Installing Hybrid Flooring Around Door Frames

📖 12 min read

Door frames are where DIY flooring installations either look professional or look amateur. Get this detail right, and your hybrid flooring flows seamlessly from room to room. Get it wrong, and you end up with ugly gaps, messy silicone fills, or planks that don't sit flat.

The good news? There's a proper technique that professionals use, and it's not difficult once you know how. The key is undercutting – cutting into the bottom of the door frame so your flooring slides underneath, rather than trying to cut the flooring to fit around it.

This guide covers everything: when to undercut, how to do it, what tools you need, and how to handle tricky situations like architraves, door stops, and transitions between rooms.

🔴 IMAGE 1 (Hero): Close-up of hybrid flooring sliding neatly under an undercut door frame – shows the clean, professional finish. The gap between flooring and frame should be invisible. Ideal size: 1200x600px landscape.

Why Undercutting Door Frames Matters

There are really only two ways to handle flooring at a door frame:

Undercutting takes an extra 10-15 minutes per door frame. That small time investment makes the difference between a floor that looks installed by a professional and one that looks like a weekend hack job.

Tools You'll Need

You don't need expensive specialist tools. Here's what works:

My Tool Recommendation

If you're doing more than 2-3 door frames, invest in (or hire) an oscillating multi-tool. Brands like Ozito, Ryobi, or Makita all make affordable options. The flush-cut blade makes undercutting quick and precise. You'll also use it for dozens of other jobs around the house.

For a single door or tight budget, a Japanese pull saw (about $25 from Bunnings) and a sharp chisel work fine – just takes more time and care.

How to Undercut Door Frames: Step-by-Step

Here's the professional method:

Step 1: Set Your Cutting Height

You need to cut just high enough for your flooring (plus underlay if not pre-attached) to slide under. Too high leaves a visible gap; too low and the flooring won't fit.

1. Take an offcut of your hybrid flooring
2. If using separate underlay, place that on the subfloor first
3. Place the flooring sample on top, flat against the door frame
4. This is your cutting height – mark it on the frame with pencil
5. Add 1-2mm clearance to allow the flooring to slide freely

Most hybrid flooring is 6-10mm thick. With pre-attached underlay, you're typically cutting 7-12mm from the bottom of the frame.

Step 2: Protect Your Work Area

• Lay drop sheets to catch sawdust (there will be a lot)
• If existing flooring is staying, protect it from scratches
• Have a vacuum ready for cleanup

Step 3: Make the Cut

With an oscillating multi-tool:

1. Rest the flat side of the blade on your flooring sample (as a depth guide)
2. Turn on the tool and let it reach full speed
3. Push the blade horizontally into the door frame, keeping it flat on the sample
4. Work across the width of the frame in smooth passes
5. Cut both the architrave AND the door jamb behind it

With a hand saw and chisel:

1. Use your flooring sample as a guide for the saw
2. Make a horizontal cut across the frame, keeping the saw flat on the sample
3. Cut as deep as you can with the saw
4. Use the chisel to remove the cut section and clean up
5. Check depth with your flooring sample

🔴 IMAGE 2 (Cutting process): Person using oscillating multi-tool to undercut a door frame, with flooring sample visible as depth guide. Shows the technique in action – could include safety glasses and dust. Ideal size: 1000x600px landscape.

Step 4: Clean Out the Cut

• Remove all cut material and sawdust
• Use a chisel to clean up any remaining bits
• Vacuum thoroughly
• Test fit your flooring sample – it should slide under smoothly

Step 5: Repeat for All Door Frames

Do all your undercutting before you start laying flooring. It's faster and keeps sawdust away from your installation area.

Handling Architraves

Architraves are the decorative trim pieces around your door frame. They sit in front of the jamb and need undercutting too.

Standard Timber Architraves

Most Australian homes have painted timber (or MDF) architraves. These undercut easily:

• Cut both the architrave AND the jamb behind in one pass where possible
• The architrave is usually thinner than the jamb – it cuts quickly
• MDF architraves can be dusty – wear a mask

Thick or Ornate Architraves

Older homes sometimes have thick, ornate architraves that are harder to undercut:

• You may need multiple passes with the oscillating tool
• Consider removing the architrave entirely, laying flooring, then reinstalling
• If the architrave is valuable (heritage), be extra careful or consult a professional

No Architraves (Shadowline/Square-Set)

Modern homes often have "shadowline" or "square-set" corners with no architraves – just a small reveal where the plasterboard meets the frame.

In this case:

• You only need to undercut the door jamb itself
• The expansion gap will be visible at the edge – you'll need scotia or quarter-round moulding to cover it
• Or use colour-matched silicone (less ideal but works)

Door Stops and Jambs

A door frame has several components. Here's what you're dealing with:

The Door Stop Question

The door stop is the thin wooden strip that the door closes against. Usually, you don't need to undercut it because:

• Your flooring stops at the door jamb, not behind the door stop
• The door stop typically sits on top of the flooring or at the transition point

However, if your flooring runs continuously through a doorway (no transition strip), you may need to remove the door stop, lay flooring, then reinstall the stop on top. This is common for internal doorways where you want seamless flooring flow.

