oil system staining roof shingles (not soot)

Robert B

I have a costomer that has a valiant boiler With riello burner and was getting stained roof shingles ( beige to a rust type color) around his 30 foot metalbestos chimney. It was serviced previously by his oil co. He had a soot-up, so they cleaned it,and gave the burner more air (lower co2).I was called in and noticed they could never get higher then 10% co2 without smoke. After multi visits with riello and other consultants we changed the burner to a beckett af2 and my combustion parammeters were perfect. We brought in fresh air to the burner, he replaced his shingles, and now 3 months later the new asphalt is staining. The orginal system didn't call for a draft damper, but I had excessive draft so I added one. We had the chimney inspected and swept. The attic/roof was found to be very hot (a/c complaint) so I added a attic ventilator close to chimney. Anybody have any input???

Steve Ebels

What you're seeing there

Has nothing to do with the boiler or oil. Most likely it is the reaction of the galvanizing leaching off from the flashing when it rains. As you drive down the street, notice the roofs with an outside antenna mounted on them. Invariably (if the shingle color is light) you will see the same stripping running down the roof from the galvanized legs of the antenna tripod. About all you can do is replace the flashing with a stainless one or aluminum. I've seen it dozens of times, always where something galvanized penetrates or is mounted on the roof.

Steve Eayrs

Have seen a lot of the same...

> I have a costomer that has a valiant boiler With

> riello burner and was getting stained roof

> shingles ( beige to a rust type color) around his

> 30 foot metalbestos chimney. It was serviced

> previously by his oil co. He had a soot-up, so

> they cleaned it,and gave the burner more air

> (lower co2).I was called in and noticed they

> could never get higher then 10% co2 without

> smoke. After multi visits with riello and other

> consultants we changed the burner to a beckett

> af2 and my combustion parammeters were perfect.

> We brought in fresh air to the burner, he

> replaced his shingles, and now 3 months later the

> new asphalt is staining. The orginal system

> didn't call for a draft damper, but I had

> excessive draft so I added one. We had the

> chimney inspected and swept. The attic/roof was

> found to be very hot (a/c complaint) so I added a

> attic ventilator close to chimney. Anybody have

> any input???



and I believe it has a lot to do with cool flue gas temp., which are way too close, or below 300 deg., and condesate and drip down the stack and flashing. I bet you will notice that not only the flashing, but your stainless stack it stained. It just shows up a lot more on the galv. flashing.

Its a problem in our area with higher efficient boilers in our area, but you will never see it a problem with the old fuel consuming beast.

Also was wondering why you had a problem with the Reillo. I would bet the problem was not the burner itself, but maybe the depth the burner tube was inserted in the combustion chamber? , or was the fuel pressure pump OK?
I have had real good results with Reillo.

Steve

Steve Eayrs

Flue stains

> I have a costomer that has a valiant boiler With

> riello burner and was getting stained roof

> shingles ( beige to a rust type color) around his

> 30 foot metalbestos chimney. It was serviced

> previously by his oil co. He had a soot-up, so

> they cleaned it,and gave the burner more air

> (lower co2).I was called in and noticed they

> could never get higher then 10% co2 without

> smoke. After multi visits with riello and other

> consultants we changed the burner to a beckett

> af2 and my combustion parammeters were perfect.

> We brought in fresh air to the burner, he

> replaced his shingles, and now 3 months later the

> new asphalt is staining. The orginal system

> didn't call for a draft damper, but I had

> excessive draft so I added one. We had the

> chimney inspected and swept. The attic/roof was

> found to be very hot (a/c complaint) so I added a

> attic ventilator close to chimney. Anybody have

> any input???



I have a lot of problems with roof stains around here too, but believe its due to the low stack temp.'s. They get down around 300 deg. and you will have condesate once it hits the atmosphere. I bet if you look close the stain is not just on the galv. flashing, but also running down the stainless flue. Whats the present stack temp.?, CO2?
Did you say there is no barometric damper?

As far as Reillo, I have had great results with them. Can't imagine why it wouldn't work, but a Beckett would. Must have been a bad fuel pump? or burner tube not inserted into the combustion chamber enough, or too much? I've seen Reillo work in a slight neg. pressure, or in draft conditions, where most others wouldn't.

Steve

Steve Eayrs

Flue stains

I have a lot of problems with roof stains around here too, but believe its due to the low stack temp.'s. They get down around 300 deg. and you will have condesate once it hits the atmosphere. I bet if you look close the stain is not just on the galv. flashing, but also running down the stainless flue. Whats the present stack temp.?, CO2?
Did you say there is no barometric damper?

As far as Reillo, I have had great results with them. Can't imagine why it wouldn't work, but a Beckett would. Must have been a bad fuel pump? or burner tube not inserted into the combustion chamber enough, or too much? I've seen Reillo work in a slight neg. pressure, or in draft conditions, where most others wouldn't.

Steve

Joe Kuhl

oil system staining roof

I agree with you Steve. Kind of hard to tell fer sure from the pic. but the cap, sections of pipe and storm collar look pretty clean to me. No staining at all but that flashing doesn't look stainless steel. Any debris stuck behind it could be having a chemical reaction with the metal and causing that stain. I would have a sheel metal contractor check it out and possibly replace that flashing and have him make up a crickett for the back side to channel away anything collecting there.

Geno_15

Try

Changing the roof to match the color of the stain. Sorry, couldn't help myself. I don't see the stain on the stainless flue. I'd have to say it's the flashing, it looks cheap. Also, if the chimney is condensating you should have water coming out of the clean out tee at the bottom of the chimney. Check there to see. Good luck, you've inherited somebody elses problem.

Mike T., Swampeast MO

I've got to agree with Steve. I see stains that color on roofs all over town and oil is unheard of in this area.

Bob Boltz

Staining

It could be flue gases condensing. I have seen this before, try using a low sulfur fuel (500 PPm or less), should take care of the staining.

hot_rod

paint the roof jack!

I see that on gas and LP fired chimneys also. They make paint that will stick to galv.

In some "exclusive" subdivisons around here the jacks, and B vent, MUST be painted to match the shingles, usually cedar. It actually does look a lot nicer and prevents the cedars shingles from staining.

Maybe acid rain! Any coal fired plants nearby?

hot rod

Steve Ebels

Metal reactions

Can do wierd stuff. I have a length of #8 bare copper ground wire running along the ridge of my roof on the North side. Guess what? No moss growing where the wire is. A old timer told me to do this a long time ago and it's worked on every roof I ever tried it on.

Robert B

have to add the before picture

This pic is prior to the work I performed. When I installed the attic ventillator I noticed alot of little white particles along the top of chimney cap,and when the boiler fired off that bi-product of combustion would be emmitted onto the roof like a salt shaker. There again I'm thinking it's too much draft and something to do with the chemical composition of the shingles and the sulfuric acid in the white powderie residue of burning oil. Bear in mind that the boiler is set up perfect. No smoke, about 11.8% co2, 425 degrees. I added a draft damper because I was burying mt draft gauge, and after adding it I still have -.05 stack and -.03 over fire, with the damper wide open.