Spontaneous combustion

Discussion in 'Lawn Mowing' started by eruuska, Aug 7, 2006.

  1. eruuska

    eruuska LawnSite Senior Member
    Messages: 454

    I just finished about 11 hours of mowing (Saturday and today) a 3-acre lawn that has not been mowed yet this year. ( :cry: but payup ) I sucked all the clippings up with my TracVac and piled them up in the woods.

    Today as I started adding to the pile I stuck my hand deep down in the pile and it was HOT!

    What is the danger of spontaneous combustion in a grass pile? This house is generally unoccupied (second home) and I don't want the owner to show up and see a big pile of charred ruins.

  2. mjohnson1

    mjohnson1 LawnSite Member
    Messages: 76

    it's rather possible that's why farmers try to never bale wet hay and never put it in the barn wet. it can catch fire and burn the barn to the ground. not to mention it molds and can be bad for livestock. but yes it can definitely happen
  3. eruuska

    eruuska LawnSite Senior Member
    Messages: 454

    Yeah, I know it can happen, but is it something I need to lose sleep over?
  4. cborden

    cborden LawnSite Member
    from 46140
    Messages: 179

    When I was a trash truck mechanic, it was not uncommon to come in on Sunday night and find a residential rear loader smoldering. The drivers would not always dump on Friday afternoons and they would spontaneously combust after sitting in the sun all weekend.:blob2: :blob2: :blob2:
  5. mulcahy mowing

    mulcahy mowing LawnSite Senior Member
    from ma
    Messages: 721

    nothing to loose sleep over but I would spred that pile out next time i was there
  6. grass-scapes

    grass-scapes LawnSite Bronze Member
    Messages: 1,552

    The local Agricultural college here has had two barn fires this year, both started from hay in the barn. The first time they lost their large barn....the second, badly damaged their auxilliary storage barn.
  7. MOW ED

    MOW ED LawnSite Fanatic
    Messages: 5,028

    Have you ever been to the compost center in your community? They pile tons of grass in 20 foot mountains and it doesn't catch fire. Any organic material like grass will decompose when the conditions are right. Hay is a different animal than grass. The grass is tightly packed and it will generate heat but will not support open combustion. By its size, hay is more open and has potential for more air flow and the cause of those fires is usually because the heat of decomposition is allowed to build and not vent adequately because it is contained in a building.
    Thousands of plastic composting buckets are in use thru out the country and I know of no recalls because of fires.
    The grass is doing what it is supposed to do and as long as its out in the open it is not much of a threat. Visit this link to learn a little more. Its great that you are aware of fire potential but you can rest easier on this one.

  8. Daner

    Daner LawnSite Bronze Member
    Messages: 1,307

    Fires are a thing that keeps me concered all the time...Hay Is A grass...and they both will react in simumlar ways...There Is a microscopical action takes place...when the moisture content is over 20%...If you have say as high as 45%...for shure grass will heat...It can reach temps 700 Degres...and they will for shure fire up on you...If they reach that temp...It will normally ignite when you stir it adding oxygen.
  9. Nature-Ally

    Nature-Ally LawnSite Member
    Messages: 3

    I agree with Mow Ed. In fact, I believe that the temperature inside of a compost pile can get at high as around 140 degrees F. The high water content intitally and the tight compaction of grass prevents fires, but as he mentioned, hay doesn't compact as much and can allow a greater air flow increasing the chances for combustion. I have a compost pile in my backyard and I know that when I pop open the top, sometimes it is really warm. The microbes that are breaking down the plant material are really working then.
  10. LwnmwrMan22

    LwnmwrMan22 LawnSite Platinum Member
    Messages: 4,373

    Again, like Mow Ed said, grass is not hay.

    Yes, hay is a grass type plant, but it's not GRASS.

    It's like raking a bunch of dry leaves in a hugh pile on top of the fire. WHOOMP! They burn up.

    Now, take a huge pile of leaves that have collected in the gutter of the street for 2 years, all packed together, than have gotten 4" of rain on, after the snow.

    Put those on the fire. What happens??? Nothing, just steam.

    If you have a large load of grass in the back of your truck after bagging, especially in the spring, leave it in there over the weekend. It'll be very warm and steam like mad, but it's not going to burn.

Share This Page