Fitting a Matwell in a Timber Floor: Step-by-Step Guide

To fit a matwell in a timber floor, you first decide whether the floor is fixed or floating. Then you cut or build a recess to the depth of your mat, check it is square, dry-fit a rigid frame with tight mitred corners, and fix it so the mat finishes flush with the boards. Get the depth and the squareness right and the rest is straightforward. This guide takes you through each stage, from the checks before you cut to cleaning once the frame is in use.

TL;DR

• A matwell is a recess that lets an entrance mat sit level with the surrounding floor, framed so the edges stay crisp and safe underfoot.
• Work out first whether your timber floor is fixed or floating. That decides how the frame is fixed and how much room it needs to move.
• Measure the mat depth, then the recess depth, then both diagonals, and dry-fit before you fix anything.
• Leave a small clearance around the mat, mitre the corners tightly and check the finished frame is flush so nobody trips.
• Vacuum the well regularly. Grit trapped under a mat wears both the mat and the floor.

Table of Contents

• What a matwell is and why timber floors need care
• Before you start: the checks that save a re-do
• Measuring the well
• How to install a matwell frame in a timber floor
• Fitting the corner joints properly
• Choosing the right frame for your project
• Perspective from our workshop
• Keeping the matwell clean
• Our matwell frames
• FAQ
• Sources

What a matwell is and why timber floors need care

A matwell is a shallow recess at an entrance that holds a mat so its surface sits level with the floor around it. The frame around the edge protects the floor finish and gives the mat a clean border. The Contract Flooring Association’s guide describes a matwell frame as being recessed into the subfloor to take an entrance flooring system, positioned so that it gives a smooth transition to the adjoining interior floor finishes (CFA Guide to Contract Flooring, 8th edition).

Timber adds a few wrinkles that tile or screed do not. Boards expand and contract with the seasons. Engineered and laminate floors are often floated, so they are not glued or nailed down. Solid boards sit on joists, which limits how deep you can cut. Each of these affects how you build the well and what you fix the frame to.

If you cannot cut a recess at all, you can still get a tidy result. Our own matwell frame can be fitted on top of existing flooring, with the mat sitting inside it. You lose some depth, so it suits thinner mats, but it avoids cutting into the structure.

Before you start: the checks that save a re-do

Most matwell problems start before the first cut. Spend ten minutes on these.

Fixed or floating floor?

Lift a threshold or look at the edge of the room. If boards are glued, nailed or screwed to joists or a sub-base, the floor is fixed. If the floor clicks together and rests on an underlay, it is floating. A floating floor needs an expansion gap at its edges, and it must be free to move. A frame fixed rigidly across that movement can cause lifting or gapping later. Follow the flooring manufacturer’s instruction for the gap, and keep the frame from pinning the floor down where it needs to move.

Our solid brass matwell frame is supplied with pre-attached self-adhesive tape that is heat and moisture resistant and suitable for underfloor heating. We design it to be stuck directly to non-floating floors that have no expansion or movement. You can see the range on our matwell flooring trim page.

What is under the boards?

Before cutting, find out where joists, pipes and cables run. A pipe and cable detector is cheap insurance. Joists tell you how far you can cut: notching a joist is a structural matter, so if the well needs to go deeper than the boarding, speak to a builder or structural engineer rather than guessing. Often the better answer is a shallower mat.

Choose the mat first

Buy or measure the mat before you build the well. Its thickness, including any backing, sets the depth. Frames come in set heights, so match them to the mat and the floor build-up, not the other way round. Our guides on matwell frame depth and matching depth without binding cover this in more detail.

Clear the work area

The CFA guide advises clearing rubbish from each work area and removing surface contamination, preferably by industrial vacuuming, so the surface is ready to receive the next product (CFA Guide to Contract Flooring). In a timber floor that means dust and offcuts out of the recess, and no loose splinters or old adhesive under the frame.

