roofing advice

Paging Hog

I'll let hog "weigh in" on this one... But depending on how much of a rake it has...I would do the "first course" using bitchathane ('Ice and water shield')...

Well... You be the judge on that one. From the sounds of it it sounds like that poor little garage is "running on borrowed time" somewhat. Perhaps all the more reason for the 'ice & water' shield.

At a 4-12 pitch, uninsulated etc... IMHO... Add a little snow on the roof and a fairly sunny warm day and it's that garages' worst enemy. As small of a structure as it is....regardless of how good the venting is (unless of course the gables are wide open 'daylight'...lol) there is gonna be some potential issues. On most of these style garages usually the rakes are rotted out (moisture working under the shingles)...

Even though it's only around four squares...I like to do a job once and be done with it. From the sounds of it...it will be last roof ever going to go on it...$50 bucks?? Cheap insurance...

Ahhh...It's up to you to decide!

If its one of those "ready to fall down" as you stated. I would suggest just use roll roofing due to the condition of the shed and the low pitch roof. Roll roofing is cheep and last about 8-10 years. If you want to use shingles, one row of felt would help but using ice-shield would be better.
Firewoodguy

Naghhh! Say it ain't so! lol

Old building with an old roof??? Been there...done that. It really gets fun when you have to decide "Should we put down plywood and 'do it right' or skip that because the thing can barely hold the weight it has on it now???"

Yeah..."Fun and games" when it comes to roofing. My house is 100+ years old and has a slate roof, luckily, (knock on wood) it's in pretty good shape given the age. I'm always on the lookout for slates on the ground...in ten years i've only seen three (pieces) anyway.

Talk about fun??? Slate is definately good for that!

I was talking to an 'old timer' in the neighborhood..."You got a good roof there kid...take care of it". He said to me.

Having a slate roof can cause some concern....but at the same time it's a good piece of mind too. Solid as stone.

On an old shell of a garage? Why waste the extra money? First off you have no gutters. The only reason for Ice & Water shield at the gutter edge (eave) is for when gutters are installed and in the winter, melt off from the roof above the gutter runs down, refreezes in the gutter to the point the gutter fills to top with ice & then the meltoff hits that ice damn and backs up under the shingles. If you have not gutter, no Ice & Water shield needed. Theres nothing to create an ice damn, so no backing up of water & ice. I bet you get some major icycles off that garage?
Save your money. Unless your going to install gutters any time soon. Plus its not heated, so no escaped heat from soffit area melting anything.
Save your cash man. If the garage has no leaks over the years, and that wood is not stained or rotted at the bottom. Then there is your answer.
I will agree that 4/12 ain't sheet. I used to use a 4" exposure on 4/12 pitch roofs. An added inck of coverage helped alot. The manufacturers used to spec no less than 4/12 pitch. And 4/12 & 5/12 used to be spec's to a 4" exposure instead of the normal 5". This is standard shingles sizes. The metrics are like 5-3/8" exposure. Something like that. Long story short, no leaks or stained wood, no Ice & Water needed. If you find rot or stains. Then you may want to consider it.

Save yourself some grief and don't consider roll roofing. I will merely say it is the Volzgang (spelling) of the roofing materials.
I seen it recommended, just my opinion of course, and have tore enough off. I had to redo all my old mans valleys due to roll roofing being used by builder.
Also, in your travels look around and you won't seem it much, and when you do, it on a doghouse, or dilapidated shed etc.
Its a poor mans roof & you will only get what you pay for.

Slate roofs are the Cadillac of roofs. Keep it maintained and it will outlive you & your kids & grandkids.

