Metal roof

[SIKSUKR]

Add these on.

[jmen24]

SIKSUKR makes a good point. You can add snow guards to prevent the snow from falling off and in some cases or areas, it would remove the issue of snow falling off. I have a version of these over the roof penetrations to prevent damage to vents.

Two things to consider:

1. If the snow cannot fall off, you have to remove it from the roof to prevent a structural issue, same as you would with Architectural shingles. Metal roofing will melt the base layer of a snow pack, thus increasing its weight on sunny days (to a point, it will eventually get lighter as water falls off the roof). This is not prevented by increasing insulation. Metal absorbs and radiates sunlight very well. It only requires a small amount of metal to be exposed and it expands from there.

2. These can add an additional cost to the install. It may very well make it worth the additional cost if you are looking to protect a couple of specific areas. In order for a snow guard to be affective you need to prevent the snow from moving, this requires an install that matches the photo posted. If you only installed protection at the bottom or eave line, all the weight of that snow above rests on that one point and it could let go.

I would not consider covering my entire roof with these, as I think they are not overly attractive from a residential design standpoint. They do work though.

[HellRaZoR004]

Originally Posted by jmen24

Metal roofing will melt the base layer of a snow pack, thus increasing its weight on sunny days.

Um, I have a problem with this statement. Conservation on mass, i.e. water is water. You're not going to add weight by melting snow (into water). Add more water to the mix then you have this issue (especially if it rains) as snow tends to collect the additional water and not disperse it.

Remember, volume can change, but in a closed system (nothing added/removed), mass will never change.

Now movement of all the weight to the edge of the roof when it melts is likely and will need to be addressed just like any other roofing material.

[Long Pine]

Has anyone put a metal roof on a gambrel? Any concerns? I like the idea but I'm wondering how the seams would work where the roof changes pitch.

[jmen24]

You got me on that one!

Density for weight in the first sentence. The rest holds water!

[mneck1814]

I have a standing seam and love it! We do have the "bear claw" snow guards over the front door and the slider on the deck. As I understand it, there are different types of guards for different scenarios and each type has a specific pattern that they need to be installed in. Mine basically just hold the snow over the doors and it gradually melts, usually within a couple days of a large storm.

My roof was installed over the old shingles which caused a slightly longer overhang which made our 4" gutters useless as the water shot off right over the gutter. We have since installed 6" seamless aluminum gutters with caps that work really well with the standing seam roof.

At the lake we also have a metal roof and it has worked very well there and has relieved the urgency of getting over to shovel the roof after a large storm.

[Tackleman]

You guys gave me a lot to think about. I wanted a metal roof so that I would not have to worry about shoveling it off. I was thinking about the shingle style,of metal roof. If you use he snow stoppers will,it melt after a big storm or do you still,have to shovel,it off? I have a deck facing the water and I would not be up there right after every storm. If I used snow guards would I have to worry about ripping the deck off?

[mneck1814]

I never have to shovel my roof. The guards are just to control the snow dumping in front of the doors, the small area (maybe 10 feet of roof) melts pretty quickly after a storm and everything else slides off. I don't have the problem with snow getting stuck in the valleys, the snow slides from those, too. Where the snow comes off onto the deck I do have to shovel that relatively soon after it comes off the roof before it freezes solid, I have always shoveled the deck after a storm anyway.

[SIKSUKR]

Shoveling snow off your roof is one of the biggest mis-hypes by the media. Most homes in this part of the country have to be built for snow load. While not true in all cases, it pretty much depends on the pitch and the size of the framing. Very flat roofs should at least be cause for concern but the normal northeast pitched roofs are just fine. I prefer to have that snow on my roof as it is great free insulation. And as has been addressed prior in this thread, another big misinformation by the media is after big snowfall they love to tell you that the warm temps will be adding weight so get that snow off now. Rain, of course is a different story but for those with flatter roofs, be happy if warm weather follows because any melting will lighten the load.

[Happy Gourmand]

Originally Posted by SIKSUKR

Shoveling snow off your roof is one of the biggest mis-hypes by the media. Most homes in this part of the country have to be built for snow load. While not true in all cases, it pretty much depends on the pitch and the size of the framing. Very flat roofs should at least be cause for concern but the normal northeast pitched roofs are just fine. I prefer to have that snow on my roof as it is great free insulation. And as has been addressed prior in this thread, another big misinformation by the media is after big snowfall they love to tell you that the warm temps will be adding weight so get that snow off now. Rain, of course is a different story but for those with flatter roofs, be happy if warm weather follows because any melting will lighten the load.

I agree. For the most part, I think you are likely to cause damage to a roof by shoveling it. Not only by hitting it with the shovel or anything else, but by possible damaging the shingles by walking on them when they are cold and brittle.
Of course there are exceptions...flat or near flat roofs built before current standards could be cause for concern. Otherwise, like Siksukr said, take advantage of the extra insulating value of the snow cover.

[DickR]

While the durability of metal roofing is one thing, there are the issues of snow sliding off it to places you'd rather it not pile up. If you are building a new house and think that you ought to have a metal roof so you can avoid having to shovel snow off it, think again. As pointed out, the roof must be designed for a heavy snow load, so for a new house there isn't anything particularly wrong with letting the snow stay there.

If the intent is to avoid ice dam formation and excessive icicle formation, bear in mind that in nearly every instance the formation of ice dams and icicles is an indication of heat leaking into the space under the roof deck. For a new house, there is no reason why this ought to happen, if care is taken to avoid this sort of heat leakage. Take care to seal the upper level ceiling against air leakage into the attic space. Avoid can lights there; they are a bad idea, from a building science point of view. Provide adequate soffit and ridge ventilation. Keep the heat out of the attic and you avoid roof ice issues.

For a lot of good information on this sort of thing, a good site to browse is www.greenbuildingadvisor.com.