Building sofits/ extending rafters

[mrcaptainbob]

Well, ambitious...yes, but I think it's the right way to go. I like that idea of removing the decking, especially if it's been damaged. You're right about it opening up the opportunities...The ice dam is a definate requirement here in Michigan. (I'm in Jackson County, was Wayne..) That's a really good plan. THe only places that I would comment on are (from 1st list):
16. Make them flush with the tops of the rafters so as to not kick up the decking. You alluded to that in your 2nd list.
19 and 20 are not necessary. I would think the lookouts would be more a structural need if the overhang were greater than 2 foot.
21. Yes, vinyl is the way to go for this. Very easy to work with and FAR more forgiving than aluminum!
27. Good question. (this means...no answer!)
28. Nail a J channel to the underside of the soffit so that the bottom of the J is against the inside of the facia board and that the short stem of the J is even with the bottom of the facia. The F should then be placed on the wall directly across from that J and the two will provide the parallel channels for your soffit trim.
I prefer to use aluminum for the soffit panels, vinyl for all else. I've had trouble finding vinyl panels with holes punched small enough to keep out the Lady bug type beetles, mosquito's and a few others. The aluminum has a finer brether hole opening that helps keep out these critters. To help your cutting, get a good 2x12x14'. nail some 2x4 to the edges to create a channel. About midpoint build a bridge across that's wide enough for your saw and saw guide. Make sure the guide is 90 to the side rails. Run your saw through the piece and just about an 1/8" into the 2x12. Now you have a nice true saw guide to use for your trim pieces. Reverse the blade in your skilsaw. Use it that way for the vinyl as well as the aluminum. When placing the siding on the house verify where you want the overlaps. They should always be flowing away from the line of sight. Nail up the first piece furthest from the normal approach to that wall of the house. Don't drive the nails hard. The siding needs to float under the fastenrs. Vinyl and aluminum both have a terrific rate of expansion. I don't believe you can over vent the attic. if you use the perforated soffit the entire length would be fine. The ridge vent is a great idea. For the ease of it, just go ahead and do the entire ridge. (this is an opinion....I run the ridge vents right to the roof edge and use the cap ends to seal it. I think it looks much nicer than stopping 2 or 3 feet shy and shingling a slope to the normal roof ridge. My $0.02.)
Are you going to reroof the entire house at this point? Or just the edges you're working on. Would it be possible to do two strips of that ice dam? (By the way, rent a roofing power nailer.)
Get that cold, cold beer.

[Umby]

No lookouts? that would save me a lot of work.
As for re-roofing the entire, I probably should, but I only intend to the eaves and a couple of feet up. I will definately cover the entire project area with that ice shield. How wide is that stuff?
I followed saw guide but got lost at the bridge. Maybe run that past me again. I have a DeWalt chop saw, circular saw, and jigsaw. I guess I will have to use the jigsaw to cut the bird mouths unless you can think of a better way?

[Umby]

Cap'n, this is where I got lost:

[mrcaptainbob]

Great pic! Yep...that's it. Screw a saw plate guide to that. Make sure the guide is 90 to the side rails. The first pass with the saw will trim off the excess of the bridge and make it true also, plus, by passing through the two 2x4's, you'll have excellant guides to set the marked siding pieces. I believe the ice dam is 36". Roll it out the length of the roof. It's plastic backed on the adhesive. Run a nail at the upper corner when you have that in position, then run a nail in the far upper corner. Fold it back long-wise and peel that plastic off and set that half down to the wood. Once it touches, it's there forever! Extra hands would be nice for this part! Yeah, the birdsmouth does make it necessary to use a jigsaw. Still better than handsawing!! Sounds like you're on your way!

[Umby]

Sorry cap'n, it must be me, but I'm not following how this device works. When you say "screw a saw plate guide to that", are you referring to a part on my cicular saw? Does the bridge have to fit in between the 2x4 rails or on top of them? And what does this eight-inch cut go into?

[mrcaptainbob]

That drawing you made, Umby, is exactly what you need. Measure the distance from side of blade to edge of saw shoe-plate. Probably around 3 3/4". Use a 1x10 for your bridge. About 4" from the edge of the bridge set down a 1/4" or 3/8" board to act as a saw guide. That's what your saw will rest up against every time you make a cut, so that should be square as possible with those 2x4 edges. Set the depth of cut so as to engage the bottom of the trough by an 1/8" at the most. The first pass you make with your saw will trim the excess from the bridge, and will also make it square, plus will give you a guide as to where to place your siding pieces. By having passed the saw through the first 2x4, across the trough (that 1/8") and through the back 2x4, you will now have a perfect line to set your marked pieces on. Slide a siding or trim piece under that bridge, mark the legth you want, set it on the cut line, and (with the blade in BACKWARDS) cut your aluminum or vinyl piece. It will always be an accurate 90. If I knew how to make a neat line drawing like that, I could've saved a lot of wear and tear on the finger tips!

