Another rofing question about flashing


Another question if I may -

My neighbor just got a new roof and I whatched what the roofers did around the chimney. When they tore off the old shingles I observed flashing around the sides of the chimney. It is a wood chimney above the roof line and the original roof had what appeared to be aluminum flashing stuck under the sides and top and bottom of the chimney and it seemed to have about a foot sticking out. I don’t mean step flashing, I mean a solid piece of aluminum running down the sides and also pieces along the top and bottom. Apparently the aluminun is tucked under the wood fascia of the chimney.

The new roof guy just put his new felt under the flashng and then nailed the new shingles over it. I observed that he nailed the shingle such that every shingle next to the chimney did have nails such that I am sure that he just nailed through the flashing as he nailed down the shingle.

This is not correct is it? Shouldn’t it have been step flashed or is his methodology good enough. Apparently he just did it the way it was done originally and I presume that it hadn’t leaked.

Is this a common practice? Does it work or will it eventually leak. It did look a lot less involved than the step flashing>



its not right,if need too,you take off wood facia and re-step and new front and back pan



It is a short cut. May leak - may not. Depends on how he did it.

If he laid the shingles in a thin bed of roof cement the chances are good that there will be no problems.

If he chaulked along side the chimney his chances are not as good put still may never leak.

Done to eliminate any chance of a leak step flashing should have been used.


I beleive what you are desrcribing is an overflash along the chimney sides. You need step flashing integrated into the shingles layers to correctly prevent leaks.

Sounds like a 2nd shortcut applied again. Good luck!


sorry northeners,
but step flashing is not required or needed in many parts of the country.
poster were are you from?



Gweedo what on earth are you getting that from. For god sake it states step flashing on the back of the shingle wrapper for crying out loud. I cant beleive i just was reading this.

Step flashing is always needed on any vertical wall going down a roof. Sealant better known as flashing in a tube is not the correct way of doing things. ANd even then it has to be done correctly.

Here is the install instructions that are on the back of every gaf shingle wrapper:

Oh snap they say step flashing.


Step flashing is OUTLAWED in florida!!!

Hundreds of roofers, hundreds of builders and no one uses step flashings.

Why? because we have the government telling us how to install roofs. And the government knows better than the roofer.

All metal (wall flashing and valley flashing) has to be installed and city inspected before the first shingle can be laid.

Since step flashing would need to be installed at the same time as the shingles–step flashing is outlawed.

Government intervention and ridicules prices are coming to your town soon.

Hope we can believe in.


sorry gtp but your just not rite on this one.
nothin has step flashing on it down here.

i agree with ya though, its a damn good , if not the best way to flash somethin.

one could argue were a little crazy down here.
but we do use long peices of 4"x6" l flashing up
walls, stick the shingles to one side and put siding over the other.
i can post some pics if you like.



gweedo - yes please post pictures.


What you are describing is called “continuous Flashing”, If done correctly it will last the life of the roof.

Stepflashing is better but properly done continuous is perfectly acceptable.

If you must have step flashing simply pay your roofer more to remove the siding to install steps.


A step system can outlive several shingle systems and also has a breathing quality. If done right, step systems are easily salvaged for the next re-roof.

Oh sure, A curb can be made to work, but unless you can keep your nails back four feet, it involves either tar or ice belt, which makes a mess and doesn’t hold reliably.

I,ve blown open plenty of both. The curbs had lots of leaks and rot. Almost all the step systems cleaned right up and wove right back together.


We just fixed one today that had continuous flashing.

The roof was well done, the valleys were tarred down and everything.
The workmanship was better than average.
This particular roofer liked continuous flashing.

It was leaking because it wasn’t stepflashed, and/or because there was no Ice & water shield extended up the wall.
The leak did extensive damage to the very nice genuine hardwood floor requiring complete replacement, approx 300 sq/ft.
There were also the usual insulation, drywall, and mold issues.
In the end this relatively small leak caused several thousands of dollars in damage.

The continuous flashing on the chimney worked fine, there was no leakage at all.



That previous roofer didn’t hardly use any cement at all.
I see it barely on there. That cement didn’t do anything. It was leaking since the first rain.

