# Step Flashing vs. L-Shaped Flashing



## Knighton (Feb 5, 2009)

Which one is the best? What are the advantages and disadvantages of each. 

I have used one long L-Shaped flashing in the past with a slight lip that rests under the shingles. I was having some counter flashing made a a sheet metal shop and the guy there told me that step flashing was the best base to use.

Merry Christmas


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## KennMacMoragh (Sep 16, 2008)

One isn't better than the other, they're made for different locations. L flashing goes where the top part of a roof butts a wall, step flashing goes where the side of a roof butts a wall.


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## Kgmz (Feb 9, 2007)

The uses are just like Ken posted.

Don't use the long L flashing on slopes because the water it catches will just get under the roof eventually. Step flashing points the water back on top of the roof at every step.


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## izzy (Oct 6, 2009)

Since we are on the subject of flashing. My roofers always step flash and then counter-step flash, but I also see a lot of straight line counter flashing over the typical step flashing. Which of these two methods are better and why?


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## stuart45 (Oct 7, 2009)

http://www.justlead.co.uk/news/Page-2.html
Some usefull videos


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## Knighton (Feb 5, 2009)

izzy said:


> Since we are on the subject of flashing. My roofers always step flash and then counter-step flash, but I also see a lot of straight line counter flashing over the typical step flashing. Which of these two methods are better and why?


 
I've seen the straight counterflashing installed and on certain chimneys it looks okay. I think there would be a problem cutting straight through the brick rather than just in the joints. I would think there could be some structural issues?


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## buddy110 (Oct 3, 2009)

Knighton said:


> I've seen the straight counterflashing installed and on certain chimneys it looks okay. I think there would be a problem cutting straight through the brick rather than just in the joints. I would think there could be some structural issues?


None. The brick is strong enough to accept a 1/4-3/8" cut in it. Then using some Karnak #19, glue it in place over top your step flashing. Finally run a clean bead of sealeant on the upper lip. 
I also use I&W underneath all of it and let it exit over top of the head lap area of the shingle. That way anything that gets past your flashing exits on top of the shingle. :thumbup:


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## Roofer Dan (Dec 21, 2009)

as stated above, the type of base flashing used is "application specific". step flashing for where the end of a shingle hits a vertical plane (wall, chimney,skylight, etc.). apron flashing where the "top" of the shingle hits a vertical plane. 

so far as counter on a brick wall (or chimney) i prefer to stair step the counter with individual counter plates. besides being the "old school" way of doing it, i think it looks better, and ain't as hard on my grinder blade. 

stucco gets strip countered tho.


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## buddy110 (Oct 3, 2009)

Roofer Dan said:


> as stated above, the type of base flashing used is "application specific". step flashing for where the end of a shingle hits a vertical plane (wall, chimney,skylight, etc.). apron flashing where the "top" of the shingle hits a vertical plane.
> 
> so far as counter on a brick wall (or chimney) i prefer to stair step the counter with individual counter plates. besides being the "old school" way of doing it, i think it looks better, and ain't as hard on my grinder blade.
> 
> stucco gets strip countered tho.


 
I agree that's the best looking way to do it!


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## Grumpy (Oct 8, 2003)

izzy said:


> Since we are on the subject of flashing. My roofers always step flash and then counter-step flash, but I also see a lot of straight line counter flashing over the typical step flashing. Which of these two methods are better and why?


Thank you someone for bringing this up.

Either is acceptable IF and only IF they are cut into the masonry. Most guys around here are going european style, meaning it's a straight piece of flashing caulked on the top but not cut into the masonry. I knew a guy from Michigan that did a straight piece of counter flashing but it was cut into the brick first using a circular saw and masonry cutting blade. I find this method to be acceptable, but I do not accept the european style since the flashing will leak when the caulk cracks, since the caulk is the only thing keeping the water out. Expect leaks on a european style counter flshing within 5 years.

Then there is the stepped counter flashing where the flashing follows the countour of the brick mortar joint. If the stepped counter flashing is done properly the mortar joint will be ground into about 3/8" to 1/2" deep. On each one of those steps, a metal flap will be bent about 3/8" to tuck into the chimney then be caulked. This is called "raggling". This in my opinion is the only proper way to flash a masonry wall or chimney. However I have seen many guys fake it and never grind the joint or bend the flap. At first glance it looks proper, but when the caulk cracks = leaks. 

The only time we do the straight flashing is at a stucco wall, or when the existing flashing is straight and the masonry already cut (not often). 


Why do you think more guys do the straight flashing and/or european style? It's faster, and that's cheaper, and you don't have to pay a skilled roofer, and that too is cheaper.


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## English Roofer (Dec 22, 2008)

Grumpy said:


> Thank you someone for bringing this up.
> 
> Either is acceptable IF and only IF they are cut into the masonry. Most guys around here are going european style, meaning it's a straight piece of flashing caulked on the top but not cut into the masonry. I knew a guy from Michigan that did a straight piece of counter flashing but it was cut into the brick first using a circular saw and masonry cutting blade. I find this method to be acceptable, but I do not accept the european style since the flashing will leak when the caulk cracks, since the caulk is the only thing keeping the water out. Expect leaks on a european style counter flshing within 5 years.
> 
> ...


