We're going to install new carpet in the wagon as we reassemble it after paint. I'd like to install Dynamat on the floors for sound deadening purposes. Has anyone run into problems with carpet fitment after installing Dynamat or other similar materials?

i had no fitting problems on my 70 runner,if that helps

Nothing that was'nt the carpet's fault in the first place... ..Just keep it tight as possible around any contours and it should be fine....I was shocked at how heavy that style matting was when I first used it...Adds alot of weight{and money} to the project fast...But does a good job for what it's intended...I still use it in some applications but if weight is a concern you might want to look at alternative materials...

Most carpets have a lot of excess that needs to be trimmed off so you should be good with the Dynamat. I did mine with no problems.

The sill plates and kick panels will be a bit harder to (re)install

Anyone using this on a 4-speed car around the hump? Seems to me if there was going to be a fitment issue, that really where it might start to rear it's ugly head...

on my 65 dart 4 sp I had plenty of room on the hump. "legendary" carpet iirc/dynamat

I used just enough Dynamat to dampen the resonnation of the panels, when I hit them with my hand. As you can see, the entire panel does not have to be covered. I did cover the firewall area completely though.

...and then covered as much of the panel with The Insulator as would not interfer with the intallation of the door panel being sure to seal the edges and openings with foil tape.

I did the entire interior of the car like this top, sides and floor and had no problems with fitting panels or carpet.

Once the interior was all back in, you can't even tell the stuff is in there. I used a double layer on the floorboards, but it doesn't feel like it when you puch on the carpet etc. It really is amazing stuff.

Is this the stuff you are talking about and did you get the 2ft wide or 4ft? http://www.aircraftspruce.com/catalog/appages/insulator3.php

My camera was misplaced when I did the floor, but it was comprised of a dozen or more separate pieces to make one solid sheet. It fit the floor like it was molded to it when finished and could be lifted out in one big piece, and sealed the entire surface of the interior.

I also like to tape all the edges to keep the edges clean looking. The black tape you see here is Gaffer's Tape. The stuff they use in the film movie industry. It's water resitant, durable and sticks well. I also use that foil tape they sell at Home Depot etc.

Ok, so you didn't actually spray adhesive to the back of the insulation. Except for the roof, right? It looks like the 2ft sections are sold out since I can't get that right now. How much did you end up using?

having done this kind of thing to a bunch of cars, ill give a few tips.

1. don't buy name brand dynamat. its ridiculously overpriced for what it is. i use http://www.mcmaster.com/#catalog/117/3497/=fqjmp1 the plastic 10% sheets. works very well. use a heat gun and J roller to work it in tight to the sheet metal. prep the surface, even if freshly painted, with a pre-painting prep. you want it as clean as if you were about to lay down a top coat of 100 a gallon paint.
2. you only need to do about 80% of the interior. the last 20% really doesn't get you any noticeable results. i use the thump method. if i hear a tinny sound, a vibration, an oil canning, etc,. anything other than a dull thud, it needs it. if,m like on the roof of my truck, theres a gap between a brace or other piece of sheet metal and the panel, work the sheet onto the gap. wit will eliminate the rattle.
3. use the stuff to cover over holes in inner structure. after you get the outer surface of the door done, do the inner structure in its entirety. you'd be SHOCKED at the sound reduction. same in the rear quarter and sail panel openings.
4. do the stuff under other bolt on parts. even when things are fastened sown tight, they still vibrate and rattle going down the road due to chassis flex.
5. cover it over with something like what has already been discussed. i prefer to put the foil side down, and glue it. adding mass to the large stamped panels in our cars really helps. do this in all the areas you can. especially the roof, firewall, floor, and trunk divider.
6. i also tend to use a third layer of insulation. i use the foil bubble wrap they sell at Lowe's as a final layer over everything. did this in my half ton, and it created amazing results with the heat and AC functioning.

i have only ever had one issue with doing this kind of stuff, and thats on a 79 corvette that i just finished. the carpets for those cars is notorious for being ill fitting (due to the production tolerances on the cars, and the various mid year changes, etc). still easily workable. just a little less defined and form fitting than i prefer. but i honestly think that was the carpets fault. on that car, due to the carpets, i only did the "dynamat" and the bubble wrap. not enough room for anything else.

a good way to estimate how much material you need is to take a tape measure and measure the various big areas of the car, rounding UP to the nearest foot. so say that you have a trunk 54X61 inches. thats 20 square feet rounded up. (5ftX6ft) reason you round up is to account for contours, mis cuts, etc. you'll wind up with some left over, but its a lot better than running out.

lastly, look at your carpet choice. stockinteriors.com has what they call the mass backing option. this is similar to what GM started doing in the 80's on their carpets. its about 1/8 inch of rubber bonded to the backs of the carpets. amazing sound reduction there as well.

hope i gave you some solutions. not all that expensive when you add it up, but labor intensive. worth every minute, though. my duster has 400HP at the wheels, with 3 inch exhaust. its as quiet as my wifes stock 2002 Subaru legacy GT wagon on the inside at 65. except for the wind noise from my windows. (still working on that solution)


Michael

You can buy Dynamat Extreme bulk packs from Amazon dot com for about 1/2 price with free shipping. At that price, it's hard to beat. I used 2 bulk packs in my last car.