Insulation mat under carpet Topic is solved

Post by **Clemens** » 10 Jul 2018, 15:58

So today before putting my 95 into a shed I noticwd that the passenger side front footarr was soaked. The worst part is of course the noise insulation under the carpet. I need to pull that and let it dry outside the car. So here is the question:

Does that insulation mat run across the center tunnel (undernearh the radio /climate console) in one piece or is it two pieces? I saw that it ends right in front of the front seat and goes up the firewall (how far?) Snd then underneath the black plastic cover that hides the heater core.
If it is one piece that spans from door to door i might have to cut it.

Post by **abscate** » 11 Jul 2018, 04:29

I had to cut mine in 2013 to remove it and wash the coolant out of it.

Just cut with a sharp knife, make black marks To aid alignment, then duct tape it back together

It’s really high quality stuff, well fitted

Post by **Clemens** » 11 Jul 2018, 06:04

Thank you!

Post by **mrbrian200** » 11 Jul 2018, 07:06

Once that stuff gets wet/soaked, it's sound absorption properties diminish never to fully return. I would consider laying a 1/4-1/2 inch thick additional sound barrier, either a rubberized or dense memory foam type material, underneath to compensate.

There are thinner mats/liners that stick directly to the sheet metal, either self adhesive or applied with headliner adhesive, used by high end professional audio installers to tame down interior panel resonances and help prevent outside noise from being transmitted into the vehicle interior that are less likely to interfere with refitting the carpet. Dynamat is one example of a company with a range of suitable products specifically made for automotive use, but they tend to be relatively pricey compared to a more universal material, such as a flame retardant carpet underlayment/pad from the carpet store which for this purpose would probably work fine.

Post by **Rattnalle** » 11 Jul 2018, 07:46

The soft carpet is a felt carpet made to absorb sound. Then beneath there should be a few pieces of bitumen or other dense material to absorb vibrations. Both do their part.

Post by **mrbrian200** » 11 Jul 2018, 11:07

It's the 'bitumen or other dense material' underneath I'm talking about. It absorbs lower frequencies such as tire and road noise. It has a tendency to compact/fibers bond together when soaked and never really fluffs back up. If road noise seems noticeably louder than you remember after drying it out this is your problem. Replace or 'augment' to get the noise level inside the car back down.

Post by **Rattnalle** » 11 Jul 2018, 11:13

mrbrian200 wrote: ↑11 Jul 2018, 11:07 It's the 'bitumen or other dense material' underneath I'm talking about. It absorbs lower frequencies such as tire and road noise. It has a tendency to compact/fibers bond together when soaked and never really fluffs back up. If road noise seems noticeably louder than you remember after drying it out this is your problem. Replace or 'augment' to get the noise level inside the car back down.

The dense material I'm thinking about doesn't absorb or react to water in any way. It's bitumen (ie asphalt) or butyl rubber (think thick bicycle tube) usually. You can drown the stuff and it doesn't care.

On top is other stuff that will absorb water and I can see this getting less effective if soaked and compacted. Adding another layer should be relatively straight forward while putting the original back in after drying.

Post by **Clemens** » 11 Jul 2018, 13:58

Yeah, it's the yellow foam and the felt carpet being soaked. I can see the part of noise absorption being reduced due to water. It might break down the structure. Thw butyl or bitumen os underneath glued to the floor. I'm thinking thw felt carpet should dry on it's own. The foam carpet wirh the rubber top needs to be removes IMHO. I will cut it out and let it dry I guess. Less hassle than remocing it completely.

Post by **abscate** » 12 Jul 2018, 06:24

I had a gallon of coolant in mine - I removed it, soaked it, and actually filled the metal floor with water to get rid of the coolant - SWMBO is allergic to EG and it makes her sneeze, so removal was required.

I didn't notice any sound difference. High quality materials.

Post by **Clemens** » 12 Jul 2018, 16:39

I cut the lower mat today and pulled it out. Once it is dty i will put it back in and maybe ducktape it. Should be fine. Thanks for all your input