re-roofing a small shed-

hello people- I have a little problem- I built a shed 12 year ago with the aid of a friend and now the roof seems to be leaking BUT I am not really sure where- I wold like to re-roof over the existing shingles- I only have one layer there now- BUT I not being a roofer need some step by step advice-I am hoping this will fix my leak- I am trying to attach some pics but it is giving me errors?
The roof is a flat roof with a slight angle so that the water flows off and it has flashing at the back that is bent so that the water flows away from the back of the house. It seems all sealed up BUT yet I am still getting some drips inside??

What I am trying to do is just re-shingle a second layer over the first later to see if that stops the leak-- But I need to know if I need to re do the tar paper or just lay the shingle over the other shingle- and how to start and how to finish?-

I would love to send the pics BUT I am getting an error-- any ideas of how I can attach the pics from my iphone??

 

You say the roof is flat... with a slight angle. My guess is that the roof slope is too low for shingles. Tell us what the pitch is. Is it 1:12? 2:12? 3:12? Or what?

Also for a roof so small, you should tear the old shingles off. Only in this way can you inspect the damage to the sheathing, put down new felt paper or ice and water shield, etc.

 

I would not put tab shingles on a roof with a pitch less than 4:12. For a shed you might squeek by on a 2:12 pitch but I wouldn't. For a flat or nearly flat roof you should consider a membrane, hot mop or some other system intended for flat roofs.

Looking at all the snot/caulk it looks like you might have had leak problems in the past. Now would be a perfect time for a proper repair and re-roof. Tear off the current shingles. Possibly add a layer of sheeting so you can have even a couple inches of overhang. And apply something appropriate for a low pitch / flat roof.

 

AS stated above. OR you can build up a bigger pitch angle then use tabbed shingle. After removing existing shingles and making sure old sheathing is good, use a few 2 x 4 's to make a fake roof so to speak over the existing roof.

Rough sketch

 

Every major shingle manufacturer has a special set of instructions for roofs that are between 2:12 and 4:12.... and those instructions specify the procedure for underlayment. Personal preference aside, it's perfectly normal to use shingles on anything from 2:12 up.

However no mfg will warranty a roof less than 2:12. Yours looks too flat for shingles, buddy.

 

Is the shed built that close to the house? or is the wall next to the shed something else
A metal roofing might be another option for an almost flat roof.

 

thank you for all the replies--- I am having a roofer come over today for an estimate- hopefully not too much-- I will ask him all those questions-- and thank you all-- But this is definitely not a job for myself--