Could I undercut door casings myself in an Ottawa home?

Undercutting door casings is one of the few flooring prep tasks that a handy homeowner can reasonably do themselves — it's straightforward, low-risk, and doesn't require a contractor's license.

What Undercutting Involves

The goal is to cut the bottom of door casings (and door jambs) so your new flooring slides cleanly underneath, creating a professional finished look without the need for awkward trim pieces. You're essentially creating a gap equal to the thickness of your new flooring plus any underlayment.

The Right Tool for the Job

The most common approach is using an undercut saw (also called a jamb saw or flush-cut saw). You simply lay a scrap piece of your new flooring flat on the existing subfloor as a guide, rest the saw on top of it, and cut horizontally through the casing. An oscillating multi-tool with a flush-cut blade works well too, especially in tighter spots. A standard handsaw can work in a pinch, but it's harder to keep the cut level and consistent.

A Few Things to Watch For

Always cut slightly higher than your flooring sample to account for the underlayment or membrane beneath it — a thin cardboard spacer on top of your flooring sample works well as a guide. Be careful around door jamb anchors or any fasteners hidden in the casing. In older Ottawa homes, casings may have multiple layers of paint or be made of older hardwood, so a sharp blade matters. If your home has heritage trim or ornate Victorian casings, you may want a professional to handle it to avoid damaging irreplaceable millwork.

Ottawa-Specific Context

This task doesn't require any permits or licensed trades — it's purely cosmetic prep work. That said, if you're having Ottawa Floor Install handle your flooring installation, this step is typically included as part of the installation process, so there's no need to do it separately.

Practical Tip

Do a dry run with a scrap piece before committing. Cut one casing, slide your flooring sample under it, and check the fit. The flooring should slide underneath with light resistance — not too tight, not with a visible gap above it.

If you'd like a professional to handle the full installation including all prep work, Ottawa Floor Install offers free consultations and estimates for Ottawa-area homeowners.