Math Help

busterb · 01-04-2006, 11:15 AM

on slopes not less than 1/4" per horizontal foot. How much drop would that be in 25 feet? Would it be 25 times .25? 6.25 inches? If so the roof someone is trying to sell me is not recommended by this web site Here

Beestie · 01-04-2006, 11:29 AM

Think of it as a 1" drop per four feet of run. For guesstimates, there are six "four-feet runs" in 25' so make it a six inch drop. For precision, add the 1/4" for the extra foot (25 - 6*4 = 1) for a precise answer of 6-1/4"

1/4" per foot is basically flat. That's also, as I recall, the minimum slope for drain pipes making it the bare minimum angle to encourage the flow of water.

I assume you are not using shingles since the min rise to run for shingles is 3:12 (3 inches per foot).

What is the roofing material?

xoxoxoBruce · 01-04-2006, 11:48 AM

They're looking for positive drainage which they define as

Quote:

Positive Drainage: The drainage condition of a roof where all water is gone from the roof surface within forty-eight hours of precipitation during normal drying conditions.

So no low spots for puddles are allowed.
At least Modified Bitumen would be melted down and form a continuous cover unlike shingles which have to have more slope.

busterb · 01-04-2006, 12:14 PM

Looks like the answer is 25 times .25 for 61/4 or 6.25. What is the roofing material?
It's in link above thanks.

xoxoxoBruce · 01-04-2006, 03:56 PM

They're showing 3 different materials in that link, Buster.

Beestie · 01-04-2006, 06:06 PM

Quote:

Originally Posted by xoxoxoBruce

They're showing 3 different materials in that link, Buster.

Nor does it explain why what he is being "sold" falls short of what is being recommended. I'll see your

and raise you one

01-04-2006, 11:15 AM	#1
busterb NSABFD Join Date: Jul 2004 Location: MS. usa Posts: 3,908	Math Help on slopes not less than 1/4" per horizontal foot. How much drop would that be in 25 feet? Would it be 25 times .25? 6.25 inches? If so the roof someone is trying to sell me is not recommended by this web site Here __________________ I've haven't left very deep footprints in the sands of time. But, boy I've left a bunch.

01-04-2006, 11:29 AM	#2
Beestie -◊\|≡·∙■·∙≡\|◊- Join Date: Feb 2003 Location: Parts unknown. Posts: 4,081	Think of it as a 1" drop per four feet of run. For guesstimates, there are six "four-feet runs" in 25' so make it a six inch drop. For precision, add the 1/4" for the extra foot (25 - 6*4 = 1) for a precise answer of 6-1/4" 1/4" per foot is basically flat. That's also, as I recall, the minimum slope for drain pipes making it the bare minimum angle to encourage the flow of water. I assume you are not using shingles since the min rise to run for shingles is 3:12 (3 inches per foot). What is the roofing material? __________________ ♠ ♥ ♣ ♦

01-04-2006, 12:14 PM	#4
busterb NSABFD Join Date: Jul 2004 Location: MS. usa Posts: 3,908	Looks like the answer is 25 times .25 for 61/4 or 6.25. What is the roofing material? It's in link above thanks. __________________ I've haven't left very deep footprints in the sands of time. But, boy I've left a bunch.

01-04-2006, 03:56 PM	#5
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	They're showing 3 different materials in that link, Buster. __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

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