After buying the house, I discovered the problem while removing a bird’s nest.
Rain from the upper and lower roofs can seep along the lower roof shingles and under the upper fascia. It looks like various attempts at caulking were made. That slowed down the problem but never fixed it as the upper soffit drops below the drip edge of lower roof. Water on that edge will seep into the soffit grove of the upper fascia causing the damage you see.
To get the water away from the upper fascia I think I should put in step flashing. However, the concern is that step flashing should be installed under shingles and up the fascia to be effective. That means I’d have to cut! You can see from the pictures that the shingles run continuously under the upper roof so cutting could effectively create another weak point. Installing flashing on top of the shingles would mean that water could still seep between shingles. I am guessing that’s the whole reason why caulking was used in the first place. (Either that or cost or laziness)
The second problem is what to do with the upper soffit that comes below the lower roof drip line.
You can put your step flash under the shingles and BEHIND the facia. That way they are hidden from site and catch any water that may run down your facia.
As far as protecting your soffit, make a diverter as kage said, just to push the water away from the soffit area.
Be carefull with those abestos shingles they break easy and depending on your location may be hard to get,we have a bunch of those american traditionals or colonials.If you have to remove nails you will need a slate ripper or roofer samuri,i prefer the samuri as it just cuts the nails and you can reuse the shingles.The ripper will break the shingle if its not copper nails,that shingle will last over a 100 years with proper maintence.Biggest mistake made is letting shingle roofers up on them they do more damage then good.
IMO, the valley is improperly installed and there should be step flashings along the wall. You cannot easily life the asbestos shingles without risk of breakage.
I suggest that you carefully remove the caulk then slide step flashings under the edge of the shingles carefully starting with the bottom shingle so that the gap between the fascia and the roof line is covered. Nail them in place high on the fascia and trim the top ones to fit the angle. Make sure they overlap one another and the gap is completely covered.
When you re-roof, replace the fascia board with one that meets the roof within 1/4" and fill the space behind it with insulation before you replace the roof and soffit.
If you cannot install step flashing for whatever reason, use plastic cement (Karnak, Lexan, Bulldog, etc…) and 6" wide mesh fabric. Make sure the roof is dry, apply a layer of plastic cement about 1/4" thick four inches onto the roof and four inches up the fascia. Lay in the fabric in a strip longe enough to cover the entire gap between the fascia and the roof. Smooth it down with the trowel so that it is 3" up the fascia and 3" on the roof and the plastic cement has come through the mesh enough to cover it. Lay on another 1/4" of plastic cement and you’re done.
BTW, I just love the bronze caulking dam. That was clever, if ineffective.
Step flashing won’t stop this leak. Take a look at the valley end. Notice that there is about 6" to the right that water runs under?
AND, just above/to the side of that issue is the other biggie. There is a butt joint on the right side that nearly lines up with that piece of wall where the leak is and behind the little caulk dam.
On the right side, one more course of shingles should have been over the valey end. You need a bib at the joint, and ugly but functional, a bib to cover the end of the valley.
The wall needs flashing, but the leak is well above the symptom.
VERY good eye tinner. I think you are right, and I’m willing to bet a bib at that butt joint alone would solve the problem.
As a side note, I have run into this problem several times with large shingles, like Hatteras, Slateline or occasionally Grand manor. Sometimes when I have a dormer or A frame that intersects partway up the main roof I can’t find a good place to put my metal between courses of shingles. It happens most often with the Hatteras type shingle cause it has those huge keyways. They always seem to land in a spot that shows the top edge of the valley metal, and will allow water to run under the metal. In the past I have just cut a starter shingle to lay under the field shingles in that spot. Obviously with these asbestos a bib is the way to go.
First of all, I’d like to say many, many thanks to all that replied to this post. I learnt some extremely valuable information that I think will help me take steps to fixing this piece of work.
I posted a new picture which has been adjusted with photoshop here.
So, the first idea would be to fix the leak at the valley. I think I might be able to slip a sheet of aluminium under the shingle as shown to cover the edge of the valley end and to get under that butt joint. I’ve outlined the sheet in red. Thanks to tinner for that excellent eye.
As mentioned, the shingles are very hard but easy to break. With that in mind, I think WarGoddess’s suggestions fits best i.e. using plastic cement with mesh. There’s no way I could get flashing in there to ensure a water tight joint. (The bronze dam and caulking I magically erased in photoshop)
I’ll also make a diverter at the starter as Kage mentioned so the fascia doesn’t rot when I replace it.
The tiles I have are very similar if not same to Kubota’s Colonial Grande Glassa.
This page will come up in Japanese. Use google to translate or even easier use google chome to navigate, then right click in the page and select translate to switch the page to English.
Again, many thanks and appreciate and further advice
Bamber. Very interesting.Show when it will be done.I never did repair with asbest shingles befor,only tor off, and i have no idea wheare take extra mat., in case for replacement.
Very interesting.Show when it will be done.I never did repair with asbest shingles befor,only tor off, and i have no idea wheare take extra mat., in case for replacement.