Flat roof roofing material is too short

[Hakeem]

I noticed some peeling paint under my patio roof, did some poking around and found that the “soffit” was rotten (the outer two 2x6:


Replacing the soffit boards is easy enough, but how do I keep this from recurring? As best as I can tell this happened because the existing roll roofing was too short so water was able to get up underneath it and keep the wood moist.



My instinct would be to slide roll roofing underneath the existing layer, leaving 2-3” overhang to be nailed to the fascia. The seam between the new roofing and the existing roofing would be sealed with roofing cement. Maybe I’d cut the old roofing back 6” or so, just so the seam isn’t right at the edge of the roof.

Am I on the right track? Any better ideas would be appreciated

 

[PCustoms]

That plywood looks rotted too....

My guess is by the time you get to good wood, it would be easier to replace it all. There should be metal drip edge, then the first "row" of roofing, then the next row overlapping on top of that.

 

[BillK]

Something like this should work. Not sure what to tell you about the rotten wood.

Amerimax Home Products F4.5 x 10 ft. White Aluminum Drip Edge Flashing 5505400120 - The Home Depot

Amerimax Home Products Aluminum Drip Edge is suitable for both new construction and reroofing. Offers long term durability.

www.homedepot.com

 

[Wolley]

It looks to me it's leaking higher up and running down the plywood. Then damming up on the existing metal trim under the rolled roofing. I'd check for leaks and tar the edges if you want so try and get more life out of it.

 

[Hakeem]

Something like this should work. Not sure what to tell you about the rotten wood.

Amerimax Home Products F4.5 x 10 ft. White Aluminum Drip Edge Flashing 5505400120 - The Home Depot

Amerimax Home Products Aluminum Drip Edge is suitable for both new construction and reroofing. Offers long term durability.

www.homedepot.com

Thank you all for the suggestions, yes I believe this should do the trick. Once I disassemble it I’ll be able to evaluate the extent of the rot and replace components as needed. The “structural” 2x6 from which the roof is supported seems solid so if all goes to plan I can simply unfasten, remove, and replace the outermost 2x6s. I expect 1-2 sheets will need to be replaced but that will be determined once the roofing is peeled

It looks to me it's leaking higher up and running down the plywood. Then damming up on the existing metal trim under the rolled roofing. I'd check for leaks and tar the edges if you want so try and get more life out of it.

As best as I could tell, i think it’s just the edge. I’ll poke around at the part where the addition comes together with the garage just to be safe. The previous owner did all kinds of unorthodox stuff so who knows what horrors are lurking for me to find.

 

[Bert_]

Something like this should work. Not sure what to tell you about the rotten wood.

Amerimax Home Products F4.5 x 10 ft. White Aluminum Drip Edge Flashing 5505400120 - The Home Depot

Amerimax Home Products Aluminum Drip Edge is suitable for both new construction and reroofing. Offers long term durability.

www.homedepot.com

That style of drip edge does NOT work well on a roof with marginal slope.

My porch roof has about a 3:12 pitch, maybe a hair less. That type of drip edge had been installed and it let water run back against the facia and some places water would wick underneath if the drip edge was pulled to tight when they nailed it.

I made my own drip edge that has a 6" leg that is covered by the shingles and it extends a couple inches out from the facia. Works extremely well.

 

[CraigStu]

Along the lines of Bert's comment you could get a seemless gutter guy bend up an edge w/ longer legs.

 

[acer66]

I would use a gutter apron which is basically a drip edge that extends into the gutter.

 

[jar944]

How flat is that roof?

 

[alwaysFlOoReD]

Ice and water shield. Aka peel and stick. Use it for at least the first 3' of the roof under the new roofing.
You'll notice on the gutter shield pic the roofing sticks past by an inch or more... That's the correct way

 

[CraigStu]

Acer that stuff is fantastic. I learned something today. Thanks.

 

[acer66]

Another way to deal with is to put flat pieces or I would get a coil of aluminum run it under the drip edge and into the gutter.

Which they did here.
A bit patchy though but it defiantly works.

 

[Hakeem]

Ok, I had to wait for good weather but managed to disassemble the roof one evening after work. The seams between the sheathing had failed and was letting water in:



I got my 78 year old dad to come help me and we knocked it out in two days. We had to replace one of the structural 2x6 so we built a temporary 2x4 wall to hold the roof while we removed & replaced everything. We replaced a few sections of rotted plywood but less than I anticipated. After the first day here’s what it looked like:



We did 2 through bolts at each section, it’s just not pictured here. Followed up with drip edge + flashing, then underlayment, then roll roofing. Plenty of roofing cement used at all the seams. We used a drip edge and tucked the gutter into it, and then used strips of flashing for the areas where there was a gap between the gutter and the drip edge.


Here’s the final product as seen from under the roof, note the new lumber:


So yeah, got it done for about $200 and I can enjoy the satisfaction of having repaired it myself. Best of all, I got to do it with my dad. I like to think I’m in good shape and can work hard but I could barely keep up with him. What a tough SOB. 78 years old and he was climbing up and down ladders & getting up on the roof like it was nothing. I would have taken more progress photos but he had little patience for that

Anyways, thank you to all for the suggestions & comments.