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EPDM Slope ?

15288 Views 9 Replies 5 Participants Last post by  oldfrt
I'm going to be getting into a reno for a customer next week. He's a hands on guy and he'll get the roofer both rubber and asphalt to do the house.

Presently there's an addition on the back of the house that extends 10' ft out, 12' wide. Flat roof, tar & gravel. Its covered by a blue tarp now and sunk in. It runs into the main house that is asphalt shingles. They'll be redone too.

I'll take the top off and go back with 2 x 8 or 2 x 10's and plywood deck.

I may not get the info I need in time to know the slope to put on the roof deck for the epdm ? I suppose any slope is helpful ?

So how much slope ? 10 ft run, is 6" too much, 1" too little ? Like I said it intersects with the 4/12 slope of the existing shingle roof. So that's what (water) will be running down on it.

Thanks
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How's about a minimum slope ? I guess that's the question.
Anything that eliminatess standing water. More is better. In Minnesota, decks up to 8/12 are routinely covered with EPDM. So are decks with a drop of 2" in 100'.
Thanks
2.5" per 10' = 1/4" per foot is the standard. Why EDPM on something that small?

or if you can get 1/2" per foot I would go with a peel-n-stick Mod Bit...
Ap- As soon as you said why EPDM on something that small it hit me.....peel 'n stick....the you said it.

I went to the GAF site and checked around. This is the link.
http://www.gaf.com/Content/GAF/RES1/ROOF/liberty.asp?viewer=&module=

Could be an alternative ? It didn't register with me as its not an out building or garage. But the guys going to flip the house and he does spend a bit more than most. Its a mid / upper mid neighborhood. I'll mention it to him. He's asking me.

Clarify this "I would go with a peel-n-stick Mod Bit... " ...bituminous what...???

I can get 1/4" or 1/2" per ft. Thanks, that's the set up I need. Makes sense.
EPDM is fine if there is enough slope to drain any water off the roof within 24 hours of the last percipitation event. 1/8" slope per foot is more than adequate.
One of the last EDPM roofs I did was a 3/12,shed dormer,30' long on the second floor.

Roof worked great,only problem was in the winter when ice build up would come off the roof in huge chunks.
It almost took off a garden window I had installed.
Every winter now HO puts up a structure over the window to protect it and never uses rear entry.

Shouldn't be a problem in NC,but added here to make others aware of a possible drawback or precaution in it's use.
Thanks a lot fellas. The roofers were there today. Got the shingles and EPDM completed. I got about 6" in 12'.

This is a FC in a good neighborhood. The roofer was not calling back and I had to determine with your input a proper pitch for the new EPDM.

The rear room addition flat roof was blue tarped. About 1" slope if that in 12'. Roof / Ceiling joists nailed to the house. I opened the roof and added new rafters from the outer wall to the higher up top plate of the house like its supposed to be. Released and leveled the old ceiling joists now carrying only the dw ceiling upon a new 2 x 4 wall against the house.
Have they considered adhesive snow guards?
One of the last EDPM roofs I did was a 3/12,shed dormer,30' long on the second floor.

Roof worked great,only problem was in the winter when ice build up would come off the roof in huge chunks.
It almost took off a garden window I had installed.
Every winter now HO puts up a structure over the window to protect it and never uses rear entry.

Shouldn't be a problem in NC,but added here to make others aware of a possible drawback or precaution in it's use.
Looked into finding something a couple of years ago,I was afraid that the rubber would get torn with the adhesive guards.
Looked for something that may be attached to the facia instead but had no luck.
Have you used these?
Have they considered adhesive snow guards?
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