From what I have seen chimney flashing is the most neglected area of a roof, if re-flashed at all. That is why this is such and important detail that you need to be aware of. More times than not it wasn't re-flashed during the last re-roof, which is against minimum Building Code. Here in Oregon they recently changed Building Code to indlude a cricket when ever reroofing is done, yet it is still rarely added to the job, since most homeowners do not know of this change to the code. Now you know.

Why a 2-Part Flashing is Needed with any Brick Chimney:
Chimney flashing needs a 2-piece; a step-flashing mounted on the roof deck integrated with the shingles, and a separate counter-flashing piece that is mortared into the gap between the bricks. NEVER cut into the brick! This 2-part system to allow for the movement of clay structure of the chimney and the wood structure surrounding it, caused by expansion and contraction as temperatures change throughout the day, and throughout the seasons from below zero to possibly 120 degrees. Also, as you heat up the chimney while in use.

The step-flashing gets nailed on the roof and lays up against the side of the chimney. Then the counter-flashing is mortared in the chimney (NEVER caulked) to hang down over the step-flashing to maintain a water tight seal, yet allow for this movement. This is why caulking this flashing is futile and will separate before long. If it is flashed properly, there should be no need to caulk it at all. Even in the corners. It needs to maintain this seal even with wind-driven rain and snow.

If you see black tar smeared on your roof, that is only a desperate temporary fix at best, and needs to be remedied quickly with proper rust-free flashing.

Common Problems With Roof Flashing:
Clearly the #1 cause of roof failure is faulty and or rusted out steel flashing; either from improperly installed, or complete lack there of, which I have seen all too often. If there is caulk on your roof that's usually a sign of a temporary leak repair and needs properly dealt with as soon as possible!

In my 3 decades of experience crawling up on several thousand roofs, seeing these details up close, I've seen how in most cases the Roofing Contractors did not re-flash many of these problem areas, which they were hired to fix in the first place. Let alone flashed the right way. Leaving the worse problem areas of your roof not resolved, so you've just been cheated out of thousands of dollars and made to suffer continuing stress. That's like having your car repainted without even washing your car first, or neglecting to sand the rusty areas for the paint to stick to a good clean solid surface. Resulting in the paint starting to peal off the first time you run it through the Car Wash.

I've done several tear-offs where I removed 2 layers of composite shingles over the bottom layer of wood shakes; in where the only flashing I found around the dormer was under the wood shakes, and of course it was very rusty and deteriorated. That means the last 2 Roofers had not bother to re-flash their dormer at all. I have yet to see evidence of a decent Roofer in this area (no joke). It really is that bad!

This means you are 99% at risk of being ripped off by any Roofing Contractor you're likely to encounter, so I have added this educational information to help arm you while interviewing potential Roofers. Since I do not sell roofing work, this infor is honest and unbias.

One of the problems stem from sheer ignorance, ethics, and lack of good examples to follow. Roofers come more from a hammer and nail Framer mind-set. Not from a sheet metal worker's perspective like me, so these areas of roofing escapes their private logic and confound them on how to manage wind driven rain, which all roofs will encounter.

Sadly ethical responsibility seems to be a thing of the past. I understand this is not just a local issue either. Improper roof flashing using just cheap steel is the standard across the Nation. This thin steel flashing will not even last as long as the most inexpensive low life-span 25 year shingles. Even if it does not rust all the way through it will cause unsightly rust stains down the roof, as seen in these photos.

To see more photos of this project click the link below
http://copper-by-design.com/rf/Viges.htm

I have personally seen thousands of examples of this close-up. In most cases they will just bend the old counter-flashing out and slip the new step-flashing under it, and then just bend that rusty counter-flashing back down over it. When I've gone out of my way to question Roofers about this they say it is the job of a Mason to replace that flashing. This might be OK if a Mason was called out to do it. Or, at least make sure the Homeowners was made aware this roof job is not yet finished, and they need to call in a Mason to finish their work. I have come to learn most Masons do not know how to replace this flashing either, and really don't want to be bothered with it. It's way too much work and not worth their time to even bid such a small and dangerous job, so you as the Homeowner are left with no options. How does this make any sense?

 Even if this flashing is not rusty at all, it is not going to last through the life-span of the new roof. Even though Roofers are not willing to replace old flashing they are not likely to bother notifying you the Homeowner of these rust issues that still need fixed, so you don't have a clue that the roofing job was never finished. Then you'll start to notice staining inside from those leaks, which means serious damage has already occurred.

What's worse with this scenario is how many Homeowners are conned into paying to fully re-roofing their house because of these flashing leaks, instead of just replacing that flashing. These fancy talking Salesman are much more motivated to sell a whole re-roofing package to unsuspecting Homeowners to make that big ticket sale. All the while, knowing they have no intention to replace that defective flashing with something better.

