Where the house/garage roofs converge

When the garage was added on, the fascia boards were evidently contacting the shingles on the garage, causing extensive rot.

I assume that there should be a gap between the fascia and the garage roof to prevent wicking of moisture. If so, do I extend the aluminum fascia cladding to the roof to keep critters out? (but I don’t like the idea that moisture can still get behind there).

What about some sort of step flashing inserted between the shingles and behind the aluminum fascia trim?

The new board isn’t yet attached; I propped it up to illustrate.

There must be a better way. Ideas?



Yeah you are best with a minimum 1" off the shingles with the fascia board, then step flashing between the shingles/fascia board, then finish it all off with aluminum fascia to cover the wood and step flashing ( I usually keep it about 1/8 off the roof to allow for expansion due to temperature changes.

Are you replacing the shingles at this time as well?

Perfect- thanks!

Yes, I am replacing the shingles. The house will be complete now after this slope but I may have to postpone the garage until spring as I fear I may run out of good weather.

Q: Do I need to apply shingles to that portion of the garage roof deck that lies behind the area in question? Access up in there is kind of limited.

Q: What about where the soffit meets the garage roof… the builder evidently could not get the panels all the way up, leaving an entry gap for small animals (again, difficult to access).



I get called out to repair leaks in the exact same situation all the time. It’s one of the most common problems out there. Inexperienced roofers just cut around the facia sometimes applying caulk and sometimes they don’t even do that much.

The way I fix it is by taking up the shingles ( the top 4 in your case from where the facia first meets the garage roof up to the bottom of the valley ) and then installing a single piece of roof to wall flashing. ( 20 inches long on yours ) The flashing goes behind the facia not on the outside.

Also, the valley metal on the main house side should extend over the facia. Sometimes they cut it short. Raise the bottom couple shingles up and check it. If it’s short slide a small piece underneath to extend it and cut it off even with the shingle overhang.

If the soffit is cut properly there should not be any openings for critters to get in.

Check out this thread. how-would-you-felt-and-shingle-this-type-of-valley-t15371.html

That is the best way I know to explain it. As far as the fascia goes, as someone already said, if it is wood wrapped with aluminum, keep the wood an inch or so off the shingles, and then let the aluminum go tight to the roof. If you are not wrapping with aluminum it might be good to use PVC or something else that won’t rot. I would advise against leaving a gap there. You will have all kinds of critters in your soffit. Bees, squirrels bats etc…


I may have to replace the sheathing along the eaves so if I use your idea everything would be in the open and easy to access from above. Thanks!


Thanks for the link you provided, it was quite helpful.

Would there be any harm in my situation in leaving the new valley flashings a little long so that the water spills out farther away from this intersection?


Not a problem with leaving the new valley metal a bit long to keep water out of that area. That’s how I would do it and I suspect most here would agree.


Would there be any harm in my situation in leaving the new valley flashings a little long so that the water spills out farther away from this intersection?


Not at all, in fact this is a very good thing to do if you like the way it looks.

Guys, thanks for the great and abundant advice! I very much appreciate it.