It's hard to say without being there to see it. I would be surprised if there wasn't weather shield under the valley it's been code here a long time already. I've seen some house designs that you can see there could be problems with heavy snows. If it's not to steep and walkable get as much snow as you can off , your better off if you just skim the shovel over the shingles so you don't damage the granules.

Have you been in the attic to make sure that's where it's leaking? Water doesn't always come out directly below where it comes in sometimes it can be quite a ways away , it leaks down into the vapor barrier above the ceiling and comes out where there is a splice in the plastic or around ceiling lights. If there are any roof louvers they are notorious for having snow blow into them too.

It very well could be the valley and it's melted and backed up underneath. Usually newer homes aren't as bad for ice dams as older homes as a general rule.

I'd help but I'm from MN

If there is an ice dam it could have backed up beyond the Ice and Water Shield underlayment. Its 36" wide and it could have been installed lengthwise.....so 18" on either side of the valley center. That may not be enough but it would depend on the roof pitch and ice conditions.

It's code on lower part, valleys too?

That.

Yup. What do we know?

Osky

Without a pic it sounds like you have several valleys that meet. Sounds like the framer should have built a "cricket" which would help the water flow away before backing up under the W&I barrier. They are seldom shown on the print, but need to be installed regardless.

And that's why you NEVER put on a roof with out felt. (tar paper)

Felt won't stop leaks from ice-damming.

Thanks again for the help. I actually can't remember what his roof looks like myself. He just told me it is leaking from where all three roofs meet. Some of that roof on the north side never sees sun in the winter. He did call me today and said it didn't leak today. This summer we will have to take care of it.

A lot of asphalt roof leaks are the result of improper attic ventilation. Warm air, trapped in ridges, under where valleys meet, is a major enemy of shingles. Heat loss into an attic should be kept as low as possible. Ventilation helps to overcome this problem, by eliminating melting at the roofing under layment membranes. Ice melt should occur on the exterior surface, not at the underside of ice buildup. The perfect, but almost impossibly achievable attic temp. , is the same as the ambient temperature!

The only thing felt paper does is to prevent the shingles from adhering to the roof sheathing. Weather guard or similar product is the way to go. If your contractor is relying on roofing felt to prevent leaks then I suggest you get a different contractor.

Ice and water shields do a very good job of doing what they are supposed to. The main drawback to them appears later for whoever is doing the reroofing . Depending on the product used tear off can be a nightmare as the top half of the shingle that is in contact with the weather shield often adhears to it and won't come off. Same thing with the weather shield once it's applied it's not coming back off.

hrdtoflw nailed the main problem with most ice dams. It's usually a combination of not enough ventilation or not enough insulation or a combination of the two.

Water/ice that gets up under the shingles is sloughed off by the felt, and it's your last ditch protection from losing a few shingles in a storm.

Expensive, but worth every penny. Every edge and valley. That’s code now here.

That is absolutely untrue. The only thing felt paper does is act a temporary barrier. Felt paper is so riddled with holes by the end of a roofing job that it might as well be a sieve.
(Well, maybe I shouldn't be so harsh in saying it does nothing. It can certainly help.)

There are so many misconceptions in roofing that it will make your head spin. There is a local company near me that advertising their roofing expertise, but they are nothing but a total joke......yet they do more roofs by a long shot than anyone else.
I've been on a large project for years where they put on a new shingled roof about 7 years ago. It has leaked in multiple places from the beginning and every time we find a fix a leak you just have to shake your head.

It is very common for people to turn a shingle upside down around here for a starter shingle. I've seen it time and time again. That technique is totally worthless for its intended purpose.

I've seen step flashing against the structure that wasn't bent up the wall at all. Every piece was just a flat piece of metal laid on top the shingle and nailed. Again, totally worthless.

I've seen roof vent material installed without ever cutting a vent in the plywood.

My buddy's roof just lost a bunch of shingles today in the wind we're having. It was installed last summer by a local contractor. The nails were shot 6" above the nail line and overdriven.

I had a guy help me on a roof who had done "a bunch of roofs" in the past. He was in his 50s I'd guess. We put coil stock in the valley and then ice/water over that. Ice/water is a great material when laid flat, but if you crease it, it can tear very easily. The valley material was installed and he was putting the NOVA seal underlayment across the roof and into the valley. He was about half way up the valley when I noticed he was nailing within 2" of the center of the valley. Total nonsense.
We had some words. He said he always did it like that and couldn't see things my way. I paid him for the day and told him not to come back.

Bottom line is you have no idea what the problem is going to be until you get into it. Lots of roofers don't know what they are doing, but it's something that every entry level construction worker thinks he can do.

How would a shingle adhere to the sheathing?

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How would a shingle adhere to the sheathing? [/quote]

Underlayment (felt/tar paper) acts as an insulator of sorts and helps the asphalt that leaches out of the shingle stay in the shingle and not leach into the wood decking. Shingles get really, really hot from the sun. I've had white marks on the hands more then once from leaving tools sitting on the shingles for an extended time. So many people think they can do roofing. So many people are wrong. What kind of warranty did the contractor give on the new roof??? Taillight warranty?? Most do, If they wont cover it for at least 1/2 the expected life of the shingle then give them the taillight salute.

Looks good from the ground....

27 years ago my business covered these steeples with triple lock standing seam lead coated copper...it was stone and the acid rain was deteriorating the mortar/stone so it had to be pointed periodically and chunks of stone were falling off once in a while..... I told them a lead coated copper roof would last forever and they would be done with it if they had me do it. As far as I know every piece of copper we put on has stayed in place....