Some areas require an air flow regulator, this is why all of our standard warm air vents come with one.
Why didn't my installer make the floor registers for me?
Because it is a very involved process for a seemingly simple looking product. It would take your installer a long time and plenty of patience to:
Measure and cut each of the slots in such a fragile material.
Apply fiberglass to the back for needed strength.
Profile and polish all four edges using 6 to 8 sanding steps going from course to fine.
Apply a damper to control air flow.
Metro Marble Restoration has automated most of the steps involved that is how we are able to sell our air vents at such a reasonable price.
Can a flush mount floor register be installed into an existing floor?
Yes, but it would be advisable to hire a professional tile installer.