Roofing questions, replacing old flashing where wood siding meets roof, etc.

Hi all. Our complex is in need of some new roofs. Most, if not all, of th e old flashing was nailed to the sides of the buildings, and not to the roo f decks. My understanding is there is a way to cut off the bottom 6 inches of existing wood siding (to avoid having to remove all siding) and then, a fter the roofing work is done (which includes both ice and water shield as well as new flashing) they would replace the bottom 6 inches of siding with a trim board that is removable because it is attached with screws. I have a few questions.
1) what is the proper method of attaching the trim board to the bottom of t he side of building? What exactly is the trim board screwed to, and what p revents water from getting behind the gap where the trim board meets the wo od siding above it? I'd like to know the correct terminology so it can be mentioned when requesting bids.
2) Can the method of cutting off the bottom 6 inches of wood siding and re placing with a trim board (I'll refer to this from now on as trim board met hod) be used in all areas where roof meets siding? (e.g. areas that involve step flashing where side of roof deck meets side of building. and also are as like fronts and backs of buildings that involve continuous flashing at t ops of roofs that meet siding )??
3) Can that trim board method be used around the bottoms and sides of chimn eys that have wood siding as well
4) If the side of a roof meets side of building (step-flashing is involved) and there is horizontal siding involved, is it really possible to cut off bottom 6 inches and replace with trim board or does the siding have to be r emoved and replaced. (I'm asking this because it would seem awkward to try and cut off the bottom of horizontal wood siding at an angle, as opposed t o the bottom of vertical wood siding in this situations)
5) Will the "trim board method" look lousy in the fronts of buildings, or l ook acceptable?
6) How many inches of ice and water shield should we require be installed f rom bottom of roof near gutter upward. Should we require 3 feet, or 6 feet ?
7) We plan on requiring 6 inches of ice and water where siding meets roof. Should we require this only for sides where step flashing is involved, or also require this at tops of roofs that meet fronts/backs of buildings, wh ere continuous flashing is involved?
8) We plan on requiring a drip edge where roof meets gutter. I assume a dr ip edge is nailed to the fascia above gutter, and tucked underneath bottom shingles. If that's the case, is it important that the nail heads be seale d with caulk, and should they also caulk the top of the drip edge where it meets the tar paper underneath the shingles so that, in an ice-damming situ ation, the water won't get underneath the top of the drip edge, and then th e water could freeze, and force it to come loose, etc?
9) what is required at sides of roof on gable ends to prevent rake boards f rom rotting or water getting behind siding, etc? Ice and water shield? An ything other special flashing? What is the correct terminology?
Thanks.
J
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On Friday, May 18, 2018 at 1:10:59 PM UTC-4, jay wrote:

the old flashing was nailed to the sides of the buildings, and not to the r oof decks. My understanding is there is a way to cut off the bottom 6 inch es of existing wood siding (to avoid having to remove all siding) and then, after the roofing work is done (which includes both ice and water shield a s well as new flashing) they would replace the bottom 6 inches of siding wi th a trim board that is removable because it is attached with screws. I ha ve a few questions.

the side of building? What exactly is the trim board screwed to, and what prevents water from getting behind the gap where the trim board meets the wood siding above it? I'd like to know the correct terminology so it can b e mentioned when requesting bids.
Fastening it is easy. It should be nailed through the sheathing into the framing. Where the framing is located can be figured out by looking at the existing nails in the sheathing. How you handle the joint between the existing siding and the new trim board, IDK, but you're right, it's a problem. Which is why I would not do it. I recently had my roof replaced. I have vertical cedar siding and we handled it by simply pulling out the old step flashing and slipping a new one in. If it was done correctly to begin with, you should be able to do that. I had one area where they broug ht the siding down too close to the roof. That was already a problem, it was wicking up water and starting to rot the ends of the siding. In that section, we wound up removing the siding, trimming it to the correct length , re-installing, then doing the roof. Fortunately that wasn't too bad because it was a wall only 4 ft high, where a higher part of the house meets a lower roof.
If you have a trim piece running along the bottom of the siding, keeping water out of that, I only see two ways. Caulking it, which is questionable at best and won't last or putting flashing in the gap, which is going to look weird. The trouble comes when they didn't do it right to begin with, eg nailing the step flashing to the vertical side wall.

