Here was my car’s fabric headliner before I repaired it:

After more than a decade, the original adhesive that holds the fabric to the backer that lines the roof of the car was failing. The headliner was detaching from the backer almost to the middle.

This is a common problem in aging cars. What’s going on? And how can we fix it?

This photo of the edges by the windows show how the fabric was originally attached to the backer with a thin layer of foam adhesive. The adhesive bond with the fabric breaks down. At this point I can easily rub the foam off the white backer board with my finger.

The backer itself serves the useful purpose of insulation against both noise and temperature. It also protects wiring that runs under the roof to interior lighting and exterior antennas.

Since the fabric is only a decorative finish it could be torn off and the adhesive rubbed off to leave the backer exposed. That process alone would be a project. A complete repair would then involve removing the entire backer, spraying on new adhesive, and rolling the fabric back against it.

I wasn’t up for such a laborious repair and wanted to just reattach the headliner where it was sagging excessively. I decided not to use spray or liquid adhesives after reading too many anecdotes of them failing quickly. They’re very tricky to apply correctly and evenly: without completely removing the headliner and backer they seem likely to flash through the fabric in spots as shown here:

So here’s what I did

For edges I rubbed off the original adhesive and applied double-sided 3M Super Strength Molding Tape right to the edge of the backer. Then I pulled the headliner tight over it:

For the sagging bulk of the headliner I these upholstery tacks:

Twisting these through both the headliner and backer forms a mechanical bond that can’t fail. Applying the tacks in a pattern looks decent, and they can be added as necessary if the headliner detaches elsewhere in the future. Here is how this repair looked when I was done: