Insulation sound deadening

Well, your choices really are limited to about four options.

1. Dynomat or similar product made for cars, all of which are expensive
2. An OEM style mat
3. The roofing stuff you mention, which I have seen used, but it's not as effective as you might think and it is heavier then the stuff made for cars
4. A spray in sound dampener

Use a ceramic brush on material, like Lizard Skin. Insulate against heat and noise. No gaps. Not too heavy. It's easy to apply, but takes time. I brushed on a coat a day for 4 days. Then just glue your padding and carpet on top of it.

Never heard of this brand before, might even be worth a look for me when I redo my truck. One think I did notice is the price, if the OP doesn't want to buy Dynomat, which would run him around the same price range (depending on source of purchase) I'm not sure he would buy this. Who knows though.

That alone won't really give you a large amount of sound dampening as that is not what it is really intended for. It will provide some, simply because it will cut down on the resonant frequencies of the vibrating metal panels. There is a spray product that is an undercoating/sound dampening that I have used, bought from Checkers that works pretty well.

One think to note about spray dampeners, is that it takes layers of spray to get the effect you can get from one sheet of the mat style. IIRC most sprays require about 3 - 4 complete coats to be completely effective.

Thanks all. McMaster-Carr has a well known mat that is like the original Dynamat but far cheaper. The panels do need to be dampened with a heavy material to keep from vibrating. An absorber of some sort must also be used. Price is a point with me as I'm not employed. I do have some income coming in, but only enough to pay utilities bills and the like so price point is imperative. Wnats don't outway needs. What I found that is working pretty well is duct insulation from the box stores. It's a self-adhesive foam with foil covering. It has some weight so dampens and since it's visceilastic foam it's an absorbant as well. I drove around today with the interior still out (drivers seat only as I took the headliner in to get recovered. Roof, rear cab and rear side walls are treated with 2 rolls of this tuff. I also shoved a one foot peice of standard home insulation in the cavites on each side. It's quiet! Still a lot of noise coming on from the door panels and floor by comparison. I want to get some more stuff up under the light weight foam the factory uses under the dash. When the carpet goes back in along with the seats and headliner, it should be that much quieter. It's amazing how loud the truck is with the interior out. They use it as sound deadening vice just a seat to sit on. There is nothing behind the rear seat. There is a factory applied something hard to the floor in spots as well as the side panels. (4 inch squares or odd shaped sizes here and there in no particular order)

I called a local industrial supply place looking for closed cell rubber or neoprene and when asked what I wanted it for, the man said go get the DIY bedliner. He used it on his jeep and was quite happy with the outcome.

I read a post on a car forum site where a man had mixed concrete patch with the liquid roof repair stuff with great results. Just something I read.

I talked to a local shop. Their experience has been regular dynomat doesn't do much, but the extreme (which is visceolastic foam) works well. Since the factory already has dampening taken care of, I'm looking for absorbtion material; heavy dense closed cell foam of the type normally used in audio apps. The duct insulation seems to be the ticket for my price range ($14 for a 1 x 15 ft roll; doesn't go far). There is an ebayer selling 1/4 closed cell neoprene in Ca for pretty cheap. It's $25 for a full sheet 42 x 72 inches. I could place that on the floor but it might take up too much room and the carpeting not fit back into place. I may add the duct insulation in spots as well as stop by a carpet shop for a pad. I'm going to get the foam up under the factor's foam as far as I can. I'm not removing the dash toget behind it, that's for sure. LOL Blessings, John

Here's something you might like reading.