hey jamesW,
I read the sound deadener site.
Question for the asphalt based estuff you used can you smell it when its hot outside?
That seemed to be a thing the guy who did the site claimed.

Thanks

 

I've had mine installed for about 18 months. Last summer, I never smelled it. Most of it is underneath the carpet, but the firewall is covered.

 

Blane, the aluminum backing on the fatmat does a good job of keeping the heat in and the cold out, or vice versa.

If you really want to do a good job, there is another material you can get. You know those silver things old people put on their windshields to keep the sun out? Its like an aluminum backed bubble wrap. That stuff is excellent for heat insulation. We did our basement in that stuffon the cold block walls around the furnace andit definitly made a difference. We have alot left overso I plan to put a layer of it on the firewall just for the hell of it. Its practically weightless, so even if its alittle overkill, oh well. Dont get it off the internet, its overpriced! Lowes has rolls for decent prices. You could probably put it under the carpet too if you like, but I would definitly do the Fatmat and then consider this if you still would like more.
Nic