion of an experienced installer is the best medicine. 
 

In next month’s column, I’ll offer some solutions. 

Backed by two decades of extensive hands-on experience, Jim Snyder is a technical writer, trainer and project/product consultant for the fenestration industry. Always seeking best practices, he has journaled and cataloged many years of fenestration-related activities and is an active member of AAMA, FMA and WDDA. His weekly blog at windowjim.com ties field-related topics to the rest of the industry. Write him at jim@windowjim.com.