Roofing cement vs silicone

I have a 15 year old asphalt roof. Upon recent inspection, it seems there are many nails left exposed on the ridge cap. None of them are leaking at this time, but of course I want to cover up those nail heads. I’ve looked online and I hear a lot of back and forth on which is better. Silicone or roofing cement. I’ve heard silicone is more flexible, but I’ve also heard it will shrink/pull away eventually from asphalt. Then again, I hear that roofing cement will eventually crack. Any opinions are appreciated. Which is best, lasts longer, etc. Thanks, guys!

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Dont use silicone on shingles, roof cement or other roofing caulk will be fine.


Urethane based (PL brand at your big box) or tri-polymer (geocel) are both more effective than sillycone or old school roof cement.

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use anything you have ,its just ridge caps.

I don’t use silicone on anything permanent


Silicone should not be used on a roof.

Cement cracks because it shrinks as it dries or from excessive movement of the substrate. A dab of cement thick enough you can no longer tell where the edge of the nail head is enough to last quite a while.

Urethane and geocel are also good and you can get them in multiple colors, but if your shingles are excessively dirty, dusty, or degranulating all of these will come off.

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Thanks for all of the opinions! It really helped me out.

Silicone being a polymer, continues to cure, and ultimately divorces from the surface as it shrinks.

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loctite polyurethane roof sealant home depot carries it todays roof cements ,most of them are crap

Loctite Polyurethane is crap too.
It hardens up, cracks up and fails quick.
Not to be recommended.

Geocel or Volkem are good, but need to be protected from sun. I started cutting small 1"x1" squares of shingle, then I put a dab of geocel on the nail head and stick the square on to protect it.


Ask the manufacturer:)

That is a crazy, anal detail and I respect the heck out of you for thinking of it!

Handful of gutter gravel does the same thing.


just looked at sealant i put on over 8 years ago still good you must have used an out dated batch

Glad this subject got brought back up.

I use the best polyurethane i can buy.
Geocel isnt and it shrinks.
I stopped using it after i saw how it reacted trying to stop a leak on a T1-11 sided chimney.
Vulkum i really believed in for almost 20 years.
But i remember when they changed their formula and i didnt like it.
It still works but i just just dont think it is as good as it once was.
Also very resistant to adhering to any moisture, dirt, dust what so ever
And in this world, the conditions are not always perfect.
It is still my 3rd go to polyurethane
My #2 is NP1
My #1 at this time Mulehide joint and termination sealant. JTS1 for short.
I just whipped out a tube from my tool box
And it says in bold letters on the side
“Adheres to wet and underwater surfaces”
I didnt know that,
But i have experienced its top performance over and over and have real confidence than i have solved their issue when ever i use it.

I am sure my position will change
Because formulas and suppliers change…

Now all that said,
You should not be using ANY of this stuff
To adhere to shingles. Period.
Even if the sun never touches it
It still divorces from the shingle.

Use a flashing cement
A neoprene cement
A high grade cement and cover it with granules.
After i toss the granules on it
I do gently push it in with my hand
to imbed them.


I’ve been using Lucas #9600 urethane for a while now, I like it.

I like all the Lucas products as they all seem to perform very well for what they are designed for.

The transmission additive is nothing short of amazing, it pretty much repaired a mis-shifting transmission for 2 months until I could get a new one.

Free plug for Lucas I guess.

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I use a lot of Lucas products also.

silicone is good for implants tho

np1 will stick to elon musk, and hes as slippery and slimey as they come