Tar streaking on roof shingles

General Lee · 04-08-05, 12:05

The back side of my roof on my house has alot of "tar runs" from the shingles. It really makes the roof look like crap. The condition of the roof is still in good condition, only 12 years old.

Question is, is it safe to pressure wash the roof. I'm guessing no- out of the possibilty of de-grading the outer layer of the shingles. I always see advertisements for roof and shingle cleaning and wondered if it is safe or worth it, and if it will actually come clean.

Anyone have any advice?

seracis · 04-08-05, 12:29

You can powerwash your shingles, but it does remove some "life" from them. But, powerwashing doesn't do all that well against tar. It may be worth a shot. Start with the lowest run first and see if it will work.

GearHead_1 · 04-08-05, 01:30

I'm assuming we are talking asphalt shingles here. I wouldn't think that putting a pressure washer on an asphalt shingle would be a good idea. What color are your shingles (light by chance)? Any chance that it's dirt and not tar? Unless the roofer has used some additional tar to seal the tabs I would think it's unusual to have it run out. Ventalation issues can cause the roofing material to overheat and delaminate. One other thought, most shingles have a 15, 20 or 30 year warranty any chance yours falls under one of these. If you are to pursue the warranty issue you need to make sure that your attic/roof is properly ventalated (ridge vent system, roof turtles or power fans). That's one of the first thing roofing manufacturers use to get out of covering a warranty.

General Lee · 04-08-05, 02:35

Gearhead- Yes, asphalt shingles. They are a Tan/beige color on the light side thats why the tar runs stand out. I've noticed alot of the house's in my neigborhood have the same problem. I'm gonna go out on a limb and say I have 15 yr shingles, probably your normal contractor grade cheapo's. I bought the house when it was about 7 yrs old. I have been told improper ventilation can cause this (a home inspector told me) I do have a ridge vent and attic vents on both ends of the house but no attic fan. I also have vents located in the House eaves. I wouldn't know who to get a hold of concerning the warranty on them unless you are talking about Home owners Insurance? I wonder if that a possibility?

Eliot Ness · 04-08-05, 05:19

What you think is tar might be dark mildew stains. I've seen that a lot, and our old house had them. I bought some special cleaner for it, applied with a garden sprayer, but it didn't do much for them. I next tried some good old Clorox (applied the same way) and it took most of the stains off (I rinsed with a hose). I can't remember if I diluted it with water or not, but it's worth a try.

GearHead_1 · 04-08-05, 05:24

That's kind of what I was going to suggest. Assuming the shingles are on the light side I would think that Clorox applied with a pressurized weed sprayer might be worth a try.

TW85 HHI · 04-08-05, 05:52

I do not think it is tar. I am willing to bet it is staining from trees and mildew. Very common problem and easily fixed using Clorox, a pressure sprayer (the one you pump by hand and then spray), and a garden hose. Do not use a pressure washer on shingles.

BTW, your ridge/soffit vents are fine. We have the same setup on our house without attic fans and assuming the soffit vents are not clogged, they provide adequate ventilation.

GearHead_1 · 04-08-05, 06:01

Quote:

Originally posted by TW85 HHI
BTW, your ridge/soffit vents are fine. We have the same setup on our house without attic fans and assuming the soffit vents are not clogged, they provide adequate ventilation.

I hope it didn't come across that I was suggesting that attic fans were the only answer to a heat problem. I listed several possible solutions and there are a couple of different types of fans both powered and non powered. Ultimately what determines which system you go with is how many cubic feet of attic you have to cool. Each system has it place and sometimes a combination of systems is necessary, ridge vent systems alone aren't the system of choice when it comes to large areas in hot climates. There are formulas (though I don't have one at hand) that will help determine how much air you have to move and which system is most appropriate.

Good luck with the shingles, I will be anxious to hear how it turns out.

TW85 HHI · 04-08-05, 06:06

I actually was not even responding to your post.

Agreed, some houses need a combination of vents and I'm sure our house would be more efficient with one or two fans but I really have a hard time wanting to put large holes in the roof decking considering we are hurricane prone.

Eliot Ness · 04-08-05, 06:06

Quote:

Originally posted by TW85 HHI
........Clorox, a pressure sprayer (the one you pump by hand and then spray), and a garden hose..........

Yep, that's the type of sprayer I used, not the garden type that hooks to a hose (I should have been more clear on that that).

GearHead_1 · 04-08-05, 06:11

Quote:

Originally posted by TW85 HHI
I actually was not even responding to your post. Agreed, some houses need a combination of vents and I'm sure our house would be more efficient with one or two fans but I really have a hard time wanting to put large holes in the roof decking considering we are hurricane prone.

I just thought that since I had brought it up, maybe the way I had worded it was giving someone the wrong impression.

General Lee · 04-08-05, 08:25

I'll give the Clorox a try. It may very well be mildew only. I don't have any trees near by and now that mildew was mentioned... I just cleaned the siding on the entire back of the house the other day due to mildew.

TW85 & Eloit- did you guys agitate w/ a soft brush or just spray clorox and rinse?

Thank you all for the advice, Hopefully some cleaning will do the trick, I really don't want to get a new roof just for this reason.