I'm planning on switching out my interior dome light with the dome light that has two map lights so since I might have to take down the headliner to run some wires I was wondering if anyone has ever put fiberglass cloth between the roof and headliner for the purpose of insulation. I don't want to put that foil looking sticky stuff, although I've used the home depot version inside my doors and they work great. I don't want to put that on the roof because I know it will get really hot and I don't want that stuff coming off and stuff. that is why I'm thinking of putting fiberglass cloth inside the headliner. Let me know what you guys think?

 

1) The headliner doesn't need to come down.
2) The headliner is already insulated.
3) Peel&Seal or DynaMat won't come off, if the surface is reasonably clean, regardless how hot the truck gets (until it catches fire).
4) I wouldn't want loose fiberglass anywhere in the truck.
5) We could help you more if we knew what you're talking about. Put ALL the truck's details into your signature as this caption explains:


(phone app link)

 

Here is a link to BLDTruth's recent write up in this forum.
https://www.f150forum.com/f10/sound-...roject-425766/

There are lots of other write up's on this forum easily found by a Google search. https://www.google.com/search?q=Ford...hrome&ie=UTF-8 Many of the threads are about newer trucks but the information crosses over.

There are many products available for insulating and soundproofing our trucks You didn't state what fiberglass mat that you are referencing. You might check out some of the foam products on the current market for comparison. There are foams with or without adhesive depending upon how you plan to install. The best results come from layering different substrates such as a constant layer dampening (CLD) + closed cell foam (CCF) + mass loaded vinyl (MLV). Due to the weight, headliner applications are usually without the MLV.

I've used the Peel n Stick asphalt product from Lowe's in floorboards and truck doors. It helps slow down heat transfer on the floorboards and sound intrusion in both locations, but, I don't feel comfortable with the adhesive & asphalt combination on the underside of the roof so will be using a the Stinger CLD + foam on my headliner in the near future.

There are many brand choices; Dynamat, FatMat, HushMat, BQuiet, Noico, Stinger Roadkill, RAAMat, Killmat,Vibro, Second Skin, etc. Prices vary. Many of these suppliers offer layered products already combined for ease of installation.

Here are a few links:
A local custom autosound shop uses this product line with good results.
https://stingerelectronics.com/catal...ping-roadkill/

Constant Layer Dampening:

Closed Cell Foam:



Good luck with your project.
Jonathan