roof insulation
 

What are some opinions about modern roof insulation to use before I put on the headliner?

George

I put dynamat under mine. Covered it completely 12 years ago and no problems since. Added bonus of stiffening it up a bit as well.

Thaanks. No probs with heat in the summer on the roof?

george

Firebird Central has a product that acts as both a constrain layer (dynamat) and an insulating foam attached. It's inexpensive at a bit over 50 bucks. I used this stuff on the roof of my bird and as an added heat barrier on top of my dynamat over the muffler locations and in front of the differential.

The kits are from Flatline Barriers.

Thanks
George

I used Dynamat knock off (Hush Mat I think) on my 64 hardtop; easy to work with and no problems with heat.
I think it improved the quietness in the car

Missed this.

If you are trying to knock down heat as well you need an insulation product. Dynamat is just a constrain layer. It's purpose is to stop sympathetic vibration in large, flat panels. It offers little in the way of insulation.

If you want the ultimate in sound and heat/cool control you'll want a constrain layer like the dynamat product, followed by an insulating product like that Flatline Barrier I mentioned and then to help control sound a layer of mass-loaded vinyl. Then put your headliner in.

That gets heavy and more expensive though. It really depends on what your needs are. If you're not worried about performance and want a Cadillac type experience, definitely do all three.

A mid-level treatment that is more for vibration and heat would be the matt product and the insulation product.

low level, cheapest and lightest would be just the insulation product.

The insulation product that is used in the factory is a think fabric like material and is probably meant as a heat/cold insulation more than anything to do with vibration. So even that Flatline material is going to be an improvement over factory as it has both constrain and insulation properties. The stuff is quite light as well, if you're concerned about adding a lot of weight high on the vehicle.

I like flatline, its light, and easy to put clips through for the headliner bows. Dynamat Should be on a flat surface. The roof is all perf. (Inner roof) and not a solid flat surface. While it can help, its not really the best these days. Keep dynamat in the doors and floors though.

Dynaliner
 

Check out Dynamat’s Dynaliner for insulation. It’s a high density foam insulation and recommended by Vintage Air. It comes in a variety of thicknesses. You would apply that after the regular Dynamat.

I just did my firebird's roof. A buytl product called Noico against the steel roof, and then a 300 mil foam product by Siless on top of the Noico. It wasn't expensive. I can rap on the roof with my knuckles and it really cut down the noise.

How well do these products stick to the roof? Seems like if the heavier products came loose on a very hot day it would not be good. Do the headliner bows help support it?

FWIW....going to use Fat Mat on mine.

Just bumping to the top. Just put the Dynamat knockoff, Siless, on my floor a couple weeks ago. I really liked the product...thinking about trying their slightly thinner line on the roof of my car. Curious what people are going over the constrain layer with. Thanks!

I think the better way to ask this is, has anyone ever had a butyl based product fail to stick to their roof in the hot sun? I would like to know too.

I know Dynamat is not the only game in town. I use Damplifier pro my self. I don't think it takes much to roll out some butyl and put some kind of tin foil on one side thus the reason for so many variants of the product.

At one time and maybe still today people were getting some roofing products cheap from the local building supply stores. I recall reading horror stories of this stuff failing and ruining headliners after they were installed. I don't recall any time reading about a butyl product doing that.

Yeah, the stick of the product failing is something that definitely concerns me, especially since this is in a wagon and headliners are becoming a little harder to find at times. I’m hoping the bows help hold it up, and even if it did unstick a little it wouldn’t completely wipe out the headliner

I used Dynamat, foam, and mass loaded vinyl on the floors and other areas on my 70 Formula. However, I did not put Dynamat or anything else on the roof because I was afraid it would not hold up here in the AZ desert, and didn't want to risk having to redo the headliner. Even if it didn't fall, I was afraid the adhesive/butyl might seep past the tape or stain the headliner if someone pushed up on it.