It is also worth laying dust sheets and, once the job is done, thinking about the rest of the boards. If you are moving heavy furniture back across the hall, there are simple ways to protect hardwood floors from the marks that heavy legs leave.

Measuring the well

Accurate measuring is what separates a frame that drops in from one that needs three attempts. Our advice, which matches how most fitters work:

1. Decide the mat size you want, then add the clearance around it. We suggest 3 to 4 mm all round so the mat does not bind and can be lifted out for cleaning.
2. Measure the recess length and width at several points, not just one.
3. Measure both diagonals. If they differ, the recess is out of square and the frame will need adjusting rather than four identical cuts.
4. Measure the recess depth at each corner.
5. Write everything down before you order or cut.

Our matwell frame sizes guide goes through measuring and ordering so you only order once.

How to install a matwell frame in a timber floor

The steps below suit a fixed timber floor with a cut recess. For floating floors, adapt the fixing as described afterwards.

Step 1: Mark out and cut the recess

Mark the outline with a pencil and straight edge, using the measurements above. Set a circular saw or plunge saw to the depth of the boarding and cut inside the line, finishing the corners with a chisel or multi-tool. Lift the boards inside the line. Take care not to cut into joists or services, and keep the cut edges square and clean, because the frame will sit directly against them.

Step 2: Prepare the base

The well needs a flat, firm base at the right depth. Where the boarding has been lifted you may need a sheet of ply or a batten fixed between joists to carry the mat. Make sure it is level. Vacuum thoroughly. The CFA guide notes that keeping the base clean helps adhesives bond, which is why the vacuuming matters before any frame or mat goes in.

Step 3: Dry-fit the frame

Lay each length around the recess without fixing it. Check that the frame sits snug to the edges of the boards, the corners meet, and the top of the frame is level with the floor. Place the mat inside and check the clearance. Holding the mitres closed with masking tape lets you walk across the doorway and see how it feels before anything is permanent.

Step 4: Fix the frame

On a fixed floor, you can fix the frame in one of two ways:

• Adhesive tape or adhesive. For a flat, clean, non-floating surface, our matwell frame comes with pre-attached self-adhesive tape. Press it down firmly along its length once you are happy with the position.
• Screws. Where the frame has fixing holes, countersink the screws so the heads sit below the surface, and fix into solid material, not just thin boarding.

On a floating floor, do not trap the floor. Fix the frame to the sub-floor in the well and leave the floating boards free to move under the frame’s lip, or use a frame designed for floating floors, following the flooring maker’s instructions on the gap.

Step 5: Lay the mat and check flush

Drop the mat in. Run your hand across the joint between the frame, the mat and the boards. Nothing should catch. A mat that sits proud by even a few millimetres is a trip point, and one that sits low leaves a lip. If it is out, adjust the packing under the mat rather than the frame.

For more on how edge trims behave generally on different floors, our step-by-step guide to installing flooring edge trims covers the basics of cutting, positioning and fixing.

Fitting the corner joints properly

The corners are where a matwell looks either professional or rushed. There are two routes.

Site-cut mitres. You cut each end at 45 degrees with a mitre block or saw and a fine-toothed blade made for metal. Clamp the profile before cutting, because metal moves under blade pressure. Deburr the edge with a needle file and true the angle. Work from a datum line so any small error ends up at the least visible corner, not the one facing the door.

Pre-formed corners. For high-visibility entrances, a pre-made corner removes the risk of an off-angle cut. Many fitters choose this for commercial doorways.

Whichever you choose:

1. Dry-fit all four corners first.
2. Check the corners are tight and the faces line up, so there is no step between the two lengths.
3. Fix each length so it cannot creep, then check again.
4. If the recess is out of square, trim or pack one side instead of forcing the cut.

We set out the full approach, including the clearance we recommend, in our guide to matwell corner joints. A solid brass profile holds a mitre line cleanly, which is one reason we make our frames from it.

