Easy & cheap water proof roof

So a while ago my headliner fell down, so i re-glued it. Then i noticed that ever time it got wet (rain, snow, mud, car wash) my headliner would fall down even more. Starting from the back and moving forward. So i pulled my headliner to figure out wtf was going on and found water stains on the headliner in the back driver side corner....



After that i started think of ways to seal it all up so i don't have to worry about any more moisture getting in.

This is what i did.


Got about 3 cans of this stuff..


And filled every gap i could find. including the A pillars and all the way around the top. (Side note: wear gloves when using this stuff because if you get it on your hands it WILL NOT come off. I tried fast orange, gas, and pain thinner. Nothing worked. Also if it spills in your jeep it's best to let it dry before trying to remove it... Trust me...) Also, my first idea was to calk it all up. You can see that in this picture.


Once i finished with that i moved on to my roof. The plan was to calk under my roof rack rails. So i pulled it all off.


Then off came the rails.


And then i used some windex to clean off the dirt and gunk, and scuffed up both the roof and the bottom of the rail.


I used some duplicolor truck bed liner to freshen up my rails before putting down a thick bead of calking, stopping at every bolt hole to force some into the holes, but be careful not to put in too much or you'll make a mess inside your jeep like i did.



I was alone so i did this to place the rail back on without messing up the calking i put down. I'd start at one of the ends and get one of the bolts started before putting all of the rail down. Just so you know it'll line up.


After I did the outer two rails i did the same to the inner four, remove, paint, and seal... The whole thing took about 1/2 hour for removing the headliner, 3-4 hours for the foam stuff, and another 3 for the rack rails. But if you had a few buddies to help you could knock it out pretty quick.

I'll update you on how well this all worked out after i get my headliner glued and the next snow storm hits.

i have heard that the spray foam is not the greatest product to use for sealing up against water as it acts more like a sponge. it might keep water out for a while but will lead to more rust and ultimately more leaks over time.

Nice post!
Man that is a lot of work. I just drilled holes in my floor to let the water drain out.

stewie said:

i have heard that the spray foam is not the greatest product to use for sealing up against water as it acts more like a sponge. it might keep water out for a while but will lead to more rust and ultimately more leaks over time.

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x2. I would not advise that you use spray foam on any part of the Jeep that you do not plan on replacing within a year or 2. I used spray foam and bondo to "patch" my rockers. Before anyone gives me crap for this I knew this was a bad idea but I only had a day to get them fixed before needing to get an inspection and leave for college... and I also had to do balljoints, hubs, u-joints, and a couple other things :laugh:

Anyway, all the spray foam did was cause WAY more rust. I did the foam approach because I knew that I was graduating a year or 2 later and would probably be picking up a newer DD to replace the Jeep (which I did) and the Jeep became a toy/project. Now, as planned, I am going to completely replace the rockers with square tubing. They are VERY rotted now, far more than before. The foam acts like a sponge and causes alot of rust issues.

themangeraaad said:

x2. I would not advise that you use spray foam on any part of the Jeep that you do not plan on replacing within a year or 2. I used spray foam and bondo to "patch" my rockers. Before anyone gives me crap for this I knew this was a bad idea but I only had a day to get them fixed before needing to get an inspection and leave for college... and I also had to do balljoints, hubs, u-joints, and a couple other things :laugh:

Anyway, all the spray foam did was cause WAY more rust. I did the foam approach because I knew that I was graduating a year or 2 later and would probably be picking up a newer DD to replace the Jeep (which I did) and the Jeep became a toy/project. Now, as planned, I am going to completely replace the rockers with square tubing. They are VERY rotted now, far more than before. The foam acts like a sponge and causes alot of rust issues.

Click to expand...

Hopefuly no moisture even gets to the foam... We'll see i guess. haha i'm now moving on to see if i can't do something about the hinges and possibly sealing up that gap between the body and the hatch, maybe some sort of rubber flap just to keep out as much as possible. i know it's fiberglass and won't rust but it tends to collect a lot of soggy leafs back there and that part can rust. I've also been thinking of putting that foam in the back hatch for sound deadening.

Regarding insulating foam, I've always been under the impression closed cell foam is better than open cell regarding water resistance.

