Latio Floorpan and Boot Soundproofing

After doing back-breaking DIY soundproofing of the floorpan on my 2 previous cars, I decided to engage experts from the car audio industry to do it for my latest ride this time.

I completed my Latio floorpan (labour $160) and boot (labour $40) soundproofing at Sin Kit Audiophile (Toa Payoh Industrial Estate) in June 2005 using my own supplied materials such as the 20m x 1m roll of vinyl-backed bitumen sheets and closed-cell insulation foam sheets (such as Armaflex, Aeroflex, Insuflex, Superlon etc.).

The road noise from the Aspec DB tyres at highway speed is now much more muffled and the ride is more refined. At lower speeds, running over humps and rough roads almost produced no noise in the cabin other than feelable bumps from the suspensions. I would say there is a reduction in road noise of at least 50%, not bad from a car already designed to be quiet from ground up.

Here is a picture of my floorpan before the soundproofing. As you can see, there are already small patches of factory-installed bitumen sheets sprayed painted to my vehicle colour on the floor board:-

My floorpan with 4 layers of 1.5mm bitumen sheets pasted on to dampen vibrations and lower the road noise resonance frequency:-

The stock Latio soundproofing comes with these 5cm thick styrofoam plates. It was quite a suprise to see these styrofoam but we decided to put them back after pasting the bitumen layers on the bare metal below:-

More pics of the 4-layers bitumen sheets applied on bare metal on the floorpan and under the rear bench:-

The workers next laid 1/4 inch thick Armaflex insulation foam sheets on the styrofoam and bitumen sheets. The Armaflex sheets serves as an additional sound absorbing layer:-

The insulation foam sheets laid on top of the bitumen :

Next: The boot soundproofing. The sidewall carpets, boot floor cover and spare tyre taken out to reveal naked panels with small patches of factory-installed bitumen pieces:-

The spare tyre well, boot sidewalls and rear wheel arches were generously pasted with an estimated 3 to 4 layers of 1.5mm bitumen dampening sheets. That used up my entire roll of 20 sqm bitumen sheets:-

A layer of insulation foam sheet is then overlaid on the bitumen to act as a noise absorber:-

Overall, I would say the skills level of Darren's workers is good and they are meticulous. It was certainly very hard work as it took 2 to 3 workers almost 7 hours to complete all these.

As with any soundproofing project at ICE shops, before you start, make sure you come to an agreement with the boss on the numbers of layers you expect to have applied and then hang around to ensure it is done as agreed. I have forummers who told me they were cheated on the work done (not at Sin Kit) previously as they "trusted" the boss. They had only one thin layer of bitumen pasted when they finished, with the remaining bitumen thrown or returned back.

Next project: DIY door and roof soundproofing using a new type of aluminium-foil backed bitumen sheets (called Solar Shield, very similar to Accumat Hyperflex but many times cheaper) and Armaflex or Superlon insulation foam.