# Debri calculator for removing flat roof??



## peacefully777

We almost always do new construction rather than reroofing in regards to flat roofing, or low slope roofing. We're well versed on reroofing with asphalt shingles. However we are interested in getting into reroofing flat roofs. We are having difficulty calculating how much roofing will fit in a 20 yard dumpster. 

Meaning we need to know how many squares of 4" thick insulation and membrane can fit into a 20 yard dumpster.

If anyone's has any experience with this please let me know.


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## 1985gt

peacefully777 said:


> We almost always do new construction rather than reroofing in regards to flat roofing, or low slope roofing. We're well versed on reroofing with asphalt shingles. However we are interested in getting into reroofing flat roofs. We are having difficulty calculating how much roofing will fit in a 20 yard dumpster.
> 
> Meaning we need to know how many squares of 4" thick insulation and membrane can fit into a 20 yard dumpster.
> 
> If anyone's has any experience with this please let me know.


Not a lot.

Insulation is either 4x4 or 4x8. So either .16 or .32 square per board. 20 yard dumpster depending on who made it. 8' wide 20' long and 4' high. To stack full sheets in a dumpster you won't fit much. 

If the insulation comes off good say like on a ballast roof or even mechanically attached or fully adhered we stack in on a trailer.


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## JBL

I calculate by tons or amount of trash by square feet , I only used yards in concrete not in roof. If have 4" roof per square feet and weight about 11 pounds per foot . The container is abou 15 feet L and 5 w 8 high .But it can hold up to 10 tons "short way of do it" 8 'x12" =96". 96"÷4" = 24. 24 layers of 4" then 5'x 15' =75 square 75x24= 1800 squares takes a container 15 L, 5w, 8h . But it weights 11 pounds per squares feet 1800x11= 19800 pounds 19800÷2000= 9.9 tons . Hope it help you calculate trash volume and weight. That's is my short way of doing it.


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## Grumpy

If the roof is large enough there are companies that will pull up their dumps and let you dispose your insulation for free. 

I always used a calculation per sq ft. Where I work now they calculate by the ton. I don't like their formula because ISO weighs little but takes up alot of space.


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## JDD

When removing roof pea gravel consider 2400 lbs per yard. A yard of 2" or pea gravel on a flat roof would equal approx 240 squares


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