Roofing discussion!!!

[nwut05]

Hello all, I just wanted to get some other opinions and objective discussion about a situation i came across this weekend. I observed a roofing contractor who installs a lot of tin roofs. He was doing something i thought was maybe worth discussing. I observed him working on an existing roof that was shingled and he was putting new tin over it. Now here is the questionable part. Instead of rolling the tar paper/felt the length of the house, starting at the bottom, and overlapping to the eve. He was starting at the end of the house and rolling from one side to the other overhang to overhang, or gutter to gutter per say, overlapping as he went about 8 inches. Now i do know this contractor somewhat, and confused about his new tar paper technique, i approached him. I had to ask him why he was doing that? and his response was it did not matter which way he ran the tar paper over existing shingles???? and after some friendly discussion i decided the best thing i could do was move on and not try to change his mind anymore! So what do you guys think will his way work. i personally think it would open up more opportunity for leaks????

 

[BLSXJ]

Well a quick look found The Purpose of Roofing Felt - Is Roofing Felt Necessary? - IKO Roofing

running the tar paper vertically, would eliminate the water proof benefit

but it would still help even out the shingle surface.

my vote was either it doesn't need to be done... or he was doing it wrong.

 

[ovrszd]

It certainly wouldn't be easier to run it that way. Well, to me, it wouldn't be easier.

So this completed roof has a layer of tar paper, a layer of shingles, a layer of tar paper and tin sheeting.

I can't see that the newly added layer of tar paper is doing much anyway?

And if the roof develops a leak it probably won't breach the vertically ran, 8" overlap anyway.....

I'll yield to the expert and say it doesn't matter.

 

[davedj1]

The paper isn't for waterproofing, it's simply to keep condensation from dripping inside. If it already has a shingled roof ( I wouldn't put tin over a shingled roof) I see no need to install tar paper. If the roof shingles are bad enough to need tin, they should be torn off and thrown away.
Any of you seen paper on a pole barn? If so, how was it put on? It would be difficult at best to run it laterally.

 

[Dwellonroof]

The tar paper is actually a slip sheet at that point.
It is a barrier between the granular surface of the shingles and the underside of the metal roof.

 

[Steppenwolfe]

I wouldn't run metal over shingles... spend a few bucks and do it right.

 

[ovrszd]

I wouldn't run metal over shingles... spend a few bucks and do it right.

If you are gonna say that you should describe "right".

 

[RalphVa]

Hello all, I just wanted to get some other opinions and objective discussion about a situation i came across this weekend. I observed a roofing contractor who installs a lot of tin roofs. He was doing something i thought was maybe worth discussing. I observed him working on an existing roof that was shingled and he was putting new tin over it. Now here is the questionable part. Instead of rolling the tar paper/felt the length of the house, starting at the bottom, and overlapping to the eve. He was starting at the end of the house and rolling from one side to the other overhang to overhang, or gutter to gutter per say, overlapping as he went about 8 inches. Now i do know this contractor somewhat, and confused about his new tar paper technique, i approached him. I had to ask him why he was doing that? and his response was it did not matter which way he ran the tar paper over existing shingles???? and after some friendly discussion i decided the best thing i could do was move on and not try to change his mind anymore! So what do you guys think will his way work. i personally think it would open up more opportunity for leaks????

Don't think I want to use that roofer. Don't like the idea of putting tin over shingles. Not the most even base. Certainly would have want him to be rolling the tar paper vertically.

Ralph

 

[TnAndy]

The tar paper is actually a slip sheet at that point.
It is a barrier between the granular surface of the shingles and the underside of the metal roof.

That is the reason I'd use tarpaper over shingles IF I was going to install metal over shingles....which I wouldn't personally.

 

[Diggin It]

'A few bucks' could double or triple a job cost. I've got over $7,500 in my metal roof and that's over existing shingles. No way I could have afforded a full tear off. I don't know how long it will last before problems develop, but I hope I'm long gone before then.