# How to get roofing tar off of skylight



## Gymschu (Dec 12, 2010)

Next to impossible this time of year. What a gooey mess you will make. If you wait until cooler weather, (when the tar hardens up) it may just scrape off with a razor scraper.


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## Windows on Wash (Aug 30, 2011)

Silicone spray as well.


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## begal (Jul 23, 2014)

I guess paint thinner will damage it? What if diluted it?



LoE3 Neat glass provides 61% visible light transmission.
The titanium dioxide layer of Neat glass reacts chemically with the sun’s UV rays and causes organic materials that are on the glass to decompose.


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## ratherbefishin' (Jun 16, 2007)




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## Davejss (May 14, 2012)

I've been roofing half my life and never used tar. Proper technique should eliminate the need for that crap. But since it's there you might try gasoline.


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## begal (Jul 23, 2014)

Davejss said:


> I've been roofing half my life and never used tar. Proper technique should eliminate the need for that crap. But since it's there you might try gasoline.


Really how do you install a skylight without roof tar? When you say crap is that opposed to the natural goodness that roof shingles are made of?


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## roofermann (Nov 18, 2013)

begal said:


> Really how do you install a skylight without roof tar? When you say crap is that opposed to the natural goodness that roof shingles are made of?


With either a manufacturer supplied or site made flashing kit. Tar is ancient technology.


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## begal (Jul 23, 2014)

Same chemicals used in your shingles. So why wouldn't you use tar? What do you fill the holes from your brackets with?


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## roofermann (Nov 18, 2013)

begal said:


> Same chemicals used in your shingles. So why wouldn't you use tar? What do you fill the holes from your brackets with?


Flashing covers the brackets. Tar fails sooner than the roofing material.


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## Bob Sanders (Nov 10, 2013)

Davejss said:


> I've been roofing half my life and never used tar. Proper technique should eliminate the need for that crap. But since it's there you might try gasoline.


I see tar used all the time on skylights in flat top roofs.


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## begal (Jul 23, 2014)

Roanoke, VA, USA. If you drive 750 miles north you will come to my house. You have no clue about roofing in a winter climate. When the snow and ice melts the water will enter the flashing. That is obvious.


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## jagans (Oct 21, 2012)

Since this is a roofing forum. it would be really nice if at least the professionals here would use the correct terminology. I do not mean to be a wise axe but "Tar" in the world of roofing refers to the bitumen derivative achieved by the destructive distillation of coal. In other words, Coal Tar. 

You are more than probably referring to an Asphalt product, either flashing cement, or roofing cement, which are both petroleum derivatives which results from the distillation of crude oil.

There, now as far as the original question goes, are you sure your light is glass? Most are plastic, usually Polycarbonate. I would clean it with WD-40, and then 90% Isopropyl alcohol.

A properly ventilated roof assembly on a steep roof does not require flashing cement if done properly. If you are experiencing hydrostatic pressure from melt water at a penetration your roof is not properly ventilated.


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## BigJim (Sep 2, 2008)

begal said:


> Roanoke, VA, USA. If you drive 750 miles north you will come to my house. You have no clue about roofing in a winter climate. When the snow and ice melts the water will enter the flashing. That is obvious.


Vancouver BC is a little further than that. LOL


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## noquacks (Jun 5, 2010)

begal said:


> I guess paint thinner will damage it? What if diluted it?
> 
> 
> 
> ...


paint thinner can never damage glasss.


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## noquacks (Jun 5, 2010)

jagans said:


> Since this is a roofing forum. it would be really nice if at least the professionals here would use the correct terminology. I do not mean to be a wise axe but "Tar" in the world of roofing refers to the bitumen derivative achieved by the destructive distillation of coal. In other words, Coal Tar.
> 
> You are more than probably referring to an Asphalt product, either flashing cement, or roofing cement, which are both petroleum derivatives which results from the distillation of crude oil.
> 
> There, now as far as the original question goes, are you sure your light is glass? Most are plastic, usually Polycarbonate. I would clean it with WD-40, and then 90% Isopropyl alcohol.


good info/clarification, jag. Oh- I took it his skylight was really glass, not plastic, or other......


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## Bob Sanders (Nov 10, 2013)

BigJim said:


> Vancouver BC is a little further than that. LOL


I live in Winnipeg. We were officially colder than Mars last Winter and that's not abnormal. Again, I see lots of tar being used on flat tops with sky lights.