replacing with a trim board (I'll refer to this from now on as trim board m ethod) be used in all areas where roof meets siding? (e.g. areas that invol ve step flashing where side of roof deck meets side of building. and also a reas like fronts and backs of buildings that involve continuous flashing at tops of roofs that meet siding )??
Per above, I think that's a bad method. Does the siding end about 1" above the roof deck? If so, how about slipping new step flashing in front of the existing step flashing?

mneys that have wood siding as well
You could use it anywhere, the problem is that now you have the place where the new trim meets the cut off siding and it's going to leak unless it has flashing.

d) and there is horizontal siding involved, is it really possible to cut of f bottom 6 inches and replace with trim board or does the siding have to be removed and replaced. (I'm asking this because it would seem awkward to t ry and cut off the bottom of horizontal wood siding at an angle, as opposed to the bottom of vertical wood siding in this situations)
I tried to cut off mine with a circular saw on it's side. It was impossibl e to control it, to get a clean enough cut, so I went to removing it. But then again, my siding section was only 4 ft high because it was where a higher roof met a lower one, so it was easy compared to having to remove full lengths of siding. How big of a gap do you have at the bottom now? Has anyone tried just slipping new step flashing in there and see if it goes up? You might have a siding nail in the way, depending on how close to the roof they kept nailing it. But if there's a nail here and there, I'd just pull the nail. That is provided you have a 1" or so gap.

look acceptable?
I think it will look a little weird. But it will look very weird if you flash the gap, which is the only way I see to keep water out and prevent a real disaster when water gets in, rots the wood, etc.

from bottom of roof near gutter upward. Should we require 3 feet, or 6 fe et?
I believe code is 24" past where the roof meets heated interior space. Meaning you'd go from the lower edge of the roof, 24" past where it crosses the living space vertical wall. And that's for climates subject to ice damming.

. Should we require this only for sides where step flashing is involved, or also require this at tops of roofs that meet fronts/backs of buildings, where continuous flashing is involved?
I would not do it at all. The step flashing is there and it works. And I guess I would do it if you decide to go with that trim board method, but then it better go a couple inches above where that gap is. That will prevent water from just running into the wall, but where does it go then? It will go into the roof deck area, not good.

drip edge is nailed to the fascia above gutter, and tucked underneath botto m shingles. If that's the case, is it important that the nail heads be sea led with caulk, and should they also caulk the top of the drip edge where i t meets the tar paper underneath the shingles so that, in an ice-damming si tuation, the water won't get underneath the top of the drip edge, and then the water could freeze, and force it to come loose, etc?
It should be a sufficient drip edge or gutter apron so that water goes into the gutter and can't get behind it. It's nailed to the roof deck before the ice dam barrier material goes on. That seals it, it doesn't need to be caulked. At the sides of the roof, the drip edge goes over the felt or ice dam material and again does not need to be caulked.

from rotting or water getting behind siding, etc? Ice and water shield? Anything other special flashing? What is the correct terminology?

It's drip edge. It's nailed to the roof deck, over the felt or ice dam. Th e side of it comes up against the fascia board:
https://www.lowes.com/pd/Union-Corrugating-2-38-in-x-10-ft-Aluminum-Drip-Ed ge/4177435
BTW, you are to be commended for asking all the right questions. Most people have roofers doing God knows what and don't figure out the problems until it's too late. There was thread here the other day where new gutter s were hung with hangers that were nailed over the shingles, as an example.
Anything else I can help with, feel free to ask.
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Thanks for the quick reply. Currently the bottom of the siding is too close to the roof line (roofers have commented on this), so some cutting will definitely be required at the bottom of the siding whether the trim board method is used or not.
Thanks for the compliment. I probably obsess over details too much, but most other people would not be asking these questions and just "trust the 'professionals' to do the correct job" lol
J.
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