Sound Deadening Car Doors

Doors are the first job worth doing on most cars. The outer skin is a large, thin, unsupported panel sitting about thirty centimetres from your ear, and it is the easiest panel on the whole vehicle to reach. Shut a door on an untreated car and you hear it. Shut one after a pair of sheets has gone on and you hear the difference straight away.

This page covers where the sheets go, how many you need and the two things you must not cover.

Is sound deadening car doors worth it

Yes, and it is the job with the best result for the effort. You are not chasing silence. You are stopping a thin panel from ringing, which changes the character of the noise more than the volume of it. Road roar arrives less harshly, the door shuts with a solid sound instead of a hollow one, and door speakers stop fighting a panel that is vibrating behind them.

If you only ever treat one part of the car, treat the doors. For what sound deadening does and why mass is what stops a panel ringing, read our guide to car sound deadener explained.

What you need for a pair of doors

Each sheet is 50 x 32cm, runs around 2mm thick at 3kg per square metre, and carries an aluminium top layer. Four sheets is 0.64 square metres. Doing all four doors is the twelve-sheet pack, which includes the roller.

Taking the door card off

Work slowly. Door cards are held by screws behind small covers, screws inside the pull handle and grab handle, and clips around the edge.

1. Wind the window fully up and disconnect the battery if the door has powered mirrors or windows.
2. Find and remove every screw. Check inside the door pull, behind the armrest and under any plastic cap.
3. Release the clips around the perimeter with a trim tool, working from the bottom corner upward.
4. Lift the card up and off the window sill rather than pulling it straight out.
5. Unplug the loom connectors and the door handle cable before you carry the card away.

Behind the card there is usually a plastic or foil moisture barrier glued to the door frame. Peel it back carefully and keep it. It goes back on when you are finished.

Where the sheets go on a door

The outer door skin, through the access holes

This is the panel that matters and it is the one you can reach through the large cut-outs in the inner frame. Cut a sheet to fit, feed it through the hole, and press it against the inside face of the outer skin. Aim for the middle of the panel. You do not need edge-to-edge coverage, because the edges are already braced where the skin folds over.

Two sheets per front door is a sensible target. One large piece works better than four small ones.

The inner door frame, around the speaker

The flat sections of the inner frame ring too, and a sheet around the speaker aperture gives the speaker a firmer surface to push against. Cover what is flat and reachable. Leave the pressed ribs alone, they are already stiff.

The door card itself

If the plastic card flexes when you press it, a small piece on its back face stops it buzzing. This is optional and it is the last thing to do, not the first.

The two things not to cover on a door

Drain holes. The bottom edge of every door has holes that let water out. Water gets past the window seal on every car, by design. Cover those holes and the door fills up and rusts from the inside. Check the bottom edge before and after and make sure every hole is clear.

Anything that moves. The window regulator, the runner channels, the latch mechanism and the linkages all need clearance. If a sheet is near a moving part, trim it back. Wind the window all the way down and all the way up before the card goes back on.

Fitting the sheets to a door

Clean the metal with a degreaser and let it dry. Adhesive does not stick to oil, wax or dust and a sheet that lifts is worse than no sheet.

Cut the piece to shape first and test fit it dry. Peel the backing, place one edge, then press down from the centre outward so you do not trap air. Run the roller over the whole face and then along every edge, hard. The roller is not optional. A sheet that is only pressed on by hand will lift at a corner within a year.

Put the moisture barrier back. Refit the card, reconnect the loom, and check the window and the lock work before you do the next door.

How much for all four doors

Rear doors are usually smaller than fronts and take one sheet each. Buy the twelve-sheet pack if you intend to do the whole car eventually, because you will use it.

Car door sound deadening questions

How many sheets per car door?

Two for a front door and one for a rear door on most cars. The four-sheet pack does a front pair and the twelve-sheet pack does all four.

Does sound deadening a car door stop road noise?

It reduces the drumming and hollowness that the door panel adds. Road noise also comes through the floor, the wheel arches and the boot, so doors are a first step rather than a complete answer. The car sound deadening mats page shows what a full job covers.

Can I put door sound deadening over the factory plastic sheet?

No. The sheets go on bare, clean metal. Peel the plastic barrier back, do the work, then put the barrier back over the top.

Do I need to cover the whole door skin?

No. Mass in the middle of the panel does the work. The folded edges are already stiff, and covering them uses material for very little gain.

What about heat in the doors as well as noise?

A deadening sheet adds mass, not insulation. If you want both, read our guide to heat and sound insulation for vehicles.

Get the right pack for your doors

Tell us your vehicle and which panels you plan to do. Call 1300 44 33 34 or email sales@koolwrap.com.au and we will tell you what to order. Kool Wrap has supplied heat and sound protection in Australia since 1995, and we ship Australia-wide with tracking sent after dispatch.