roof flex

[S3Customs]

What are some of the ways you guys stiffen your roofs? i have done the extreme style were i stacked mdf and spray foamed the gap. On this project (trailblazer) i want to stiffen the roof but stil be able to put the headliner back in. So im looking for options. I have thought of kerfing mdf or layering 1/4 inch birch ( because it would curve easily) down to the bottom of the roof braces.What adhesive has worked the best for you guys when gluing wood to dynamate extreme. Any opinions would be greatly appreciated.

[Boon]

Aluminium flat stock, expanding foam and urethane glue. Then dynamat over the whole lot.

[BKDAVILL]

second skin

[big dee]

ive had the same problem and i couldnt ever get itto stop.if you find something that works good please post it

[D_man1987]

what I did in one of my rides was first get about 10' of shelf track like THIS

It has like a [ shape that stays rigid. SO I installed it like a "U" by gluing it on with liquid nails the contractor grade stuff. I did 4 of these in the inner side of where the "rain gutter" things on roof of my yukon are.

then I cut a "I" shaped piece of 1/2" MDF that was thinner where the bracing was and stretched the width of the top otherwise. I did this so along the bracing I could still push this section up to fit headliner when I was done.

on the center section of the "I" I screwed directly to the brace using 3/4 screws. then I also screwed screws through the 1/2" MDF to the shelf tracks for more bracing.

then where the front and rear sections meet up to the braces of the vehicle I used ( 1/8" by 2" aluminum slats that were roughly 4" long to mount front and rear braces to MDF. 3 front 3 rear with about 2" on top of MDF with 4 screw then 2" over the bracing with 4 screws on that side as well.

Next step I drilled 3/16" holes in the MDF all about 6" from each other and filled all voids with GREAT STUFF.

let if dry for about 2 days without pounding on it(so it will bond to both sides well), then trim excess foam and spray painted flat black.

If you want you could also do a layer of sound deadener over it but I felt it wasn't needed.

I am running 6-12's on over 10,000RMS tuned to 30hz subs/port both UP doing 154.3db on TL and barely move it.

oh, and you can't even tell that it is under there other than when you push up on headliner from inside it is stiff and doesn't move.