I hate to say it, but more info needed LOL.
I missed the part of it leaking in several ares. What are the rafters centers? 16" or 24"? What thickness (I'm guessing plywood) or if old enough planks?
The problem with a low slope shingle roof is, if the deck sags between the rafter, then it creates a small pool, and with not enough slope, the water looks for the lowest spot to run to. If the roof is leaking higher up from the eave, then ice & water shield will ohly help down there, but not where the leaks up higher are. If the shigles are deteriorated enough, the daylight you see might be from missing chunks of shingles and not necessarily the slope.
I suggest tearing off one side (prolly the worst side if there is one worse than the other, and see exactly what you are dealing with. Just get some 1" x 3" and a good tarp when done tearing off, and lay tarp out & nail the 1"x3"'s around the entire perimeter and vertically down the center in a few rows. that will hold the fort down until you decide your course of action. If I lived closer I'd be happy to come take a look & prolly end up helping. If you get stuck for help, I can prolly set a weekend away and come up.
Ok, if the holes are small, and you really just want to keep the cost down, just use some heavy gauge metal, like the stuff we make block off plate at HD or Lowes, and cut a few inches larger than the holes and nail the patches over the holes, then you can shingle over them. If the holes are large & numerous. You going to have to replace some wood. If the leaks are truly due to the low slope, you might want to consider Ice & water shielding the hole thing before shingling.
I have a feeling your going to find a mixture of really badly deteriorated shingles, with decking showing through & a few sag spots in the decking itself.
As far as 4" exposure. I for some reason think the shingle manufacturers did away with warranting the 4 or 5/12 pitches & less. Standard expaosure ( the part of the tabs you see) is 5", sometime 5-3/8". Depending on standard or metric shingles. As I said before on 4/12's it was spec'd to have a 4" exposure. Which means there is 1" extra from each shingle under the next two courses. Makes it harder for water to back up under the shingles and run under the tops.
If I am making this more confusing, let me know & I'll draw a picture. As far as the starter course (upside down shingle)at the eave or first course. Yes they are necessary. If you were to just put your first row or course on without a starter course, the seams between the singles would leak onto the decking because there is no courses under it.
The starter course is merely a shingle flipped upside down, cut 6" off the end before you run the first one. Don't forget to leave 1" hanger past the rake or side of the roof. This overhang keeps water from running under the sides as it runs down the roof. Some put a vertical run of shingles along the rakes also, I do not usually. Creates a hump when you run the courses over them. Leave an extra 1" at the rake also. Chalk lines really make this much easier.
You will pop your lines so that as your shooting your shingles, the exposure will be 4" instead of 5". I used to pop lines at every 20" to follow for 5" exposure, so every 9 " or 19" should give you 4" exposure. Its been a while, and easier for me to do, than explain. And verticals were always 29" & 35" from the side I start shooting at. which for me is right to left since I am right handed. This is for 3 tabs. If you use dimensionals, no tabs, means no pic lines, and less space for water to find. Dimensionals are easier to put down, & more easy to hide any oops. More expensive though.
You may have the rake mixed up with the eave. The rake is the side. The eave is where a gutter normally would be hung or bottom in other words.
Starters have never since I have known come with the shingles. If you are using 3 tabs, you just flip them over and use as starters. Or Ask the supply house if they have any junk bundles you could buy for starter strips. Sometimes they will give them to you. Color doesn't matter as they are not seen.
12' x 22' is only a 2.64 sq. Thats a very small roof. Order 3 to 3-1/2 sq for the job. For waste, hips, starters, and some left over for a , just in case blow off, or limb hit the roof. I'm sorry if I am bouncing all over, I am wooped, did my plumbing & put up another wall of 8" t&g;pine. Back hurts & just now finally chillin.
Ask any questions, I'll answer best I can. I'll draw a pic, whatever ya need. If it would be easier by phone, just PM me. I have free long distance. Well not free, but unlimited. What is easy in my mind from doing over & over, might not be as easily understood as I am thinking it is. However I can help, just lemme know.

When ya get a chance post a few shots of the garage. I can guess at the pitch with a good photo.

Oh crap I forgot one more thing.
Since I have retired from roofing. Some new products have come out. I don't know alot about them. But one in particular might be right up your alley.
Heres a link to the site. Called Shark Skin underlayment. I have been told its price is in comparison with tar paper. Thats hearsay, I cannot say for sure.

http://www.sharkskin.us/tek9.asp

You prolly already know this but, if you can see the decking & rafters from underneath, take not of where real bad spots are, and at least try to walk on the rafter up top when tearing off. I have gone though roofs up to my armpits, and its not fun. Almost always something, Nail, wood pike, etc gets ya good. Just be wary before you know were the bad spots are. I seen guys fall from 8 feet and do some serious damage. Its not the fall, its the impact upon landing.

I'm getting 'dizzy' following this one...lol

Hog... He also stated above he has aluminum ice barriers on one side.