Sliding Flooring Under the Frame

Once your frames are undercut, here's how to install the flooring:

For Planks Running Perpendicular to the Door

This is the easy scenario:

1. Lay planks as normal up to the door frame
2. The last plank slides under the frame, hiding the expansion gap
3. Ensure you maintain your expansion gap at the back (hidden under the frame)

For Planks Running Parallel to the Door

This requires a bit more work:

1. You'll need to cut the plank lengthwise to fit under the frame
2. The tongue or groove may need trimming to allow the plank to drop in
3. Approach from inside the undercut and angle the plank into position
4. You may need to glue this plank (PVA on the click-lock) since normal clicking isn't possible

Door Transitions Between Rooms

Doorways are natural transition points. Here's when to use different approaches:

Option 1: Continuous Flooring (No Transition Strip)

Best for: Internal doors between rooms with the same flooring

• Flooring runs straight through the doorway
• Undercut both sides of the frame
• Looks seamless and high-end
• Requires careful planning of plank layout

For open-plan living, continuous flooring through doorways creates a sense of space and flow.

Option 2: T-Moulding Transition

Best for: Where two floating floors meet, or at expansion breaks

• T-shaped strip sits in the doorway
• Allows independent expansion of each floor area
• Good for very large areas that need an expansion break
• Available in matching colours

Option 3: Reducer Strip

Best for: Where hybrid flooring meets a lower floor (tiles, vinyl, concrete)

• Ramps down from higher floor to lower floor
• Creates smooth transition without a trip hazard
• Often used at bathroom or laundry doorways

Option 4: End Cap / Square Nose

Best for: Where flooring ends at an external door or step

• Provides a clean finished edge
• Covers the expansion gap at the floor's edge

We stock a full range of transition strips, reducers, and accessories to match our flooring colours.

🔴 IMAGE 3 (Transition options): Visual showing different transition strip types – T-moulding, reducer strip, and end cap – with labels explaining when each is used. Could be product photos arranged together or a simple diagram. Ideal size: 1000x600px landscape.

Common Mistakes to Avoid

When You Can't Undercut

Sometimes undercutting isn't possible. Here are your alternatives:

Metal or Aluminium Frames

Some modern homes have metal door frames that can't be easily cut:

• Option A: Use a metal-cutting blade on your oscillating tool (slow and noisy, but works)
• Option B: Install a transition strip at the doorway instead
• Option C: Cut flooring to fit and use colour-matched silicone to fill the gap

Sliding Door Tracks

Sliding doors often have tracks that can't be undercut:

• Use a reducer or end cap at the track
• Ensure flooring doesn't interfere with door operation
• Check clearance before installing

Heritage or Valuable Frames

If door frames are heritage-listed or valuable:

• Consider using scotia or quarter-round moulding instead of undercutting
• Consult a professional for advice
• The NSW Heritage Council and similar state bodies provide guidance on working with heritage properties

Rental Properties

If you're installing in a rental and can't modify frames:

• Use scotia moulding to cover expansion gaps
• Transition strips at doorways
• Colour-matched silicone (removable when you leave)

Special Situations

Bi-Fold Doors

Bi-fold doors (internal or external) have tracks that need consideration:

• Top-hung bi-folds: May be able to undercut the frame normally
• Bottom-track bi-folds: Use a transition strip at the track – don't undercut
• Check door clearance after flooring is installed

Cavity Sliders (Pocket Doors)

Cavity sliding doors disappear into the wall:

• The frame can usually be undercut normally
• Be careful of the cavity mechanism inside the wall
• Don't cut too deep on the cavity side

Double Doors

French doors or double-entry doors:

• Undercut both sides of the frame
• For external double doors, consider waterproofing at the threshold
• Transition strip may be better than undercutting for external doors

Door Trimming: Will Your Doors Still Close?

Adding flooring raises your floor height. Check if your doors need trimming:

1. Measure your new flooring thickness (including underlay)
2. Check current gap under each door
3. If flooring thickness exceeds the gap, you'll need to trim doors

Most interior doors can be trimmed by 10-20mm from the bottom without issues. Beyond that, you may affect the door's structure (hollow-core doors have limited solid material at the bottom).

The Housing Industry Association (HIA) recommends a minimum 10mm gap between door bottom and floor covering for proper operation and air circulation.

Ready to Tackle Those Door Frames?

Undercutting door frames is one of those skills that separates a professional-looking DIY install from an amateur one. It takes a bit of extra time and the right tools, but the result is worth it – seamless flooring that flows through your home without visible gaps or messy filler.

If you have questions about your specific door frame situation, or need advice on tools and techniques, give us a call on 0431 311 633 or send us a message. We're happy to help you get a professional result.

Last updated: December 2025 · Written by the team at Hybrid Floors Australia