# Tying a metal roof into a shingle roof



## Nealtw (Jun 22, 2017)

ponch37300 said:


> We have a shingle roof at about a 6/12 pitch over our garage. Want to add a covered porch behind it. Covered porch will be about a 4/12 pitch. So will be framing it up with 2x6s and then 1x3s on top to screw the metal panels to. Question is how to tie the new metal roof into the shingle roof? Obviously I will have to try and lift up some of the shingles and then I'm guessing use some flashing tucked up under the existing shingles and then on top of the new metal panels? Or is there a better way?


How are you tying the structure to the building?


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## ponch37300 (Nov 27, 2007)

Nealtw said:


> How are you tying the structure to the building?


Going to run 2x6s as rafters and will land on the garage trusses. This porch roof won't be big or have much weight on it. My main concern is how to tie the new metal roof into the existing garage shingle roof and how to flash that.


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## Nealtw (Jun 22, 2017)

ponch37300 said:


> Going to run 2x6s as rafters and will land on the garage trusses. This porch roof won't be big or have much weight on it. My main concern is how to tie the new metal roof into the existing garage shingle roof and how to flash that.


 I would want about 10" of flashing on the 6/12 with half of it under the upper shingles. And seal the bottom of the flashing to the metal roof so the wind can't blow water up there. 

Roofers will be along.


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## Nealtw (Jun 22, 2017)

Have you seen this.


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## roofermann (Nov 18, 2013)

Great example, Nealtw. Ideally the shingle roof potion of the transition flashing should extend past where the bottom row of shingles is nailed.


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## huesmann (Aug 18, 2011)

Presumably the OP will be adding a new downspout?


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## BigJim (Sep 2, 2008)

Nealtw said:


> Have you seen this.


I did mine just like that and it leaks, not in the house but runs down onto the asphalt shingles under the metal roofing. I would suggest making the bends in the flashing and at the transition point closer. I had to install an additional flashing under that flashing to make it stop leaking and it still leaks with a really hard rain. 

It doesn't hurt anything as it just slightly drips on the treated, sealed floor of the porch. Make sure the rubber gromet that goes under the metal flashing onto the metal roof is back away from the edge of the flashing. You want as much flashing over hanging the gromet as possible.


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## KylieHodges (Dec 8, 2020)

Yes, this is a great idea. This will definitely work. I did a similar improvement for my roof and I can say that the main problem is that you need to use a good sealant in order to avoid leaks. When the guys from Roof Calgary saw my work they immediately said to change the sealant as I said that I used a fairly cheap one. You can't try to save money on the roof because it's a very important part of the house, especially since I live in a very rainy place. In such complex repairs, it is better to ask for professional help.


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## HuckPie (Nov 15, 2020)

.


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