roofing construction question (waterproofness)

[Cult Hero]

I am building my garage right now and in the process of roofing it. I currently only have the tarpaper up and will be applying all the shingles tomorrow. We have been getting rain here recently and the roof is leaking a tiny bit in a few places. I am going to be applying some more tarpaper and trying to really get it water tight but I am wondering how water tight should I expect the tarpaper on its own to be?

Should it be completely watertight or is some minor leaking to be expected? I have applied it in the cold and the paper hasn't had a chance to "settle" or "seat / set" as I would expect it to when it gets warmer.

I guess my question is, should I just go ahead and apply the shingles tomorrow, or should I work on making it totally watertight with the tarpaper first?

 

[bmwpower]

Well, I guess the answer depends on how you put up the tarpaper. Did you overlap it? How did you staple it? Was it a windy rain?

See if you can pinpoint the leak to make sure it's not something more serious. If your unsure why it's leaking in a certain area, throw another piece of tarpaper down for good measure. If the tarpaper leaks a little it's okay as it may be due to the staple penetration or a windy rainy day. Either way, the shingles will seal everything up in the end.

 

[snorvet]

I would throw a lttle piece of tarpaper over the leaky areas and then shingle as long as the rest of the tarpaper is not ripped, etc. I had leaks in my tarpaper mainly in valleys and around vent pipes, but no leaks after shingling.

 

[bmwpower]

Do you guys use ice shield on the roof valleys in CA? Just curious...

 

[rodrelic]

Common practice now is to ice shield the whole thing in the snow belt. The old Victorian has to have shingles and iceguard sticky back stuff is under the whole thing, but tin is best in my opinion. My next home will have metal. The log house I built 25 years ago is metal and it's dirty, but it never leaked. And that was before the days of screws.

 

[Cult Hero]

no ice shield here, not needed. The leak is coming from a junction area of the roof. There are about three pitches coming together and it is leaking slightly. It is going to be difficult to put more tarpaper down without making a high spot, but everything I have seen and read so far basically indicates that the tarpaper is mostly waterproof, but the shingles are what really seal it.

 

[rodrelic]

You gotta grab it up, see what it is. The Ice guard that is from the generic home depot, joe lumberyard is rolled roofing with stickyback, still somewhat brittle. The stuff sold at a commercial outlet is in about 3 other grades of quality (or price to be specific). The **** my brother got was phenominal. like a sticky inner tube, shiny foil on one side and a tear off over adhesive on the other. Story is you can mis-nail a bunch and the membrane will close up after you pull the nail. I believe it, don't want to miscue and slap sticky sides together, it's a goner.
I tried to patch up a roof I was tying into with felt and had no luck. too brittle. Pulled it back out and and fit ice guard in the valley to prevent damage. The roofer showed up and did the whole roof and went over mine, doubling the valley. before shingles.
http://www.directimagehost.com/is.php?i=78653&img=Dsc02143.jpg

Pic of the addition on the ginmill next door I rebuilt. Believe me, felt wouldn't get it there, that valley has layers all the way up with a 2" overlap and a run straight down the valley. Shingles are to take the weather.

 

[Cult Hero]

I got the shingles up this weekend. Man that was a lot of work! I will be glad when I can get my free time back It is raining here pretty good right now and no leaks!