Kingspan Insulation
Kingspan Group


Residing header

If you’re residing your home, your contractor will handle the job in one of two ways—by tearing off the old siding first or by installing new siding directly over the old siding. Either approach is perfectly legitimate, depending on the situation with your walls and your objective in residing your home.

Siding Installed Following Tear-off of Old Siding
If your wall sheathing is in good condition, this installation is much like new construction. It is an opportunity to create a wall system that is more resistant to water and air infiltration. GreenGuard products for this application include building wraps, seam tape, and window flashing (if windows are replaced.) For installations of vinyl, wood, or fiber cement siding, RainDrop® building wrap can be used to create a drainage space behind the siding. For maximum protection, DC14 is an XPS drainage mat with drainage and drying capabilities on both sides.

XPS Underlayment Over Existing Siding
Contractors typically apply GreenGuard XPS underlayment over existing siding when vinyl siding is being used. Covering the old siding with a single layer of XPS underlayment does several useful things:

  • Provides a level surface on which to install new siding for a smooth, even wall
  • Helps block water that gets behind the new siding
  • Helps reduce or eliminate drafts, if the seams are taped
  • Adds insulation to the exterior of your wall

GreenGuard siding underlayments are the very best. They are stiffer, more resistant to water absorption, and less prone to crumbling than common “bead-board” type underlayments.

Reflective Insulation
Some GreenGuard underlayments come with a reflective facer. Reflective surfaces enhance insulating materials by reflecting radiant heat. Performance of reflective surface products can be confusing and subject to some exaggerated claims. For additional information, please see the Frequently Asked Questions section on this site or visit