[Umby]

Got it! Might want to extend the bridge on both sides a little.
Yah this CAD software is pretty neat! MS-Paint...

[mrcaptainbob]

That's it! And you're right about the extending of that bridge....
Good job on that pic along with the callouts......

[Umby]

A pic is worth a K of words...
I drew this up years ago and I have no idea how legible it will be.
This is my house but it really represents the ceiling joists (16" O.C.) and walls; however, the rafters tie into those, so it serves as decent representation of the rafters in my house. You'll see the rafters I want to extend are on the southwest corner (two walls over my deck), and on the northwest side (at the top of the image). You'll see the walls, both interior and exterior, as double lines; and should be able to see the existing soffits over the eastern side of the house.

Now here's an actual pic of my house, facing east, looking at the gable side of the southern wall. Using my favorite CAD software (yuk yuk), I drew rafter extensions of 12, 18, 24, and 30 inches just to see where the different extensions would tie back into the wall. (note the 24" level on the roof for scale)

With all of that in mind, do think a two foot extension would be too much? When they talk about soffit square area, they never seem to consider: that no matter how big you make the (horizontal) soffit square area, all the air flow still has to go thru the (vertical)square area between the rafters, over the plates, and under the sheathing. Whatever that square area is called, it would seem be the limiting factor. So I guess the question is this: Why make the soffit sq area any bigger than the vertical sq area over the exterior walls under the sheathing?

[mrcaptainbob]

Figure the area of the vent holes. A lot, probably most, of the area is taken by the material surrounding the vent holes. Even plain window screen is somewhat of a windbreak. Just as important as the venting is the protection you'll gain from rain intrusion on your walls. I think two foot is a fair distance. Heck, A friend did that to his house with a bit more of a pitch and only went with (maybe!) 18"! Plus, he used vent panels maybe every third or fourth panel! I like how you did the overlay of the various extensions. Sure gives a 'feel' for what's needed spportwise for an extension. That's why lengthening what's under the shingle area is so improtant. IT relieves that concentrated strain. Good job on that cad view of the house. It turned out well!

[Umby]

Wind driven rain is a valid concern, I see your point.
How do I deal with the aluminum siding if my soffit comes back and hits the wall in the middle of a course of siding? Do I horizontally cut through the siding, or just tack the F-channel to it?

[mrcaptainbob]

Since you peeled the topmost strip of siding off, the removal of the more will be a snap, of coarse. Remove anough panels so as to lay that 'F' moulding against the wall. After that's all in place, install the 'finish' edge molding along the bottom of the 'F' and flat against the wall. I believe they're called stiffeners and are used wherever siding boards are cut and loose their structure. Usually at the bottom of windows. Then just cut your old siding so as to fit up into that stiffener after it's clicked in place. It's secure and tidy. Keep a handy supply of razor knives around. Ideal for the linear cutting of either the vinyl or the aluminum.

[Umby]

What types of nails (assuming no air tools, yet)?
1. framing the lumber
2. the finished facia
3. tacking down the sheathing
4. the felt
5. shingles
6. siding

I'll start tonight after work on the northwest roof exposing the rafters.

[mrcaptainbob]

1. 3"
2. 3" I don't think would be out of line. So what if they'd stick out on the other side....as long as the wood doesn't split. Large heads won't matter as you'll be covering it with vinyl anyway.
2.5 the vinyl trim would be attached with 1" aluminum nails.
3. 2.5". I believe ringshank would be good for this and should be available for an airnailer.
4. Hammer stapler.
5. Not sure of the correct lengths, but there's a proper size for one layer or two layer roofing. Check at the box store for the correct size, unless somebody monitoring these posts knows for sure...
6. roofing nails would work for this. Hand applied...don't snug them down. Allow a nailhead thickness from the panel for movement of expansion/contraction...

[Umby]

Started on the northwest roof last night after work. Pulled off the gutter and when I removed the drip edge I could smell 'attic'. It appears as though the top 2" of facia and the last 1" or so of sheathing is gone. Probably from me beating on ice dams with hammers before I knew how a roof worked. But I had to stop and work with the tarps because of loss of sunlight. You can't see it in the rafter layout above, but I have a valley coming in to the eastern side of this roof section:

To make sure no rain got under the tarp, I weighted them down OVER the ridge and duct taped them to where the gutters were. But I am concerned that rain coming into that valley will run under the tarp from the side. I laid 14' 2x6 along and on top of that edge of the tarp, but I was wondering if there are better methods of holding them down?