Guest User
8/3/2013
I had a huge screen room added on to my house two years ago with powder coated aluminum rails and insulated roof panels. Recently, I've noticed a white powdery residue that appears to be coming from the roof somewhere, since I only see it underneath and ouside, around the screen room. Looking online, I can't find a single thing on the particular installation method the installer used and am now worried about whether it was done correctly. I have found several things on installing metal panels on top of existing shingles, but in my case, the installer put shingles on the screen room to match the rest of my roof. Unfortunately, I don't know the details of how it was done since I assumed this was a common practice and didn't monitor the installation. I hope that you will tell me that there is a way to install shingles over a metal roof without damaging the integrity?? Thanks in advance.
Todd Miller
Isaiah Industries, Inc.
8/3/2013
Thanks. This is a bit outside my expertise but can you send me pictures of the screen room, including what was done with the roof, as well as of the white powdery residue? My email is [email protected]
Eric Novotny
An informed customer is the Best Customer!
8/4/2013
+1 Pictures are going to be very helpful in this case.
Guest User
8/10/2013
Sorry, we've had a lot of rain so just getting some photos together for you. The residue doesn't really show up in any photos well. It appears to be like foam or rubber shavings in small inconsistently sized granules. Honestly, I don't even know that it's coming from the roof or the panels. My main question now is whether it's ok to have shingles on these types of roof panels. I haven't seen anyone else mention doing this on the Internet.
Guest User
8/10/2013
Screenroom attached to house
Guest User
8/10/2013
Screenroom underside
Todd Miller
Isaiah Industries, Inc.
8/10/2013
It is I think uncommon to install shingles over metal skinned insulated panels. I would expect it will lessen the life of the shingles. It does look like your panels have the 3:12 pitch required by asphalt shingles. Is what you're seeing related to the EPS "styrofoam" inside of the panels? Is it possible it had gathered someplace from the initial installation and you're just now seeing it?
Guest User
8/10/2013
The residue does seem to float in the wind similar to styrofoam. I suppose it is possible that it was trapped somewhere but the screen room was installed at the end of 2009. I don't recall having seen it in previous years but it was pretty noticeable just in the last couple of months. As long as the installation method is only taking a few years off the shingles and not breaking down the roof panels somehow, at least for myself, it's acceptable trade off to match the existing roof I think. I appreciate your taking time to review my questions!
Todd Miller
Isaiah Industries, Inc.
8/10/2013
What was done has voided the warranty on the roof panels, I am sure. But, I am not sure that's an all bad thing. I agree the end result looks nice. I would sure keep an eye open for the source of the white stuff, if you can ever find it. All Best.
Patrick Clark
8/13/2013
I’m going to bet you have a kit or components from one of the patio cover manufacturers that uses insulated sandwich panels. The sandwich panels they provide are offered in several different assemblies including a half snap osb nailer with aluminum liner for shingle over applications like yours. As long as you have the OSB nailer insulated panel your installation looks fine. If the installer had used an aluminum sandwich panel, I can’t believe the shingles would have stayed as long as they have. All of the patio manufacturers I coat coil for use straight polyester paints for their panels and trim. The extruded parts are powder coated but the rollformed parts are straight poly. The straight poly paint will chalk after it has been exposed to the elements for a few years so you could be seeing some chalking. Please note I didn’t say all the manufacturers use straight poly paint, just the ones I coat for. Even though the panels are insulated they will still have some thermal movement, usually bowing outward as they go through the heating/cooling cycle each day. You are probably also seeing some differential movement from the different substrates on the top and bottom of the panel. This could cause some paint to get worn off at the panel joints or insulation dust to find its way out. This is normal as long as the panels aren't bowing or twisting so much that they are unzipping at the joints.
Eric Novotny
An informed customer is the Best Customer!
8/13/2013
A ring shank nail would grab the aluminum skinned panel as well, but like you said, not for long. The OSB/aluminum skinned SIP you mention is common for Sunroom manufactures and would be fine in this application like Patrick said.
Guest User
10/8/2013
Had missed the additional posts until now. I appreciate all the feedback and am feeling better about the small amount of residue and the install. Thanks guys!
Eric Novotny
An informed customer is the Best Customer!
10/9/2013
Sounds great. Glad we could help out and thanks for following up. Eric
Guest User
3/16/2015
Hi all of you roofing people! I am installing a metal faced SIPs roof at a 45 degree pitch and would like to know what my options are for a roofing material? I have been reading a lot of posts where people are saying you should not just shingle over the metal in addition to my contractor suggesting a peel and stick product. Please help me out here, I want to do the job correctly from the start.
Todd Miller
Isaiah Industries, Inc.
3/16/2015
Jessica, before I answer ... let me ask a question. I just wanted to confirm ... by "metal faced," you're referring to a reflective radiant barrier laminated to the outside of the SIP? Is that correct?
Guest User
3/16/2015
Hi Todd, the SIPs skin is metal not osb.
Todd Miller
Isaiah Industries, Inc.
3/16/2015
Jessica, how thick of metal? Is this just like a foil or something heavier?
Guest User
3/16/2015
26 Gauge AZ-50 Galvalume® Metal Skin
Todd Miller
Isaiah Industries, Inc.
3/16/2015
Jessica, can you email me please a link to the panel you're installing? What type of building is this? My email is [email protected] Part of me is wondering why you want a separate metal panel on top of that? Are you using a wall panel?
Guest User
3/16/2015
I would like to be able to do a shingle roof to match my house. I have read that you can not just install shingle over the metal due to heat issues?

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.

Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.