I'de be willing to bet the eaves are 'junk' (fairly notorious on them thare old one car garages).

80 year old garage??? Betting on a 'plank deck'. If thats the case...see if it will 'hold a nail'...if it does...buy a few 1 x 6 rough cut boards and just "replace the horrible spots". Plywood? (you said it yourself Web...the garage is a potential 'tear down candidate') Forget the plywood...if you do decide on plywood...go with 1/4 Loo (laun?) just to keep the "smooth look" (and keep the weight down)...but Yeah...as Hog suggested...

Some pictures would help in the discussion...

Rip it...Take some pics...and then tarp it.

Web??? Out of curiousity??? Is their place close by your homestead or is there some "travelin" involved???

Agreed on the planks. Which makes it easier. Problem might be, they may be true boards. If thats the case replace the bad with One by's & fill in the low spots with a shingle. Usually makes it perfect level with the old true planks.

Decking look pretty damn good for 80 years old. I bet you found the nails don't come out of the planks as easy as they do in plywood. And two roofs worth makes it even more a pain in the arse. That pitch by looking at photos mind you look s to me like at least a 6 maybe more. No need to short course. Just run 5" exposure. Theres plenty of pitch there, and that no wheres near a 4. I would bet somewheres between a 6 and 8/12 pitch.

At the peak, just run both sides up enough that your tar line is about 1" or more above where your hips will cover. Yes just cut the 3 tabs into separate hips. Chalk a line on one side, and as you nail the hips on, fold them in half, not creasing them, just a nice arch, they will lay better over the peak & be much easier to line up.
Start the hips from the furthest point (back?) of the roof from normal view on the ground(front?). That way you don't see all the lil seams & lines on the hips. If your not running ridge vent, then the side you finish shingling on, just let the top flap up & over the peak back to the other side and nail it tight. Just make sure its not so long that it will hang out the bottom of the hips when you install them. I doubt you need any ridge vent, its not living space. The gable vents should do fine. If you really want to put ridge vent on, if there is soffit under the eaves, it must be vented for the ridge vent to be effective( the two go hand in hand, without one the other is useless). And yes you will want to rip (cut) about 1"-1-1/2" off the top board each side. I suggest, when you side the the garage. Get a good size triangular gable vent for each rake side, cut holes where existing ones are, and install the newer bit larger gable vents. That should be plenty. Those ones there look like heating duct registers, and are a bit small.

If you have 2 step ladders and a nice plank, it will be easier to run the first few courses from there. Then either use 2" x 4"'s or roof jacks. First off, either one you use, I wouldn't nail through the new shingles face. I lift the tabs up where nailing and slide the jack or board up under enough that when I nail in INTO A RAFTER, when I am done, I pull the nails from the board, then just lay the tab back down & wallah holes covered. If your using roof jacks, they slide off the nails when removed (don't pound the nails home) and then after jacks are removes, then pound nails home. Both done under a few tabs, then no holes and no caulk needed. If you do want to just nail a board through the shingles, after pulling the nails, put a lil caulk under the tabs that were nailed through, then just set the tab back down over the caulk. It will ooze out, wipe excess away. And if you want to get real fancy, I always rubbed two shingle tabs faces together and rubbed enough of the colored granulars off for a handful, then sprinkle it on the top of the caulk, and press in a lil bit. Once done, you will never be able to find that hole or caulk again. Lots of tricks of the trade LOL.

Anytime, glad to help.
You could get the cobra vent or similar, spaghetti like ridge vent, that you unroll , tack down, and shingle over. You can use the tabs for hips as usual. If your not real big on looks, and I know I said in other threads to not use, But economically, the aluminum 10' length ridge vent is prolly cheapest. It is only a garage after all. And no hips needed. just cut your plywood to have a space for air as usual, then nail the aluminum ridge cap over top, caulk nail heads, Done. I would at least use ring or twist shank nails with that stuff. Regular roofing nails tend to back out after time with this ridge vent.
If you nail a few boards strategicaly horizontally across decking over the tar paper as you go. You can set your bundles of shigles out and not have to go up & down a ladder. But on an 2-1/2 sq roof. Your only looking at 10 or so bundles for the whole job anyways.

Would a sheet metal roof worked here?
The snow usually just slides off of mine after a day or so.