# Laying MLV on floors



## jyu1210 (Dec 16, 2011)

So I was wondering if I were to lay MLV on the floor under the carpet of my car, will I need adhesive for it to stick on the floor and can I just lay it on, then lay back the carpet on top of it?


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## adrenalinejunkie (Oct 17, 2010)

No adhesives needed when installing it on the floor.


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## Justin Zazzi (May 28, 2012)

Mass loaded vinyl should (ideally) not be in direct contact with the floor, nor glued to it like damping materials. If you can, use a thin layer of closed cell foam (1/8" is good) between the floor and the mlv to decouple it from the floor itself, then you can lay the carpet on top. My car had a separate layer of material just below the carpet and I placed my mlv between this layer and the carpet.

If neither of these are an option, then yes, you can simply lay the mlv on the floor and the carpet on top of that.


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## jyu1210 (Dec 16, 2011)

Hey Jazzi, why would you say that it's not ideal for the MLV to be directly on the floor?


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## Justin Zazzi (May 28, 2012)

If the mlv is in direct contact with the floor of the car which is vibrating, then a portion of those vibrations will transfer directly into the mlv and cause it to vibrate too. If the mlv is vibrating, it is producing airborne noise just like the floor of the car would be, and this reduces the efficiency of the sound barrier significantly.

An analogy would be heat transfer. A thin cup full of scalding hot coffee is too hot to hold. But slip a piece of cardboard around it with Starbucks printed on the side and you can hold it as long as you like. The similarity is the cardboard acts like the closed cell foam. The cardboard provides a (mostly air) cushion between the cup and your hand making it more difficult for heat to transfer directly through.

If you can place any material between the mlv and the sheet metal floor of the car, do it. Otherwise, some mlv is going to be much better than none. Also, don't forget to apply some (about 25% coverage) damping material to the sheet metal if you need it. SoundDeadenerShowdown.com has great information about all of this, you can read more about it there.


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## jyu1210 (Dec 16, 2011)

Ok, so I looked into it some more and thinking about picking up some Ensolite. The Ensolite has an adhesive backing so would I place the mlv on the the adhesive part then lay the ensolite down with the mlv behind it?

Does this apply the same to doors?


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## Justin Zazzi (May 28, 2012)

Looks like a good plan, but you could put the adhesive side of the Ensolite down towards the sheet metal if you like (many prefer this method so it does not shift around, and also because it can create an air seal against any openings in a door skin, etc). This is what the layers a sound treatment might look like:

*(inside of cabin)*
--trim panels, interior plastic pieces, carpet, etc
--one layer of damping tiles at 25-50% coverage attached to the back of interior trim pieces if really needed (Raammat BXT II, Hushmat, etc)

--one layer of massive barrier, attached to foam layer below it (mass loaded vinyl, anything 1lb. /sq. ft.)

--one thin decoupling layer of lightweight foam (Ensolite, closed cell foam)
--adhesive side of the decoupling material attached to the sheet metal or damping tiles

--one layer of damping tiles at 25-50% coverage (RaamMat BXT II, Hushmat, etc)
*(outer sheet metal of car)*

This generally applies doors too. You would do about the same thing but need to apply damping to the outer door skin (where the outside door handles are attached), and the inner door skin (where the plastic door card attaches to), and seal the inner door skin using a vapor barrier like Ensolite. Some people will skip the massive barrier in the doors.

RAAMaudio has a good writeup of how to do all this, give it a read here -> How-To


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## thomasluke (Jun 10, 2011)

Jazzi said:


> Looks like a good plan, but you could put the adhesive side of the Ensolite down towards the sheet metal if you like (many prefer this method so it does not shift around, and also because it can create an air seal against any openings in a door skin, etc). This is what the layers a sound treatment might look like:
> 
> *(inside of cabin)*
> --trim panels, interior plastic pieces, carpet, etc
> ...


Before you go any further you should read this Sound Deadener Showdown - Your Source for Sound Deadening Products and Information


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## Genxx (Mar 18, 2007)

^^^I second his reading suggestion.


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## jyu1210 (Dec 16, 2011)

But if I were to apply the ensolite and mlv to the doors, can I not use the adhesive side to the door because then it would be a pain to fix any arising problems to components in the door. I was thinking to apply the ensolite adhesive to the mlv then use velcros to attach the deadeners to the door panel instead of the actual door itself.


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## Justin Zazzi (May 28, 2012)

The velcro approach is very savvy if anything in the door should need service in the future and is an excellent choice for most everyone. However sound will transfer through the smallest of air passages, and the tighter a seal you can make against the door the less noise will leak through. It is a tradeoff. Do you want something that is much easier to service (velcro method) or do you want something that is a much better sound barrier (tight air seal)?

You could get the best of both worlds by using the contact cement sold by sounddeadenershowdown.com ... I have used it in my doors and it creates a very solid seal that is also very easy to remove and re-install.

I'm not saying go crazy and glue everything, just trying to show the pro/con of each method so you can make the choice that works best for you.


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## Justin Zazzi (May 28, 2012)

Sound Deadener Showdown | Your Source for Sound Deadening Products and Information

Also, a third recommendation for reading what is written here. There is much more information he is working on now that wasn't available earlier when I first found his site. He knows his stuff.


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## Catman (Mar 18, 2008)

Under carpet I HIGHLY recommend Reflectix ....it is a double layer of alumanized mylar bubble wrap that is used in the building trade. It is great for decoupling MLV and it provides thermal and acoustical properties. I have found it to be FAR better than Ensolite or any other product. It is cheap and light as well.


>^..^<


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