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GuyContinental
Understanding modern metal roofing

Hi all,

I'm having a tough time getting service providers to help me understand the differences between types of modern metal roofing- I've been quoted for two types, type 1 is a 29G "G-rib" and type 2 a 26G "Standing Seam". Standing seam is fully 150% the cost of G-rib.

From what I can tell standing seam used to be the clear winner in terms of seal quality because the fasteners were literally seamed into the panels and protected from the elements using a heavy and expensive machine. However, new systems *may* omit that machine by using a snap-lock system under what is essentially a pre-formed "seam".

Given that modern fastener techniques (self tapping hw and sealants) are pretty robust, is there really a rationale for the extra 50% in cost? Is there an in-between product that I should be considering?

FWIW application is a steeply pitched roof on a mountain cabin in western WV that can expect 180" or more snow/season. It currently has a tired and leaky cedar shake roof and the only permitted materials by the community are real/artificial shake or metal. Its slightly more to use cedar than standing seam and another step up to use artificial "Eco-star" cedar.

Any advice is greatly appreciated!

Best,

Guy

dj1
Re: Understanding modern metal roofing

Check the neighborhood and go with the most popular roof (that is currently approved). Also get some local roofers to bid on this job. You need a very good roof, 180" of snow sounds like a lot of snow to me.

dj1
Re: Understanding modern metal roofing

I forgot to add, don't be the first to try new roofing material, go with what works best in the area.

GuyContinental
Re: Understanding modern metal roofing
dj1 wrote:

Check the neighborhood and go with the most popular roof (that is currently approved). Also get some local roofers to bid on this job. You need a very good roof, 180" of snow sounds like a lot of snow to me.

The problem is that it's a vacation community and neighbors actually don't know what type of metal was used. As a result I don't think that they are a fantastic surrogate. Also the two local contractors with the equipment and skills are not exceptionally knowledgeable on product characteristics (I've had quotes from both) so I'm having to self-educate and may have to go as far as to identify a product and supplier. The closest "real" town is an hour away and I have yet to find a contractor that will travel that far (sort of surprised at that, the rural WV building industry isn't exactly booming...)

JLMCDANIEL
Re: Understanding modern metal roofing

With a highl pitched roof either type of metal roofing will work. By sure to have snow stops installed in critical places like over doorways. Standing seam are far better in stopping leaks if there is ice dams. A cool roof installation would be my choice.

Jack

guy48065
Re: Understanding modern metal roofing

Standing seam that needs to be mechanically crimped seems to be losing ground to the newer interlocking panels--but it's still the number 1 choice on commercial buildings so in my opinion that means it's still better and lasts longer.

Sometimes installation trumps material choice. Do both local guys use all the special trim bits that cover all exposed edges of the panels? I see a lot of jobs where the panels are just left overhanging the drip edge.

Sombreuil_mongrel
Re: Understanding modern metal roofing

The thing is, if you have a lot of unusual details, like dormers, built-in gutters, changes in roof pitch, valleys, flat areas, whatever, site-crimped paintable standing seam can accommodate any kind of odd detailing, because you can solder, flatlock, do tapered panels, with ease. The scope of details with pre-painted is less, and with snap-lock even more constrained.
For a very simple roof snap lock is a good alternative because it is cheapest. Prepainted standing seam then occupies a middle ground where detailing that is amenable to simply being caulked is deemed a workable solution, leaving terne to the hardest situations requiring the most hand-work and creativity.
Casey

keith3267
Re: Understanding modern metal roofing

First, the difference between 26G and 29g is the thickness of the metal. The 26G (gage) is about twice as thick as the 29G. For a residential home, yo need the standing seam rood, you can use teh cheaper stuff for barns and out buildings.

nauko
Re: Understanding modern metal roofing

Make sure they put a proper snow and ice guard underlayment under your roof. That is really important with metal roofs in areas with lots of snow to prevent ice dams. Also, keep in mind that your plumbing stacks should be near the top of your roof or the snow sliding off your roof could just slice the plumbing vents right off. I am in Seattle and have a Snap lock roof and when we rarely get snow, but it is crazy with we do. The snow slowly slides off the roof and hangs down in 5 feet legnths pratically blocking the windows and then drops making a huge sound. It could seriously injure someone if they were standing below that. We don't have the snow blocks as this happens once every couple years. I should also add. We have had a lot of problems with our roof with a leak we can't locate, but that is more about our roofer then the actual roof, but if you get a leak it can be really hard to track down the source.

guy48065
Re: Understanding modern metal roofing
nauko wrote:

Make sure they put a proper snow and ice guard underlayment under your roof...

It should be emphasized that the ice guard be installed over the entire roof--not just the edges. Condensation builds up under metal roofing & you need to protect your roof decking from that moisture.

Have you looked at the dimensional metal roofing? They're individual aluminum "shingles" and look really nice from street level. The high end stuff even has aggregate bonded to it with very long warranties. If something damages your roof you can replace 1 or 2 pieces rather than an entire panel.

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