Coal Tar vs. Asphalt Emulsion

Discussion in 'Seal Coating Forum' started by guster98, Jun 22, 2010.

  1. guster98

    guster98 LawnSite Member
    Messages: 4

    I've spent a lot of time trying to weigh the pros and cons of the two methods of driveway sealcoating (as a consumer). From what I've read it sounds like the advantages of each of the methods can be summed up as follows:

    Coal Tar
    1. Lasts longer
    2. Protects better (against oil and gasoline leaks)
    3. Fills small cracks better (protects better against freeze/thaw cycle)

    Asphalt Emulsion
    1. Looks better (even, less-streaky application)
    2. Easier and faster to apply (meaning labor is less expensive)
    3. Fewer fumes
    4. Possibly better for the environment

    What changes would you make to these lists?

    Can Coal Tar sealer be applied via spray? All of the local contractors I've spoken to want to apply asphalt emulsion sealer. I would prefer coal tar and am wondering if contractors can apply coal tar via spray.

    I'd appreciate any comments from people who know sealcoating.

  2. TriStar

    TriStar LawnSite Member
    Messages: 5

    We spray coal tar everyday.
  3. BIGBOY2008

    BIGBOY2008 LawnSite Member
    Messages: 146

    My only experience has been with coal tar sealers and i use a squeegee as opposed to spraying them. The first time i was around someone spraying coal tar emulsion i wasnt there but for fifteen minutes and had that bizarre tingling sensation all over my arms and neck. Im assuming it was the particulates in the air that was causing it.
    But the coal tar sealers will definitely burn you if you get it one you and it is in fact a very moderate chemical burn.
    And honestly if i had to spray the stuff and be up in it all day long and it tingled me to death like it did that one day i would switch to AE or find another line of work.

    But here is some info that will help you out:
  4. TriStar

    TriStar LawnSite Member
    Messages: 5

    He does make a valid point. All of our workers wear jump suits while spraying the sealer. It can and will cause chemical burn, I know personally because I have had minor burns from time to time. If you're careful with it and smart with how you apply it there are no issues.
  5. guster98

    guster98 LawnSite Member
    Messages: 4

    Thanks guys. BIGBOY2008, those links are among the best out there. I found that you have to be careful because just about all of the links I've found tend to be partial to one technology or the other. I had trouble finding a site that had an objective comparison. No "Consumer Reports" for this stuff. That's why I thought I'd ask for opinions from the people on this board.

    On the internet, the Asphalt Emulsion guys say their product penetrates, rejuvenates, and replaces elements lost over time, and coal tar is like paint that gets slathered on to cover-up asphalt.

    The Coal Tar guys say their product was developed for airport use, protects the asphalt against gas and oil, fills cracks and stays black longer. They imply that AE is inferior in almost every way.

    Thanks for the info. I know coal tar has a strong odor, so I can imagine that the chemicals it gives off can affect people while it's drying.
  6. guster98

    guster98 LawnSite Member
    Messages: 4

    While discussing sealcoating the driveway, I had an AE contractor draw the analogy of sealing a deck. He told me that using coal tar on the driveway would be like painting a deck. People stain their decks because stain penetrates the wood, and people should use AE on their driveway because it penetrates the surface. I said OK, but if I need to seal my wood trim, I'm going to paint it because I know paint is durable and will last many years. If I stained my trim, I'd have to be out there every year to do it over again.

    He said that's the reason people use PVC instead of wood trim these days. That was like telling me I should have put in a concrete driveway :confused:.

    He said he didn't understand why I thought coal tar was better, because it wouldn't look as pretty and shiny as AE. I said that from what I've read, it lasted longer and provided better protection. He seemed not to understand why those characteristics were important to me.
  7. BIGBOY2008

    BIGBOY2008 LawnSite Member
    Messages: 146

    From what i understand raw bulk asphalt material has an excessive amount of oils in it prior to the paving contractor laying it down in order to roll it out into a finished paved surface. The purpose of the excessive amount of oil is so the individual materials comprising the asphalt material can slide against each other in order to be compressed together to form the newly paved surface.

    The oils that are present within the pavement are what preserves it and causes it to have the common function and physical properties that all pavements in general should have.

    Once the new pavement is laid those excess oils will both leach out and be drawn out of the pavement via the heat and UV rays of the sun. But however after the excess oils are liberated from the pavement you want "x-amount" of what would be the remaining oil to be present and serving a particular purpose for being present in the pavement.
    That particular purpose is to allow the individual materials comprising the pavement to remain glued or locked together so the pavment will remain flexible as opposed to becoming hard and brittle.

    Asphalt sealer locks these oils into the pavement and prevents them from escaping. It is also a sun block that prevents UV rays from drawing the oils out of the pavement. It is a petro-chemical barrier that prevents oils and gasoline from making contact with the surface of the pavement and dissolving it.
  8. Mdirrigation

    Mdirrigation LawnSite Gold Member
    Messages: 3,583

    Guster you are about an hour from me , first asphalt emulsion is a west coast product , not readily avaliable in Maryland . the word "emulsion" means that it is a water based product , these dont rejuvinate , or penetrate asphalt , emulsions either asphalt or coal tar are true sealers . What sombody is trying to sell you is the oil based product . You can spray coal tar , we brush driveways , it last longer and no overspray . Go with the coal tar
  9. BIGBOY2008

    BIGBOY2008 LawnSite Member
    Messages: 146

    One thing you will need to remember is there are true asphalt sealers and then there are products that are known as asphalt rejuvenators.

    As you will know an asphalt sealer seals asphalt not allowing the oils to escape and not allowing other chemicals to be asborbed into the pavement.

    A pavement rejuvenator attempts to introduce chemicals back into the pavement to replace those that were lost through lenghty exposure to UV rays.

    One thing you should remember is contrary to popular belief there is no such thing as a "oil based pavement sealer". This is due the fact that if a product containing oil is applied to pavement the oil begin to soften and cause the pavement to deteriorate.
  10. JFGauvreau

    JFGauvreau LawnSite Bronze Member
    Messages: 1,298

    go with the coal tar, it is a much more natural jet black look in my opinion. As for applying it, yes it is a spray so there is a lot of mist and fumes, you just have to be carefully when you apply it, not to apply it on the interlock or white garage door. Always wear full protection clothing.

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