roof edge trim sealing

[Rochester Coops]

What do you guys use under your (aluminum) roof edge trim? Silicone, butyl tape, something else? Do you use the same sealant (or what) under your roof top vent?
Thanks, definitely want to avoid a leak.

[48Rob]

RV roll putty/putty tape is the most commonly used material.

It is soft, flexible, and mostly non hardening.
When the time comes to remove the trim or vent, it will be easy as the putty is not an adhesive, nor is it sticky or messy.

Rob

[planovet]

I used the same as Rob. Very easy to use.

Here it is on my vent lip before I installed it:



Handling tip, if it's hot outside put it in the fridge for a while before you use it. Makes it much easier to handle.

I also used a dab of silicone in the holes that I drilled for the screws. Just a little extra protection.

[grant whipp]

+1 for what Mark & Rob said ... try to get the grey or black stuff ... the white & off-white stuff dries out and chalks up and ends up being worthless.

If you are using RV style Roof edge Moldings (the kind with the vinyl insert), then use the RV Putty Tape ... if using the traditional roof edge molding (with the screws exposed), use a bead of latex caulk in the corner and a bit around each screw hole.

God luck, and as always ...

CHEERS!

[Rochester Coops]

Thanks guys!

[Rochester Coops]

Has anyone used straight silicone? I have that here, would have to go looking for the tape.

[48Rob]

You can, and some have, but it is a bad idea.

Paint won't stick to it, it attracts dirt, it is a glue, so removing the pieces in the future will be near impossible without destroying them.
There are better ways to save a buck or a few minutes.

Rob

[Rochester Coops]

I appreciate the advice, but I service/repair windows and doors for a living and we glaze glass with it all the time. Aquariums are sealed with it. That said I agree with you that I would never surface 'caulk' with silicone. Water-sealing 2 surfaces that are held by fasteners is totally different. Has anyone used it for sealing their trim?

[Rochester Coops]

re-read your post, guess you're not arguing its sealing ability. That was more what I was wondering, how it held it in this application. But I see you're point about removing it in the future. I didn't know the tape did not really get sticky. the only butl tape I have used in the past was real messy and would be worse than silicone to try to remove.
This stuff must be different.

[48Rob]

Very much so.

It is designed for just these types if applications; for vents, trim, windows, doors, etc, that at some point in the future will need to be removed.

I agree silicone is a great product, for specific purposes, and performs very well when applied to properly cleaned and prepared surfaces.

In the vintage trailer repair world, and likely others, silicone is a much disliked product, because so many do it yourselfers grab a tube to smear all over everything in an attempt to "fix" leaks and to use for purposes that other products do a much better job at.
It is very difficult to remove silicone thus applied.

If sealing the edge of the applied RV putty tape/ the space between the body and trim, is desired, a product called OSI clear gutter seal works very well.
It stays clear, doesn't attract dirt, is very flexible, is paintable, and is removable.

Rob

[Jdhiker]

The grey RV tape is like 3/4 wide. Would you put it side by side to lap over the edge a little for the roof trim to seal the side wall edge too?

[DMcCam]

The grey RV tape is like 3/4 wide. Would you put it side by side to lap over the edge a little for the roof trim to seal the side wall edge too?

Hi Jim,

The butyl RV tape will squish down a lot. I put two layers side by side overlapping the roof edge then put the trim over it and screwed it down. It seeped out under the roof edge trim all summer on the sides. I'd take a plastic edge tool for cleaning grout and clean it up periodically. The stuff expands with heat quite a bit. It was probably overkill but I know I've got a good seal.

All the Best,

Dave

[Jdhiker]

The grey RV tape is like 3/4 wide. Would you put it side by side to lap over the edge a little for the roof trim to seal the side wall edge too?

Hi Jim,

The butyl RV tape will squish down a lot. I put two layers side by side overlapping the roof edge then put the trim over it and screwed it down. It seeped out under the roof edge trim all summer on the sides. I'd take a plastic edge tool for cleaning grout and clean it up periodically. The stuff expands with heat quite a bit. It was probably overkill but I know I've got a good seal.

All the Best,

Dave

Perfect. That's exactly what I will do! Thanks Dave

[Campin' Texan]

I did the same as everyone else. I put the trim on, started a screw about half way in each hole, took off the screws and trim, put a dab of silicone in each hole, put RV tape down, then screwed down the trim. Made a great seal. A little of the tape came out the side and the screw holes. I don't think I have to worry about water getting in.
This is the cheapest place I found the tape in black. $4 for 30 feet. http://www.factoryrvsurplus.com/products.php?product_id=50

[jonw]

FWIW I just used silicone caulk and no tape. I put a bead along the inside corner of the molding, and another along the line of screw holes on the roof. When tightened down any excess silicone squeezed out and was wiped off.

If you're getting a LOT of squeeze-out then you're using too much silicone. Best to try a small test piece first...