While i dont! consider my self a european i do consider my self a roofer, there is no excuse for not steping your flashings, not only is it the right way to do it it looks a damm sight neater i also bend my flashing in to the brick work 25mm(1"),this is held in place with a rolled lead wedge which then the gap is filled with a product called leadmate which is a durable flexable caulk, the only time i do a continuse flashing is when it runs parrael with the brick work, ie the front apron cover flashing.
Cheers
Dave


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## CookeCarpentry (Feb 26, 2009)

I think the stepped counterflashing, by far, looks the best.

What do you guys do on a re-roof, or repair, where someone cut a straight kerf and installed a straight piece of counterflashing?

Re-use the kerf, make new stepped counterflashing?


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## English Roofer (Dec 22, 2008)

CookeCarpentry said:


> I think the stepped counterflashing, by far, looks the best.
> 
> What do you guys do on a re-roof, or repair, where someone cut a straight kerf and installed a straight piece of counterflashing?
> 
> Re-use the kerf, make new stepped counterflashing?


I always re-new the flashing stepped or not on a re-roof just because i know it will be right and its my name im putting to the job, if i come across a job that has had its flashing cut straight up(Kerf as you caled it) the chimney i re-cut it to step flashing.
Cheers
Dave

Below are some photos of a bay porch we re-did because the H/O didnt like the flashings, you can see where it was cut in to the brick work straight andafter when we stepped the flashing.


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## Grumpy (Oct 8, 2003)

CookeCarpentry said:


> I think the stepped counterflashing, by far, looks the best.
> 
> What do you guys do on a re-roof, or repair, where someone cut a straight kerf and installed a straight piece of counterflashing?
> 
> Re-use the kerf, make new stepped counterflashing?


If someone cut it straight we are pretty much forced to re-use it or tuck point it and let the mortar cure then do the flashing how we'd like. For logistical purposes we'd just re-use it, kinda as I posted about above.


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## Roofer Dan (Dec 21, 2009)

even when they've cut the reglet (the proper term for the "groove") for continuous strip counter, i still stair step it. most times it's been re-sealed many times with everything from geo-cell to tarnak, and the bricks just above the reglet are a nasty mess. 

i just beat it all off with a hammer and flat bar, cut my new reglets in the morter joints w/ a 4 -1/2" grinder (w/ a diamond blade) and flash over the whole mess. i usually go every other morter joint. i make indevidual (triangle) counter plates tucked in 3/8" into the reglet. i put a bead of caulk on the back (both vertical and horizontal) stick it to the chimney/wall (lip going into the reglet, of course) and nail it w/ 1" concrete nails. seal up the outside w/ geo-cell 2300. 

hope all that made since.

even tho, i don't use it, the continuous method is approved by certainteed (meaning it's in their msa manual)

btw, English Roofer: you sir are a craftsman!


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## apehangeralfy (Oct 26, 2008)

Also depends on the area you are working...

We use straight L aluminum wall metal, but it get 6" of roofing cement and every shingle gets counter bulled...

With the way they have us tied up with inspections step flashing is almost a lost cause, houses need to be fully metaled all flashing's nailed off before any shingles are laid. What else can you do???


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## Tom Struble (Mar 2, 2007)

thats got to make it difficult for the next roofer:sad:

Tinner has used the continuous flashing before i believe,some special details to make it work


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## theroofinggod (Jun 28, 2007)

He`s referring to a continuous flashing like the side of a skylight might have.once it`s tarred up the way they do,It`s gonna be easier to replace all the flashing anyway ,As opposed to cleaning it anyway


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## Big Dawg (Dec 25, 2009)

Knighton said:


> Which one is the best? What are the advantages and disadvantages of each.
> 
> I have used one long L-Shaped flashing in the past with a slight lip that rests under the shingles. I was having some counter flashing made a a sheet metal shop and the guy there told me that step flashing was the best base to use.
> 
> Merry Christmas


Hey Knighton, In my humble opinion, it depends on which roof you are installing with what metal. If you are using composition, slate, shakes, wood shingles, etc., and you are talking the pitched run of the roof, then you have to step shingle those applications, as per manufacturer's specs. If you are using tile, then you would use the continous "L" metal, with a hemmed edge, under your tile products on the pitched runs. All products use an "L" type, designed metal, or lead metal, on top of the hortizontal planes, such as at the siding junctions, etc. There are also some considerations given, when making your decision on which way to go, based on the area and whether or not you have snow loads, as well. So ask a professional in your area and he should be able to give you the best scenario, for the particular product, in your area.


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## tinner666 (Nov 3, 2004)

tomstruble said:


> thats got to make it difficult for the next roofer:sad:
> 
> Tinner has used the continuous flashing before i believe,some special details to make it work


Yeah, I've been stuck with channel flashing a few times. It takes a special technique. I won't bother to explain it.


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