If you’re using continuous flashing- you need continuous cement. Also Cement it solid between each shingle for a good job.


That previous roofer didn’t hardly use any cement at all.
I see it barely on there. That cement didn’t do anything. It was leaking since the first rain. [/quote]

Being a warm weather roofer I can understand why you would think this.
The shingles were set in approx 4" of mastic, you can’t see that because when it is cold mastic usually comes cleanly off the metal.

It was leaking because of ice build up.


True, it is always better to clean the flashings in the morning when it’s cooler.(here)
Its unbearably hot here most of the time.
Its 69 degrees at 11 am as we speak. So thats great.
But it is short lived.

It looks like the edges of that flashing
(we call it “5x5” here) is serrated.
Am i right or is it just the picture?

Even with that top quality grace,
Im thinking that some of that bottem area could use some cement on top of the nail heads too.
Much less expensive than using SS, copper.

You really have to treat that area as though it was a flat roof that holds water.

I didnt realize till just now how much snow/ice really does help business for yall.
Every winter homeowners must be freaking out.


Those pictures make me wonder how much architects actually think before they draw something up. Perhaps its just me but I think on houses where the valley runs into a side wall such as that, it has the potential to be a problem. All the snow,ice and rain that can accumulate there will always cause leaks unless it is done perfectly the first time.

This may seem weird to some of you but whenever I come across those situations where they have continous flashing like that I nail it down flush to the roof deck, cement over the nail holes, lay grace over the flashing 18 inches out, then do regular step flashing all the way up. When the siding is off like that, I will nail the flashing against the wall so no holes are put into it then I cut the shingles into thirds so there arent any seems too close to the wall.

Most likely seems weird to some of you or maybe even normal but I figure in areas like those you have to do a little over kill because I know they become problems up here.


The metal is just cheap mill finished coil stock, it’s not serrated.

The Grace performed as it should, it just wasn’t wrapped up the wall.

When we re-shingled it we used copper nails in the lower 4’ of the valley, water does tend to stand there…
It is an 8/12.
The Grace on the wall that you see in the picture is from an attempt to fix the problem last year when it first appeared.
Last year it was just a spot on the ceiling.

After we stepflashed the wall we removed the Typar and applied Grace to the entire wall lapping onto the steps.
It only took 8’ of material.

I have nothing against continuous flashing, I re-use it when it is in good condition and have no problems with it.
I do think that step flashing is far better and is what we always install as new.
This is a rare example of properly installed continuous flashing not working, it usually works.

With the continuous flashing you need to use a fair amount of mastic, this makes it much harder for the next guy to remove without damaging it.
Step flashing doesn’t require any mastic and if properly done can be reused more than once.

It would be nice if more roofers would think about the next guy.
Something that appears to be overkill at the time is in reality very good for the building and the next roofer(s).
Wrap Ice & water shield or at least felt up all of your walls.
If the next roofer is smart enough to not cut the underlayment at the wall, that wall will never leak.
Even if he is an idiot that doesn’t know how to flash a wall.

But there is money to be made fixing others mistakes…


I truly believe that if you step flash each course using an individual tin shingle on each shingle course-that you would not have to use felt nor roof cement on the whole deal. We step flash each course of shingles and have never had a problem of roof leaks on any side wall.

But that is just one roofers’ opinion backed up by many years of roofing experience.


Step flashing won’t leak. I tiny dab of mud at at the break of the L before setting the shingle is all that’s needed in Fla. Office workers came up with it’s current code.

Take a look 1/2 way down the page. It’s from the inside of the attic. Real crap job with the step flashing. Could be the Raccoon did it all. BUT, notice, all the damage is from water soaking inot the siding from it’s bottom. No trace of water on the rafter. Or felt, or I&W.,266.15.html


[quote=“gweedo”]sorry northeners,
but step flashing is not required or needed in many parts of the country.
poster were are you from?


In the north we always step flashed. In the south they use “wall runners”. No mastic no metal cards. 1 piece of metal 4 inches up, 4 inches on the deck with a slight bend for water run off like valley metal. No nails through the deck.