Choosing the right frame for your project

The frame has to suit the floor, the depth and the traffic. Questions to ask:

Door clearance catches people out. A mat that is slightly too thick can make a door drag. Our guides on retrofit matwell frames, loose matwell frames and commercial entrance matwells cover door binding and depth for different situations. If you are weighing finishes, see our matwell edging options.

A matwell is one of the hardest-working spots in the house. Every visitor wipes their feet there, and every trolley, buggy and heavy boot crosses the edge. Cheaper frames made of soft or hollow materials tend to split, bend or dent in this spot. A solid brass frame is made for that knocking.

Perspective from our workshop

Most of the matwell calls we take are not about the mat. They are about the edge. The mat is the easy part, and the frame decides whether the entrance looks finished or tired after a year.

We make our trims from solid brass and finish them by hand in the UK, then powder coat them in one of 10 finishes. We do that because a matwell frame lives in the hardest spot in the house. It gets kicked, dragged over and stood on. A frame that is meant to last should not split, bend or dent, and brass does not.

Our advice to fitters and homeowners is always the same. Measure twice, dry-fit the lot, and decide on the floor type before you decide on the fixing. If you are not sure about depth or door clearance, ask us before you cut. It costs far less than a recut.

Matt

Keeping the matwell clean

A matwell collects grit, and grit is what wears mats and floors. The CFA guide recommends keeping the matwell free from dust, dirt and debris by vacuuming, ideally with an industrial vacuum, and keeping the base clean so the matting does not become uneven or wear prematurely (CFA Guide to Contract Flooring). In a home, that translates into a simple routine:

• Weekly: vacuum the mat surface and the edges of the frame.
• Monthly: lift the mat out, vacuum the well and run a damp cloth over the frame.
• After wet weather: let the mat dry before replacing it, so moisture does not sit against the timber.

For the frame itself, a soft damp cloth and a dry wipe are all it needs. Avoid abrasive pads and harsh chemicals on a hand-finished surface, as they can mark the finish. Because we leave a small clearance around the mat, you can lift it out easily without scraping the frame.

Our matwell frames

We supply solid brass, hand-finished matwell frames in 10 finishes, powder coated to match your hall and doorway furniture. They are made in the UK, and we offer free samples and fitting guidance so you can check the finish against your timber before you commit. To see the range and order, head to our matwell flooring trim page.

If the matwell sits beside carpet, tile or laminate, you will also want trims for the transitions around it. Our carpet to tile trims and laminate flooring threshold strips are made in the same solid brass.

FAQ

Can I fit a matwell in a floating timber floor?

Yes, but the floor must stay free to move. Follow the flooring maker’s instructions for the expansion gap, and do not rigidly fix the frame across floating boards. Fix the frame to the sub-floor in the well, or choose a frame suited to floating floors.

How deep should the matwell be?

The recess should match the thickness of your mat, including its backing, so the mat finishes level with the floor. Frame heights are set, so choose the frame and mat together. Check our depth guides if you are close to the limit of the boarding.

Do I need to cut into the floor?

No. Cutting a recess gives you more depth for a thicker mat, but you can fit a frame on top of existing flooring and place a thinner mat inside. It is a sensible route when joists or services stop you cutting.

How do I stop the corners from opening up?

Dry-fit every corner, cut clean 45 degree mitres or use pre-formed corners, and fix each length so it cannot creep. Check the recess is square by comparing the diagonals before you cut.

How do I clean a matwell frame?

Vacuum the well regularly, lift the mat out to clean beneath it, and wipe the frame with a soft damp cloth, then dry it. Keeping grit out protects the mat and the timber around it.

Sources

• CFA Guide to Contract Flooring, 8th edition (Contract Flooring Association)

Recommended

• Matwell depth for fitters: Match 10–17 mm without binding
• Keep 3–4 mm Clearance: Matwell Corner Joints for UK Fitters
• 17mm or 21–23mm: Matwell Frame Depth for UK Fitters
• Fit Loose Matwell Frames First Time: 17–23mm Depth for UK Contractors