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Roofing/Aluminum Patio Cover Sealer


QUESTION: Hello John,
I had an aluminum patio cover installed a few years ago and the sealer that was used around the screws and along the joints on top of the cover (Vulkem 116 I think but not certain) is beginning to deteriorate from the constant sun (I'm in southern CA).  I'd like your recommendation on the best product to use to reseal the joints between the panels.
Thank you!

ANSWER: Baron,

Thank you for posting this question and I will do my very best to answer it in detail.

Aluminum patio covers are an ideal product for long term use but one drawback can be the longevity of the silicone or rubber seals used when installing the material.

In my personal opinion to reseal the joints there is a product by the brand name of NPC Solar Seal that works great on all types of metal whether it is painted or unpainted.  Just make sure the joints are clean and free of any debris.

As for the screws the seal around the fasteners are typically a rubber washer that comes with the fastener.  To replace those seals it would be best to replace the fastener itself.  There are many good companies that make fasteners with rubber seals. The main thing to look for when shopping for replacement washer fasteners is that the washer be made of an EPDM Rubber and not a Neoprene material.  Neoprene material is a great material when used for fuel gasket material but does not have the UV resistance that EPDM rubber has.
If it is decided to replace the fasteners determine the size and type of fastener so you get one that will work for your application.

The caulk sealant can be purchased from many distributors. Or you can visit my website to learn more about it.

Thanks and have a great day!

---------- FOLLOW-UP ----------


Thanks again for your prompt and well-considered response!

I'd like to ask a couple of questions about NPC Solar Seal now, if I may...

 1.  Is NPC Solar Seal considered a "Tripolymer"?  
I looked at their website which describes it as "built on...Terpolymer Technology"

 2.  How does it compare to Titebond Metal Roof Sealant?
I was searching the Internet for comparative information and found a sales brochure (PDF) that claims to be a better product than tripolymers (you can find the document by searching for "FF801_WM_MetalRoof_SalesSheet.sflb" if you'd like to see it for yourself).

Kind regards, Baron


Good evening!  

NPC Solar seal is a terpolymer which is an alternative word for a tripolymer.

I have never personally used the tightbond product so I could not give an opinion on how it works.
The PDF File was informative for the tightbond product.  Thank you for linking the source. I may order a tube but would not give an opinion until I am able to test it myself.

Tripolymer and butyl based sealants work much better for metal roof or siding applications since they are more uv resistant.  Some silicone sealant have a uv additive but tend to not hold up as well as the butyl rubber or tripolymer sealants.  The tight bond claims to be watersoluble but in the fine print the translucent or clear is not watersoluble.

Interesting for sure whichever way you decide to go please let me know how it works for you in your application.



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John Nutter


Residential and commercial metal roofing such as exposed fastener systems and standing seam systems. I can assist with facts about metal roofing and the manufacturer specified applications of metal roofing. General troubleshooting issues with metal roofing and helpful hints on how to make the job easier.


Currently I am the manufacturer specification trainer for Triad Corrugated Metal Inc.

Valspar PQI trained. Triad Corrugated Metal Inc specification trained.

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