2005 Grandby Roof Repair Help

[kruss13]

I am in the process to spend the upcoming weekend working on my '05 Grandby's Roof.

I purchased a 2005 GMC 2500HD 4x4 and Grandby together this past summer and have been prepping it for the winter. (See Attached Pic of Camper/ Truck) My primary use for this is as a base camp for my backcountry snowboarding trips and road trips to resorts across the US and B.C.

We have been experiencing some moisture in the front right (passenger side) corner of the cab over area. So much so it at one point caused mold to grow on the front pop up panel. When applying water directly with a hose there is no obvious spot at which the leak is coming from. The Canvas is in like new condition. (previous to me the owner used the camper once and then stored it)

In some forums I've read that by replacing the hardware on the roof many of these problems were solved.

My plan based upon reading some forums on here is to remove all of the original existing roof screws, washers and silicone and replace them with stainless hardware, and new silicone. While I have all the screws removed I plan to repaint the surface with roll on rustoleum paint to repair/ protect the roof surface which is begining to show wear and tear. At the same time I plan to install some yak tracks for a future cross bar install and solar install.

I have a few questions regarding this project that I was hoping to clear up.

1. Is replacing the screws and using new silicone enough of a fix or do I need to remove the side trim and completely separate the two panels and re-seal that seam as well?

2. Along with question #1 should I be removing and replacing the sealant and screws on the side trim at the same time?

3. I have read about ATC using expanding foam in the aluminum frame members on the corners to prevent water from leaking in there and sitting inside there to cause leak issues. Does anyone have any experience doing this? If so can you please share pictures or advice on how to do so.

4. Lastly, being a newb to all this is there anything else I am missing that I need to check while I am doing this?

Thanks in advance for all the help!

 

[Beach]

I would remove and clean all fasteners on the top only, unless you see a problem with the side trim, be sure to check all side fasteners for tightness though. Do not use silicone sealant, use a polyurethane based sealant, 3m 5200 or 4200 are a couple good ones. Be sure to clean the surface thoroughly with a solvent. I put a dab in the hole and on the screw threads also. Be careful not to over tighten. After I resealed mine I found I still had a leak when driving in moderate to heavy rain. The weather strip at the front has a hollow section that seals against the roof when it's down. The hollow section had collapsed over time and did not seal well. Rather than replacing the stripping, I took piece of mig wire and fished through the collapsed section of the stripping. and pulled a length of 3/16(might have 1/4") vacuum line into it(use dawn dish soap as a lube) to reshape the stripping. All has been good since then, no leaks. Also beware of condensation, I leave a small fan running 24/7 to circulate the air inside when rig is not in use.

 

[kruss13]

Beach,

Thank you for all the info!

What sort of solvent did you use to clean the surface?

The hollow weather stripping on mine is flat as well I think I’ll have to do the same.

 

[Beach]

I used toluene, It's a carcinogen, so wear nitrile gloves and stay up wind if you don't have a respirator. I used it because it didn't remove the roof paint. like some other solvents.

 

[craig333]

Lots of threads on here about roof sealing. Be sure to read the ones on what type of screws. Stainless seems good at first glance but apparently not. I coated my roof instead of resealing each screw but not enough time has passed yet to see if its a good long term solution.

 

[klahanie]

^ This year I did this also (complete coat). A more viscous elastomer would have been quicker for me (fewer coats) but it was an easy process and a good alternative to resealing and/or replacing each fastener, imho. I edge wrapped the application to included the side flashing bead and screws - that bead is important (later construction may be different).

Downside is loosing the easy to clean, original, hard surface finish.

my .02


Beach, great idea with the tubing !

 

[kruss13]

Thank you everyone for the feed back!

Beach, again great info.

Craig, I've read through many of these forums you talk about I just needed some clarification so I appologize if I've added to the clutter on the forums.

Klahanie, I've read a bit about using a rubberized coating like that. I think for my intended use I will benefit both in the pocket book and for general use with the paint. I was seriously considering it at one point with the thought of potential added insulation.

I thought based upon what I read that going the stainless hardware route was my best bet, am I mistaken? More info on this is appreciated thank you

My last question in regards to removing the screws involves removing them all at the same time.

Has anyone ran into issues or problems when removing them all to paint the roof?

Should I do it in sections instead?

Thanks Again for all the feed back.

 

[ckent323]

If you can't find a place where it is leaking you may be dealing with condensation.

You may already know the following but just in case:

1) Don't store the camper outside with the mattress in place with the top down. Put the mattress in the aisle. Better yet store the camper inside a building that stays above freezing inside.
2) Heating and cooling above/below dewpoint can cause condensation. I have a hypothesis that moisture forms in the aluminum tubes in the roof, which are hollow and moisture can run down t(inside or outside) to the ends or places where screws or staples penetrate them and allow dripping of the moisture. This is a slow process and is only a problem over some amount of days, weeks or months. I have not proven this theory so I store my camper with the top down and the mattress in the aisle (no room in the garage).

Before I came up with my condensation hypothesis I resealed my entire roof. After cleaning with alcohol, I used 3M 4200 to reseal all of the fasteners on the roof as well as around the vent boxes and around the yakima tracks. The stuff is very sticky and needs to be applied slowly and carefully to avoid getting it all over the place. Using a plastic tongue depressor to smooth out the sealant bead line helps a lot to create a smooth professional looking continuous line.

After the roof sealing I still had a damp spot in the same location as before following several damp and cold or freezing nights. The amount of water is small the worst I have seen is maybe a table spoon on the floor of the over cab bed area and a damp spot on the ceiling.So I suspect condensation. My driveway is sloped a bit but I have not yet tried changing the position of my camper to see if the damp spot moves if the camper is put in a different place on the driveway (slope to the other side for example)

Some folks put an incandescent lamp with a low wattage bulb in their camper and leave it on when it is stored to keep the inside dry. There are other ways to do this as well using moisture absorbing crystals or a small dehumidifier. We leave a large box of baking soda in the fridge and prop the door open. That seems to help too.