What's wrong with Continuous flashing instead of Step?


#1

Several of the “PROs” slammed me in a previous post and called me basically everything but a Straight, White Man.

Intelligent responses only.

I believe continuous flashing is a better system. In my experience, the weak link of step flashing is where the walls meet the roof. Without bull(plastic, tar, mastic, etc.), these step flashings tend to seperate on the wall and that’s where the leaks occur. In my experience.

Continuous flashing solves this problem. This flashing is cupped and is installed above the felt. It is also caulked to prevent water entering under the shingle. I have even seen guys glue the shingles to this continuous flashing. The important thing is to shoot out this flashing(step it) on the last shingle.

This method also allows for flashing inspections before the shingles are applied. Permit inspectors in my parts are also requiring a 1 inch gap now from roof to siding. They want to see the shiny metal running along the wall and I have had framing contractors chastise me for painting flashing before the frame inspections are done.

I welcome intelligent debate and opinions…


#2

It doesn’t work.

"I believe continuous flashing is a better system. In my experience, the weak link of step flashing is where the walls meet the roof. Without bull(plastic, tar, mastic, etc.), these step flashings tend to seperate on the wall and that’s where the leaks occur. In my experience.“
You weren’t installing them correctly.
They get bent at 80 degrees, pushed into position and nailed. And with only 5” of travel, the water doesn’t have time to cause any trouble. And no tar is necessary.
Et-al.
I have yet to see a properly installed step flashed wall leaking. Improperly? Yes.

Like the pix I posted before, channel clogs up. And NO roof requires tar to do it correctly. Except in Fla. where the roof specs are defined by some HO Commitee of legislators, instead of roofers.


#3

Its fine if your in an area that dosent rain. They used to make skylights like that “they were called self flashing” they took them off the market. Tile roofing will somtimes have what we call “channel flashing” but its bent up over a batten usually.


#4

Continuous flashings (“J” flashing) rely only on one small diverter at the outside edge to keep water from “hopping” over it. To name a few potential problems: should this diverter be overwhelmed by a heavy rain, get crushed by foot traffic, backward lapped or not be cut and nested properly onto the piece below it then all sorts of problems occur.

Step flashing is like Chinese insurance. If the river was rough, the ancient Chinese never put all the rice on one boat but rather put a little on every boat going down the river. In essence, the risk was evenly distributed. Step flashing takes the potential intruding rainwater and distributes it back to each course of shingles where it “bleeds” back out onto the shingle itself and reduces the water’s time on the flashing.

Just a flat out better way to do it.


#5

Tinner,

I believe step flashing should/must be used on the sidewalls of Chimneys. Of course, I believe these should ALWAYS be tarred to the brick. I think you still tar these step flashings right?

Also, have you ever ran into a chimney that didn’t have a cricket on the back side? What do you use here? I would be afraid to use step flashing on the back side of a chimney. I have seen entire neighborhoods with chimneys without crickets.

Last, does anyone use step flashing on the bottom side of a dormer? I hope not but I have torn off roofs several times where the continuous (roll) flashing is underneath the shingles below a dormer to my amazement.

I also agree with previous comment that properly installed step flashing(in the right location) will never leak. We can all agree that we have seen lots of improperly applied step.


#6

[quote=“famous”]Tinner,

I believe step flashing should/must be used on the sidewalls of Chimneys. Of course, I believe these should ALWAYS be tarred to the brick. I think you still tar these step flashings right?

Also, have you ever ran into a chimney that didn’t have a cricket on the back side? What do you use here? I would be afraid to use step flashing on the back side of a chimney. I have seen entire neighborhoods with chimneys without crickets.

Last, does anyone use step flashing on the bottom side of a dormer? I hope not but I have torn off roofs several times where the continuous (roll) flashing is underneath the shingles below a dormer to my amazement.

I also agree with previous comment that properly installed step flashing(in the right location) will never leak. We can all agree that we have seen lots of improperly applied step.[/quote]

W :shock: W really???

No tarring of step flash to the chimney, you nail those to the roof.

A chimney without a cricket gets a back pan flashing. A piece of metal 6" wider than the chimney (3" hang over each end), bend it 6" up the backside of the chimney and about 18" up the roof.

(bottom side of a dormer) Do you mean the where the front wall of the dormer meets the roof? If so you use a “front pan” or as we call it up here, Wall Flashing.
Goes over top all the shingles but under the siding.

