Thursday, June 1, 2023


Maintaining and replacing insert molding helps avoid damage, mold and rot

By Dustin Simpson, California RV Specialists
It’s important to make sure your RV is taken care of, so please don’t forget your insert moldings.

Part of this means checking to make sure your roof trim is in good shape, as well as side seams and front and rear moldings. No one wants to start a vacation only to find out that the roof and body were not sealed properly. Unless you visually check the insert moldings, in most cases you will not see the water damage until it is too late.

Why is insert molding important?

It helps to keep the moisture and other elements out of your RV by sealing the edges of the roof, body, and the front and rear seams. This is a very important step for you in weatherproofing and protecting your unit.

When water gets past this seal screw cover, it can cause serious damage, spreading through the unit and inviting the growth of mold, rusting screws and causing dry rot.

California RV Specialists recommend that you replace the insert molding as needed every 2-3 years.



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Karen Powell
1 year ago

Thanks for so much great easily understood rv info! The insert molding for seams discussed above in this thread, I’m understanding needs replacing every 2-3 years, sooner if showing signs of issues. We have a 2018 Venture Sonic Lite 169VRD. It has a solid one sheet roof, bumper to bumper and seams are on the sides and of course the skylights, bath exhaust and ac unit have sealants. Does this also follow the 2-3 year rule, if not needed sooner for insert moldings? We have also wondered about adding a drip rail, gutter, for the ac , or rain, along the rear upper exterior wall, just to deflect water from the running lights and window, or draining down into the lower seams.

1 year ago

We have a 2000 Crossroads All American 5 th wheel. 1st year we bought her I took out all screws under inserts, one at a time squirted silicone into screw hole then put in stainless screws, then installed vinyl insert. Since then the old girl’s been to AK and back 15,000 mi., Fl 3 times 9000 mi., PEI and NS 5 times 6500 mi. Brought up using PM. Still no leaks Thank God.

1 year ago

Highly recommend checking every two Years. I know from experience. Had a missing screw under trim from factory. Major leak. Mounding is cheap and easy to replace

Bill kocken
1 year ago

This article doesn’t tell us how to fix the molding if there is a problem.

1 year ago
Reply to  Bill kocken

That’s easy, just call your local RV repair shop and schedule to drop off your rig in April, then pick it up in December, find out they did a crappy job, Google how to do it yourself then re-do it properly.

Tom Hodge
1 year ago
Reply to  Brian

LOL! True

Bob M
1 year ago

The insert molding is another piece of garbage RV manufactures use on RV’s that don’t last. Had a two year old Keystone Outback and the insert molding cracked along the roof.

Greg S
1 year ago

I’ve had some tell me to replace the screws with stainless steel screws to avoid the rust issue. For me, seeing the rest from a screw is the first sign of a water intrusion issue.

Bob p
1 year ago

The first time I’ve heard of that.

George Glovier
1 year ago
Reply to  Bob p

If screws any where RV are rusting you have a moisture problem in that area.

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