Even if they do actually replace that flashing, they again will do this new work without the benefit of using a rust-free metal like aluminum or copper. Keep in mind how in most cases they will not bother to re-flash the problem areas as they had promised; failing to solve your actual problems.

This is the main reasons liability insurance for Roofers has been very hard to get and extremely costly for several decades. Costing around 500% more than any other type of construction work. That is very telling in of itself; demonstrating irrefutable proof of what I'm saying here. Numbers don't lie. Feel free to research this.

Most of roof flashing can be replaced without re-roofing the whole house (as seen above), but of course that is far less profitable for a Roofing Contractor, so that option is rarely discussed or considered as an option.  Each one of those Roofers know better, but they still do the same kind of crapy roofing work with that same cheap steel flashing, which they just tore off of your house. Seeing the evidence of it's failure time and time again.

They all know how the new flashing will fail in short order, but they just don't care. Isn't this said to be the definition of insanity: doing the same thing and expecting different results. Sadder yet is how they are only saving not more than $300 on the average reroofing by not using all aluminum flashing; which is about twice as thick and will not rust even if all the paint were to flake off decades later and still protect your house.

It's criminal in my mind. Can you imagine the amount of landfill that could be reduced if steel flashing was made illegal? Yet for over 30 years that I know of; Roofing Suppliers are not allowed to stock aluminum, stainless steel, or copper flashing by their Corporate Office.

If that were not bad enough; Instead of flashing areas with metal; they will often use the cheapest caulking sold; called mastic or asphalt tar. They just smear it around those problem areas. Mastic is just fibered tar with no UV protection. This will usually get the roof past their minimum required 1 year warranty the Construction Contractors Boards requires of any Licensed Contractor, but not lasting much more than that. Mastic will become brittle, crack, and peal away within a few years. If their work were to be inspected by a State Code Enforcement Inspector it would not be approved. They are not to use mastic anywhere on a roof. That is a clear sign this roof was not properly flashed right. Mastic is only to be used as an emergency patch to pacify the leak until a proper fix can be made. Although, it makes for a very messy clean-up when that repair can be done. The roofing in that area has to be replace after a mastic attack, as seen in these photos:

To see more photos of aluminum flashing click the link below
http://copper-by-design.com/rf/Alum.htm

We know this to be a very common intentional crime of Roofing Contractors, since pretty much any roofer has seen the evidence of these all too common issues when doing a tear-off of an old roof; i.e. very rusty steel flashing on the roof and mastic failure with stained plywood underneath.  When they tear into a bad roof for replacement it tells a story: why this roof failed.  They would have to be complete morons to not see this clear evidence in front of their eyes.

Yet, they continue to ignore this evidence and do the same shoddy work, since in most cases they are not required to file for a building permit to replace your roof year after year; not having to worry about an inspector double checking their work. It has been this way for over 3 decades that I know of. If more than 15% of the roof deck needs replaced a Roofer is required to file for a permit. Yet that is still rarely done, since they know their work will not withstand the scrutiny of an inspection and you are the victim of this negligence.

What about Lead Flashing?
Some clients have asked about using lead for chimney flashing. Roofers like it, since they can cut is so easily with a box-cutter and form it by hand. It is some times use while the chimney is being first built, but I do not know how you could be able to get it into the mortar, when the more rigid and thinner copper flashing is difficult to quickly install before the mortar sets.

Another important issue with lead is how soft it is. I have seen numerous cases where animals had chewed holes in lead flashing.

My understanding is lead is harmful to the environment and people as well, so lead is ill advised. That is why they made lead illegal to use in gasoline almost 50 years ago.

Common signs of shoddy workmanship:
The most common mistake I see Roofers make when they have bothered to re-flash a chimney is to cut a shallow groove along the diagonal sides of the chimney to caulk a straight piece of flashing in, but these will not remain attached for long to the crumbly bricks and old mortar. Although that is not the worst problem; this sets up a fracture point for the chimney to crack and possible collapse in a minor Earth tremor. I have seen lots of evidence of this happening. So, keep in mind how if they do this to your chimney, they have permanently damaged your chimney. Where the only solution would be to rebuild the chimney down to the roof line with new bricks. If this damage has not yet been done to your chimney you need to warn your Roofer how you will require them to rebuild your chimney if they do this.

Shown in these photos below I was able to easily pull the long side flashing piece off without straining. Let alone the need for tools to pry it off. That is an example of how poor this sort of fix is. This was not an old install either. It was done less than 2 years prior to my replacement work.

