Can I use black top roof sealant to re-attach heat shield on my 2006 Ford Focus?

The heat shield between the exhaust pipe and the underside of the chassis is rather large on the Focus. The heat shield is fastened to the underside with studs and nuts. The heat shield ripped around the studs and it is just dangling under the car and making rattling noises.

I am thinking about “gluing” the heat shield back on to the underside with blacktop roof sealant. The highest quality sealant goes for about $10 for a canister at Home Depot. I am thinking if it is strong enough to attach roof shingles to the roof, it should be good enough to hold the heat shield in place.

Do you think that would work? What type of sealant or material should I get? Should I glue all around the heat shield or should I tack it on?
Any suggestions?

No. That roof sealant is flamable.

Either have someone reinstall the heat shield, and if that can’t be done, remove it.


Will not hold up for the heat and the shaking. If you want Macgyver solution buy some braided steel cables thread thru the holes and fasten it. But your best bet would be replacing it or welding the old one back…

Try to get somebody to weld it. I would recommend a couple of long clamps that resemble radiator hose clamps but only for the smaller shields. If you can find some thick mechanics wire it might hold for a couple years. Don’t use coat hangers with plastic coating. They usually have some kind of coating. Glad you asked about (not) using roof sealant.

Use fender washers over the studs and heat shield and put the nuts back on.

Catalytic converters can get up to 1,800 degrees or more in normal operation. Roof sealant wouldn’t stand a chance and would quickly melt or catch fire. This is something you should get fixed the right way.

There’s an ongoing joke in the acvw community that you can fix anything with Henry’s roofing tar.
Maybe it isn’t a joke.

Regardless, everyone knows that great stuff is a better glue, sealant and is sandable and paintable…

Jk btw

Have you looked at what it would cost to have it welded at a muffler shop? I bet it would cost little enough that experimenting with industrial products would be redundant.

I had one loose on my older car about 5 years ago. I took it to the shop that occasionally does work for me, and they welded it for free. Took about 5 minutes. I expect the charge would be minimal to get this fixed, and better than worrying that the car could go up in flames if things get hot enough or depending on the part that’s loose, if you park over some dry grass.

Shield is between body and cat. Grass is on other side.

The shield will fall of when the roofing tar softens as it gets hot enough. Then the tar remaining on the exhaust system might catch fire.