How do you make a long lasting leak repair to an RV

[ahegewald]

The sun causes cracks, the movement towing a trailer and the frame flexing causes cracks. The manufactures know this yet they don't design a roof seam that overlaps the edge of a roof and create a seal under the joint and on the outside upper wall of the RV...not on the roof. Come on guys?

My Sprinter has the flex liner and pools of Silicone and some sort gray mastic semi soft crap that has cracked and lost its bond.

Should I remove the gray mastic and just put clear silicone over it so I can see in the future if the crack has reopened?

How often do you replace and check your roof joints?
I am forced to store my outside... which is harder on it I know.
I bought a $550 cover only to have it ripped to shreds the first winter.
It didn't not seem to protect my RV from gaining moss and protection from the Sun. Wasted money. I think White PVC tarp with straps and bungy's would done just as well. My goal is to block sunlight and keep the rain off the roof.

Now both of my rear back corner roof joints are soft from the water pooling and leaking down the back liner cap and making that upper wall soft too.

RV's are alot work...if you can't have them covered...my advice sell them after you pay off your loan and get a new one...skip the maintenance crap.

[busterbrown]

I agree, RV's are alot of work. Especially as they age. You can mitigate extensive repairs with diligence on routine roof maintenance. As I've said before and I'll say it again, a little time and a tube of dicor now will save you big headaches later. My 3 year old coach (4th seasons of use) will see at least 1 tube of new sealant each year. Already used 4.

[Frank G]

No silicone on the roof, your RV dealer will have dicor products. You Tube has many video's on roof repairs including how to identify the different roof membranes.

[sourdough]

"Covering" the roof is beneficial, but not with a cover..IMO. Some folks use them and they probably work elsewhere but we have winds constantly in spring and fall that are high - 25-30mph steady, gusts to 40-50mph. 2 weeks ago they were clocked at over 80mph with a very generous helping of dirt (which we always have). The cover only ruins the trailer finish then disintegrates as you found out.

The roof is VERY maintenance intensive. It can be the horror of horrors if you neglect it and let water start coming in from tiny, unseen, unmaintained areas over a long period. You (or someone you trust) has to be on it at least once, preferable at least twice, a year looking at every inch of the sealant around the end caps, clearance lights, edges, AC, vents etc. You just have to or end up with "soft" spots or worse.

Don't use silicone....don't. Use the proper sealant for your roof; I use Dicor. It comes in leveling and non leveling variants depending on what you are going to do. Easy to apply...no muss, no fuss to me. Use it liberally as busterbrown said.

Looks like the trailer is 9 years old. What kind of roof mtce. has been performed? If the sealant is dry and cracked and you see silicone someone has tried to "repair" it improperly. If the sealant is dry, cracking and peeling; see the above statement.

You need to remove all the sealant that is cracked and peeling; generally not too hard; grab a loose end and start pulling if it is dry as it sounds. It may break but just get another end loose and go again. Get is all off if possible - I use a small plastic spatula if it seems it might come up, if stuck like crazy, leave it alone - don't tear the roof membrane. When it's all up clean with alcohol - I use at least 70%, 90 if I have it. Rub it and saturate it to get it clean. I've used other products but some will harm the roof so I now stick with the alcohol and it seems to work OK. Apply the Dicor (or whatever) liberally with a caulk gun (leveling on the roof which sounds like your problem). Make sure it covers all the seams or breaks and let it cure. You can use small amounts on lengths of good sealant that have developed a small pin hole or crack. If you do so the sealant should be pliable, fairly soft and not peeling. They make different colors so pick what fits.

Silicone....the bane of RV maintenance..generally. It is difficult, if not impossible, to remove. On an RV where you are constantly repairing, removing/replacing sealants etc., putting something like silicone on a surface just assures that you will have problems the NEXT time you have to come around. Hopefully you don't have much and you can get if off to a point that you can apply the Dicor (or?) and it will adhere. I don't think Dicor will adhere to silicone but I have not refreshed myself on that.

If nothing has been done on that roof for 9 years I can assure you that that is a LONG time to go without a comprehensive roof check. I wish you the best and post back with any situations you encounter.

[Ken / Claudia]

The roof needs inspection at least every year and at that you likely will miss problems until you see them inside. I spend yesterday, about 6 hours on my RV roof doing anual cleaning and maintenance. I think this is my 7 RV, all lived their lives outside. Some I tried cloth or plastic covers and do not think much about them. I was lucky, no need for more decor yet this season.
I also maintain my homes and spend 4 hours on this home's roof last week. RVs need more maintenance than a stick built home. As you have found and the reasons you listed are why. But, maintenance is just a fact of life if you want your car/pickup, rv, home, boat to last.

[owen4it]

You've gotten some good advise here, I'd go one step further and say the longest lasting repair is with Eternabond tape. I had used the Dicor lap sealant on the seam of the front cap for my fifth wheel and still had a leak... I cleaned it with acetone and put a four inch wide piece of tape the full width of the camper and finished it off with more Dicor and it has held up wonderfully. I also got a little too close to a large branch and then backed up... the sharp roof plywood against the branch made a nice cut about two feet long on the corner. I again used the Eternabond tape and Dicor around the edges and no leeks since. I think this is the best long term repair there is. I also don't believe a cloth cover is worth the money, they give the critters something to climb up on and hide what's going on with ice and snow.