True, it is an older technology, but it is not down and out.


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## Bob Sanders (Nov 10, 2013)

noquacks said:


> good info/clarification, jag. Oh- I took it his skylight was really glass, not plastic, or other......


Normal paint thinner works on plastics with no damage. It's the acetone or deet based stuff that will eat plastic.


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## 95PGTTech (Jun 24, 2014)

Bob Sanders said:


> I see tar used all the time on skylights in flat top roofs.


I have no dog in this fight, but this is the absolute worst justification for an opinion in this thread. I've been working on cars professionally for 15 years now and I've seen some stuff that would make your blood boil, installed both DIY and professionally. Yesterday had a customer-installed packing tape flex joint pre-cat. That wouldn't even make my Top 10 list for the year.


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## jagans (Oct 21, 2012)

Bob Sanders said:


> I live in Winnipeg. We were officially colder than Mars last Winter and that's not abnormal. Again, I see lots of tar being used on flat tops with sky lights.
> 
> True, it is an older technology, but it is not down and out.


Low slope (what you are calling flat) are WATER PROOFING, and must therefore be able to withstand hydrostatic pressure. Steep roofs (3/12+) are WATER SHEDDING roofs. They are a whole different animal, and it is the foremost reason that steep roofers often fail miserably when they try to enter the world of low slope roofing.

If you saw flashing cement at the plane of the roof, the skylight was probably not flashed properly to begin with, or it was what is referred to as a self flashing curb, which IMHO is hogwash.


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## Windows on Wash (Aug 30, 2011)

Looks like I missed all the fun. This thread is getting juicy.


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## Bob Sanders (Nov 10, 2013)

jagans said:


> Low slope (what you are calling flat) are WATER PROOFING, and must therefore be able to withstand hydrostatic pressure. Steep roofs (3/12+) are WATER SHEDDING roofs. They are a whole different animal, and it is the foremost reason that steep roofers often fail miserably when they try to enter the world of low slope roofing.
> 
> If you saw flashing cement at the plane of the roof, the skylight was probably not flashed properly to begin with, or it was what is referred to as a self flashing curb, which IMHO is hogwash.


So I guess long story short... you're agreeing with me. You still see tar being used in the roofing industry.


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## roofermann (Nov 18, 2013)

Bob Sanders said:


> I see tar used all the time on skylights in flat top roofs.


On BUR flat roofs, yeah. Not on sloped.:thumbsup:


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## hotrod351 (Jun 15, 2012)

WD40. have used it for many many years. works perfect and doesnt hurt anything.


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## Windows on Wash (Aug 30, 2011)

hotrod351 said:


> WD40. have used it for many many years. works perfect and doesnt hurt anything.


+1

I like the silicone but 1 in the same.


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## jagans (Oct 21, 2012)

Bob Sanders said:


> So I guess long story short... you're agreeing with me. You still see tar being used in the roofing industry.


No, I am not agreeing with you. Roofing cement, and flashing cement are asphalt based products that are used in some cases on low sloped roofs. If your roof is steep, (3/12 +) you should not need flashing cement, as a skylight used with a steep roof such as asphalt shingles should have individual base tins, often referred to as step flashing, head flashing, and apron flashing, and it should have a proper counter flashing. In a properly installed water shedding roof, water is always redirected out onto the surface of the roof, therefore cement or sealant is not needed, and in many cases it actually causes leaks by inhibiting the free flow of water from the system.


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## OldNBroken (Jun 11, 2008)

I'm late too. Not that I care to respond to the OP, but you are all wrong. Citrus cleaner will clean asphalt-based products off most anything without damage. 

What would y'all do without me! :thumbup: :thumbup: :thumbup:

Anyone else get a lovely nasty-gram from the OP earlier? Or am I just special?


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## Davejss (May 14, 2012)

begal said:


> Really how do you install a skylight without roof tar? When you say crap is that opposed to the natural goodness that roof shingles are made of?


Proper flashing and counter flashing technique. Roof shingles are made of several components engineered to be just what they are. Roofing tar has it's place. Like wind sealing under rake shingles for instance. But to rely on tar to seal skylight caps is simply putting off your eventual leaks.
But to each his own. I don't use it and my roofs don't leak.


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