[billmee]

We have a 1950's cape in NH with some ice dam issues.
The ice dam builds on the side of our dormer and leaks thru the cheek wall.
I removed the cedar shingles to find the roofs flashing OVER the grace snow and ice attached to the cheek.
The flashing extends only 2.5" up the cheek.

My options now... ( please suggest your own as well )
1. Remove all the roofing material and flash correctly, then snow and ice over the flashing and up the cheek.
2. Snow and ice over the existing flashing and melt wire.

 

[Michael Thomas]

For starters:

1) Judging from the picture, at the slope of that dormer roof conventional shingles are not an effective water barrier, their function is decorative, and the actual water barrier is the underlayment, which at that pitch should be waterproof shingle underlayment (WSU) such as "Ice and Water Shield".

So the first step is to determine what's under the shingles, and provide a proper underlayment if required.

2) Again, as best I can judge from the picture, there is no drip edge and either the rakes or the eave, on a low sloped roof these are vital to prevent water from soaking into the sheathing and structure below.

3) The step flashing needs to be under the vapor retarder at the junction of the dormer wall of the roof below.

4) The new siding and the vertical and horizontal wood trim at the dormer should be held back at least 2" from the roof below.

5) You need a better flashing detail at the corner of the dormers, for example by extending the lowest piece of step flashing past the lower corner of the dormer so that water is channeled past the edge of the dormer.
　
　

 

[Scuba_Dave]

We have a 1950's cape in NH with some ice dam issues.
The ice dam builds on the side of our dormer and leaks thru the cheek wall.

Since the ice dam builds only (?? only on the side?) then you have multiple problems

#1 Heat is getting thru & melting the snow, causing the ice dam
Is this area (the small roof) insulated & vented
Many are insulated - but not vented
If possible take it apart inside & redo the insulation & add rafter vents along the roof deck

Is the wall correctly insulated?

#2 Due to the ice/melting water is building up higher then the flashing & leaking in
IF the leak is only due to the flashing then I would add ice & water shield at least 12" up on top of the flashing aginst the house
Then I would add additional counter flashing along that edge & (cedar) shingle
Keep the cedar shingles up off the roofing

If the water is not backing up thru the roofing shingles then there is no need to replace the roofing shingles

One reason I opted not to put the small roof area on each end of my dormer - too many possible problems...more flashing

Any winter pics of the problem?

MY 50's Cape only had R7 in the walls & 2nd floor ceiling

 

[MJW]

It probably has an ice dam because of the sun hitting only parts of the area. It melts the snow until it hits an area that is shaded. Then you have an ice dam.

There is roof edge up there, and make sure that dormer is vented properly.

Leave everything alone, just put some new 30 lb or house wrap on that wall. Make sure it goes over the flashing.

A heat tape may help also. You can check out the insulation, but I would guess other areas of the house are a bigger problem if you have a lack of insulation.

 

[billmee]

...To answer some questions.

There 'was' no insulation in the area below this roof- R30 now
Soffit vents are clear and proper vents installed
The water definately came in the cheek wall not the roof.
Heating system 3/4" pipe directly under has been insulated ( burried in pipe insulation and pink )

I think this is an old issue for this house that was fixed some time ago.
Unfortunately the last owner hired a low bidder for the last roof.