Mavericks Bitumen Sheets — DIY Car Soundproofing

Mavericks Bitumen Sheets - DIY Car Soundproofing

DIY Latio Roof Soundproofing

Materials Required: 1/4 roll (2.5m x 1m) aluminium-backed bitumen sheets, 2 sheets of 1/4 inch thick insulation foam sheets (such as Superlon), a measuring tape, a pen-knife (scissors won’t do because it gets stained too easily) and a can of cleaning solvent such as WD40 for cleaning bitumen stains.

Firstly, dismantle the 3 pull handle bars. You would need to press the catch on top of the plastic covers before sliding them out to expose the metal clips below.

The handle bars can now be taken off easily by pulling the bar off the metal clips. The metal clips themselves can be squeezed inwards to loosen them and pushed back into the space behind. They can then be retrieved for safe-keeping by putting your fingers behind the roof lining to take them out.

Next, take out the 2 sun shades at the front. These are anchored to the roof lining with screws covered by a thin plastic cover. Just prise out the thin plastic cover with a screwdriver to expose the 2 screws which you can remove to dismantle the sun shades.

The cabin light are clipped to the roof and can be prised out easily with a screw driver:

The Latio’s roof lining is held into place with 3 flushed-looking plastic clips above the rear seat. You need to use a screw driver and your fingers to prise them out one by one.

Next, remove the A and C-pillar covers after pulling down the door frame-edge rubber linings. Yank the plastic covers off their clips slowly and carefully. One of my C-pillar covers being pulled off below:

My A-pillar cover exposed after yanking off the plastic cover:

The B-pillar plastic cover is not easy to remove (too troublesome to take out the seat belt anchoring bolts) so I simply bent the roof lining with my fingers and prise them free them from the edges of the plastic cover.

Once you have removed the A and C pillar covers and loosened the section at the B pillar, you can start to lower the roof lining. As I had alot of trouble trying to remove the plastic studs used for holding the 2 sun shades at the front, I did not actually pull the entire roof lining off (some friends dropped by after I was almost done and he advised that these studs can be removed by pressing a catch with a screwdriver before pulling them out. so ok next time would try this).

However, by simply lowering the roof lining, there is still sufficient space to paste my aluminium bitumen sheets at the front section. If you are doing it yourself, try the suggestion to remove the last two studs in order to release the whole lining.

The map reading lights/sunglass holder is one complete unit that is secured to the roof area by velcro so you simply need to pull the lining downwards to detach the map light unit from the roof surface. See the velcro on top of the black plastic section below:

Once the lining is pulled down, I would use a measuring tape to measure the roof spaces to cut big pieces of the self-adhesive aluminium-backed bitumen to fit the shape of each flat panel between the cage struts.

After cutting two identical pieces, I pasted them together on the floor to get 2 layers thickness (3mm) before transferring them to the underside of the roof. Pat them down (in this case up) with your fist and palms to make sure they stuck well without any air gaps.

Here is a picture of the first double-layered piece pasted on the bare metal of the ceiling. I have to punch a small hole to keep the bitumen clear of the roof antenna’s base:

Mavericks Bitumen Sheets - DIY Car Soundproofing

Here are the rest of the roof panels pasted with the aluminium bitumen:

The purpose of the bitumen sheets is for mass-loading or deadening of the flimsy metal roof sheets to reduce noise transmission via panel resonance. It is not enough to block off direct noise intrusion. For that you would need to put a noise barrier sheet such as Superlon, a nitrile rubber closed-cell foam sheet commonly used for heat insulation.

Thus, before reassembling back the roof, I sandwiched a couple of the 1/4 inch thick Superlon sheets (trimmed to correct size) between the roof lining and the bitumen layers to supplement the fibre on the lining as a noise barrier.

I cut one sheet for the rear section before the cabin light and one smaller sheet for the section after the cabin light ending before the map lights. Although the Superlon sheets are not self-adhesive, no glue is needed as the roof lining would hold them in place when closed back.

The roof metal sheet, which was rather filmsy before the SP, is now very well dampened and has a solid feeling. Some Lations dropped by just when I was about to finish and we did some side-by-side ‘knocking tests’ with a friend’s stock Latio which has not been SP (hehehe. hers’ really like a milo tin can).

It seems to work well as it rained heavily this morning on my way to work and I could not hear any noise from the heavily dampened roof except for the rain splattering sound on the windscreens.

I also observed that on a dry day, the car also seems a little quieter as the dampened roof no longer resonate naturally like a speaker cone via vibrations conducted from other parts of the car when I am driving on the road.

I hope this little guide is a useful start for you to DIY soundproof the roof of your own ride.


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