So you step flash a sidewall of a chimney but you use Wall flashing on the sidewall of a house?
Talk about improper flashing.


#7

*Continuous flashings (“J” flashing) rely only on one small diverter at the outside edge to keep water from “hopping” over it. To name a few potential problems: should this diverter be overwhelmed by a heavy rain, get crushed by foot traffic, backward lapped or not be cut and nested properly onto the piece below it then all sorts of problems occur.

Step flashing is like Chinese insurance. If the river was rough, the ancient Chinese never put all the rice on one boat but rather put a little on every boat going down the river. In essence, the risk was evenly distributed. Step flashing takes the potential intruding rainwater and distributes it back to each course of shingles where it “bleeds” back out onto the shingle itself and reduces the water’s time on the flashing.

Just a flat out better way to do it.*

Pretty solid response there. Thing is though that I have seen both continuous and step flashings work… It’s a matter of using the best tool for the job. I will highly advocate the use of step flashing and believe it should be used whenever applicable but running/gang/continuous flashing has its uses also. Unless of course one of you pros would like to tell me how to step flash things like Spanish/Mexican tile, etc.


#8

A step will divert water onto the lower row and so on.A continuous flashing will get all the water from top to bottom,be overwhelmed by the amount of water and flow off the edge under the shingles.Where will that water go?On the roof deck,then we all know what happens.When re roofing a roof with a one piece flashing you must decide what to do with the F up.I used to sandwich the flashing with ice and water,cut the point off each shingle hope I got away with it.The last one I did that way leaked,so I deal with the siding and put steps in now ALLWAYS


#9

Step flashing a barrelled tile would require using a malleable product such as lead (or in the instance of a flat tile it would be a hard metal product more like step flashing).

Form it to the barrel clay tile with part of the “step” lead over the preceding lower tile and under the current upper tile. The “leg” of the step lead would go under the receiver strip (zee flashing on siding or stucco or under the counter flashing on hard masonry). I’ve done it before and it actually works better than a tile pan / gang flash set up (glorified “J” flashing). While it does work better, most customers don’t like the look of it.

Tile pan / gang flash with a bleeder sheet at the bottom is most common in the States. In Europe it is known as a “hidden gutter” and is not too common. The Euros mostly use the “step” lead applicaton.


#10

For a shingle roof there is no debate properly installed step flashings DONT LEAK.


#11

[quote=“keepitlow”]

Step flashing is like Chinese insurance. If the river was rough, the ancient Chinese never put all the rice on one boat but rather put a little on every boat going down the river. In essence, the risk was evenly distributed. Step flashing takes the potential intruding rainwater and distributes it back to each course of shingles where it “bleeds” back out onto the shingle itself and reduces the water’s time on the flashing.

Just a flat out better way to do it.[/quote]

yup well said. Running continuous flashing is a lazy way of doing things

[quote=“famous”]

This method also allows for flashing inspections before the shingles are applied. Permit inspectors in my parts are also requiring a 1 inch gap now from roof to siding. They want to see the shiny metal running along the wall and I have had framing contractors chastise me for painting flashing before the frame inspections are done.

I welcome intelligent debate and opinions…[/quote]

I always try to colour match all my metal with the shingles looks much cleaner. How to you paint the metal after the roof is installed with out making a huge mess


#12

A good roofer never “tars” his flashing Famous.The common practice in my area is to use a lead piece on the corners so you can qrap it nicley.


#13

Hi Famous,

When installing shingles, We typically install CertainTeed products. Our employees are taught how to shingle with the basis of the Master Shingle Applicators Manual. In this manual they do not recommend continous wall flashing. They do recommend step flashing. Get with the your local rep of whatever brand of shingles you install and they can tell you how they prefer their material to be installed. This way you have a process of procedure directly from the manufacturer on what they consider to be right. I am yet too see a shingle manufacturer that recommends the use of flashing cement on a shingled roof system. Like previously stated by Tinner unless it is required by a local building code or a group of “non roofers” flashing cement has no place on a shingled roof. If you step flash a chimney you could seal the top w/ urethane caulking or similiar prior to installing a counter flash. Do you use counter flashing?


#14

When I was in Florida the requirement was to seal each piece of step to the shingle then the shingle to the step.I was thrilled by that.I thought it was an invincible style of flashing installation.

