More Installation FAILS – Folding Door “Floating” Sills

Just because a window dealer sells and installs doors doesn’t mean they’re doing it right.

One builder told me:

“Oh, we’ll just fill that in with mortar after...” 🤦‍♂️

Here’s why that’s a guaranteed failure:

• Yes, folding doors are top-supported—
  But without proper sill support, there’s no way to waterproof the base.
  It will leak. Not if, but when.

• That “floating” sill isn’t structurally anchored by any engineering standard.

• And when cement contacts aluminum, especially in saltwater environments, it’s a corrosion time bomb.

This is why I help clients write install requirements directly into contracts, vet dealer proposals, and hold teams accountable to best practices—before the install goes wrong.

Folding Door “Floating” Sills