Any idea what type that spray can is?

nochance9 said:

Hopefuly no moisture even gets to the foam... We'll see i guess. haha i'm now moving on to see if i can't do something about the hinges and possibly sealing up that gap between the body and the hatch, maybe some sort of rubber flap just to keep out as much as possible. i know it's fiberglass and won't rust but it tends to collect a lot of soggy leafs back there and that part can rust. I've also been thinking of putting that foam in the back hatch for sound deadening.

Click to expand...

I have had leaves collect many times and don't have a hint of rust back there. That would be the least of my concerns. From the looks of it you filled all the supports of the roof with the greatstuff? Is that correct? (or at least filled around the openings)..

If you did that I would spend my time covering all of the holes you found which could cause leaks with RTV to keep water from getting in at all. Like you said, Ideally there will be no water getting there in the first place... but I assume that you did this for a reason... and I assume that reason is because you were getting leaks. Put 1 and 1 together and chances are your foam is getting wet.

nochance9 said:

So a while ago my headliner fell down, so i re-glued it. Then i noticed that ever time it got wet (rain, snow, mud, car wash) my headliner would fall down even more. Starting from the back and moving forward. So i pulled my headliner to figure out wtf was going on and found water stains on the headliner in the back driver side corner....

After that i started think of ways to seal it all up so i don't have to worry about any more moisture getting in.

This is what i did.


Got about 3 cans of this stuff..

And filled every gap i could find. including the A pillars and all the way around the top. (Side note: wear gloves when using this stuff because if you get it on your hands it WILL NOT come off. I tried fast orange, gas, and pain thinner. Nothing worked. Also if it spills in your jeep it's best to let it dry before trying to remove it... Trust me...) Also, my first idea was to calk it all up. You can see that in this picture.

Once i finished with that i moved on to my roof. The plan was to calk under my roof rack rails. So i pulled it all off.

Then off came the rails.

And then i used some windex to clean off the dirt and gunk, and scuffed up both the roof and the bottom of the rail.

I used some duplicolor truck bed liner to freshen up my rails before putting down a thick bead of calking, stopping at every bolt hole to force some into the holes, but be careful not to put in too much or you'll make a mess inside your jeep like i did.

I was alone so i did this to place the rail back on without messing up the calking i put down. I'd start at one of the ends and get one of the bolts started before putting all of the rail down. Just so you know it'll line up.

After I did the outer two rails i did the same to the inner four, remove, paint, and seal... The whole thing took about 1/2 hour for removing the headliner, 3-4 hours for the foam stuff, and another 3 for the rack rails. But if you had a few buddies to help you could knock it out pretty quick.

I'll update you on how well this all worked out after i get my headliner glued and the next snow storm hits.

Click to expand...

Why didnt you just seal around the holes?

themangeraaad said:

If you did that I would spend my time covering all of the holes you found which could cause leaks with RTV to keep water from getting in at all. Like you said, Ideally there will be no water getting there in the first place... but I assume that you did this for a reason... and I assume that reason is because you were getting leaks. Put 1 and 1 together and chances are your foam is getting wet.

Click to expand...

That's why i sealed under the rack rails. And tomorrow i'm going to get around the hinges with some black rtv.

bcmaxx said:

Why didnt you just seal around the holes?

Click to expand...

I kinda hoped all the foam would help reduce road noise... And i didn't think about doing the rack rails until after i had put the foam in.

JrTxJ said:

Regarding insulating foam, I've always been under the impression closed cell foam is better than open cell regarding water resistance.

Any idea what type that spray can is?

Click to expand...

I have no idea but i can tell you it is very water resistant. i got quite a bit on my hands and the stuff will not come off. When it dries it kinda develops a film around the outside that repels water like mad. But if you break a piece off it's more like a sponge.

They do make waterproof expanding foam sealant. It's for pond building, black in color, about $12/can last I checked.

Expanda foam is very flamable and if you weld near the area and heat the metal poof goes your XJ.

fubar XJ said:

They do make waterproof expanding foam sealant. It's for pond building, black in color, about $12/can last I checked.

Click to expand...

same stuff.
the black is just UV resistant for outdoor pond applications. i use great stuff in my reef tank and it's fine,no water logging at all.