I used that same technique when I came back to Missouri.I roofed about 30 houses in Missouri when I returned that winter.I got lazy and decided not to use that technique that spring.About a year and a half I started getting calls about leaks.

All 30 houses leaked at the walls.I am contributing those leaks to sealing the flashings.I am sure the cause was our harsh winters with ice and frigid temps.

Constriction and contraction.Missouri weather is silly.It could be -5* then 45* the next week.I am sure that after about 20 or so times of this during each winter took a toll on the sealant.The sealant I used was Wet/dri.I typically used Vulkem or Karnak.I purchased a mass quantity of this sealant at a great price.

I looked at each piece of flashing and shingle to see the seal area.The sealant was hardened but it was like charcoal.It crumbled and powdered with slight pressure.

I emailed the corporation and met with a rep from wet/dri.He took a sample of the sealant along with a copy of the initial contract as well as the receipt for purchase.To make a longer story short they reimbursed me for the product,the damages and all time and materials were paid for.It was determined as a product failure.I have never heard of such a thing before and only contacted them as an inquiry.I don’t use that product anymore and I don’t seal step in Missouri anymore either.

I feel each shingle having its own piece of step flashing offers far more protection and piece of mind than a continuous type.It has been said that the continuous can trap debris and back up.I agree with that 100%. If you think about it a continuous is like not cutting your tips from a laced closed valley.But who am I.? I have never had a leak at the wall using properly placed and nailed step flashing.The continous I have never tried but why would I when Ibelieve in the technique.


#15

Roofmaster,that scenario you talked about is interesting.The tar must of trapped water in
How many of you wrap ice /water shield up a wall if you can?I do if possible
We now always put at least a half roll of ice/water under the steps
Do you guys nail the step as you would a shingle ,or the lower corner of the step?
When I was taught to roof,doing new work, we nailed where you would a shingle.When I got into reroofing I was taught to nail the lower corner,looks better for the customer,the steps wont stick up.
Thats not the only rule that changes when comparing new/re roof style,that may be a another good topic


#16

NRCA steep slope roof system manual specs step flashing at all roof to side wall flashings. I encourage everyone to use one piece flashing so i have guaranteed repair work for years to come!! 8) p.s. no tar…ever.


#17

Thanks everyone for the excellent posts and inputs.

I always like to tar and mesh my step flashings around chimneys. I don’t like driving masonry nails out of fear of blowing out bricks. I just don’t trust glue or caulk to hold the steps in place. I always try to reuse the counter flashing that is installed in the mortar joints. I press it down into the tar bed of the step flashing and caulk/paint to match the shingle. I have done so many ice dam repairs this winter that I am also just putting Ice&Water shield around all Chimney crickets.

Good Advice. I am considering the prospect of clogging up the channel of the continuous flashing even though it is caulked.

It also seems like a near consensus that Ice & Water Shield is a good idea under step flashing?


#18

same here.

luckily, every roof that famous puts on with a continuous flashing, is in my market, and maybe someday, i’ll be getting calls to fix all of the leaky roofs.

Famous… have you ever actually been a ROOFER? I dont mean just someone who has sold roofs, and walked around on them with a tape measure. I mean packing shingles up ladders for a couple of years, ground cleanup, then moving on to tear off, maybe laying felt down… then after a few years of busting your ass, eventually learning how to shingle a roof?

because ive torn off shingles around here with ALL types of flashing. step flashing doesnt leak when installed properly. period.

oh, and you asking about putting step flashing where chimney pans, and at the base of dormers/etc are… is silly. nobody in their right mind would ever do that.

do you know the names, different purposes, reasons behind design, and proper installation techniques of the different types of flashing?

TAR on flashing? Why would you even have TAR on a freakin steep slope roof with shingles? REALLY? bro, you need to get your crew some good tin snips, a cutting wheel and have someone show them how to cut into rock, mortar, and install the counter flashing properly. you do know there are two parts to a chimney flashing, right? if things are flashed PROPERLY, all you need is metal, and nails. anything else is a band-aid for poor workmanship, or lack of knowledge on proper installation.


#19

[quote=“famous”]
I always like to tar and mesh my step flashings around chimneys.[/quote]

I think real roofing terminology would be a “Toke and Rag” A.k.a 3-course or if one is really motivated a 5-course.


#20

If the job calls for I&W then yeah. But if it’s only getting paper, then I run paper up.

Nail on the upper outside corner of the step, on the roof. It’ll be as far away from water as you can get.