To see 12 more photos of this project click the link below
http://copper-by-design.com/rf/Bassett.htm

Even high quality silicone caulk should never be used to attach counter-flashing, because it is just rubbery and adds no structural strength to your compromised chimney. Just as with the useless effort of tuck-pointing a chimney to make the mortar grooves look nice again; the new granulated caulk in such a shallow groove has only the old crumbling mortar to stick to, so it will simply fall out within a few years. These grooves need to be ground out a lot deeper than just 1/2" in order to have the upper and lower brick surface to adhere to, and only be filled back in with REAL mortar.  The groove needs to be at least 1.5" to 2" deep.  Anything short of that is a waste of time and money.

Aluminum flashing can be special ordered from a fabrication shop like mine, but of course that makes it just much more expensive than mass produced stock, but the time delay is the main reason roofers will not have it made for your house. If you bothered to have aluminum flashing listed int he contract, 9 times out of 10 they will still show up with steel flashing parts. If you are not there with a magnet to test and demand they get the right flshing, you just got screwed!

My Roofing web page at: http://dmr-gutters.com/rf/roofs.htm goes into more detail about these terrible issue.  So don't leave without reading it over. It will help to save yourself a great deal of wasted cost and anguish down the road.

Can you make us a custom copper chimney flashing kit?

Here is an example of one of my first Client installed chimney flashing kits back in 2008:

I seem to be the only sheet metal shop willing to spend the time to work with Homeowners through e-mail to figure out these custom kits for them or their local installer to use. They are labeled and numbered in order of installation, precut, and bent to minimize customization needed at the job site. Below is some instruction and detailed photos to help give you a good idea of how to do this properly.

For more information regarding custom chimney flashing kits I make for our Clients across the Nation go to my Flashing Kits web page for more details:

http://copper-by-design.com/rf/cf-kits.htm

What about chimney flue pipe flange and other flashing?
As you can see from our web site I can also help with many other custom flashing needs. Although, you may need to consider physical contact of the copper flashing with steel pipes and the detrimental effect it will have on the steel through electrolysis or galvanic corrosion. The steel will not harm the copper, but the copper will accelerate the deterioration of the steel. Stainless steel is compatible with copper. This chimney pipe for a wood stove in my wood shop corroded within a year and became unusable.

What If I Already Have This Kind Of Shoddy Workmanship On My House?
If you are are a victim of this all too common unethical business practice you can show your Contractor this web site. Then you should be able to deduct the cost of repairing your chimney and it's flashing even if you are going to do it yourself, plus the cost of cleaning off that black tar. I would encourage you to insist he has that tar removed and cleaned off by his workers to the point as if it were never there. That ought to teach him a lesson. It is messy work and solvents on your new roofing will damage the shingles and cause a terrible staining mess. If the contractor uses a solvent he'll then need to replace all the damaged and stained shingles at the same time.

Do not let them talk you into any other alternative, trying to minimize their costs. They will try to discredit me and say I do not know what I am talking about, but it is simple logic here they cannot BS their way out of if you stand your ground. Roofers will claim that it can only be done this way when the chimney was first built by the brick mason, but I prove here that is simply not true.

Below are examples of jobs I've worked on, that show these shoddy practices I've worked to repair.

Are there any other flashing shapes that may be better?
In my effort to seek a better product for my clients I had designed a special type of step-flashing with a pair of 45 degree bends, in stead of just a single 90 degree bend. This is an improvement over the standard right angle bend configuration normally used. This has several advantages and should not be difficult to fit into any type of roofing material.

Here are a pair of photos of this alternative flashing being installed by one of our clients:

Sealing around the corners of a chimney has always presented a problem to make sure it's water tight without the use of a caulk, which could fail sooner than the life span of the roof. It needs to maintain a seal even in the harshest wind storms and allow for the expansion and contraction with will differ than the wood structure. I have found this alternative shape helps in several other ways as well:

(a) navigates the rain water out away from the corners of the chimney a bit better.

(b) slows the water down and reduces upward splattering under the counter flashing.

(c) helps to be able to trim off the commonly compromised and damaged shingles nearest the chimney when replacing the flashing without a full re-roofing project, thus reducing the shingles needing replaced around the chimney.

(d) helps reduce scraping needed where the chimney meets the roof: old caulk or sloppy mortar work.

(e) makes it easier to cut the new grooves without needing to grind so close the the roof.

(f) application of an underlayment resting up against the side of the chimney for added protection is also made possible; without such risk of cracking that membrane needed with conventional flashing with such a sharp bend profile.

To see more photos of this installation follow this link:
http://copper-by-design.com/rf/Druschel.htm

Let me know if you need any special configuration and we'll customize your kit to fit.