I know you guys are tired of hearing about me and my small flat roof but I have to do it soon and just trying to decide whether I am using Flintlastic or EPDM.
The roof is only 10 squares and is 5/8" plywood with insulation and mod bit roof. I am tearing it off to the plywood. The roof is about a 1/12.
If I use Flintlastic do I have to use Mid-Ply?
If not....do I just attach SA Base to plywood decking and then install SA Cap? What do you use to attach SA Base? Is Black Diamond SA ok to use instead of Certainteed base?
So many questions....
Thanks for your help guys! Randy
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Mike, you are accorded amnesty because those of us who have followed your input over the years are well aware that your codes are set with fully adhered specs. There is no way you can buck that system. Remember, though, that not too long ago you yourself were publicly questioning the validity of that tradition. (2) We don't use any special non-rotting sheathing on our day-in/day-out decks. We use OSB or plywood generally. There is no reason to make replacement of those decks mandatory. Furthermore there is no reason to put everything here down with stainless steel screws either. (3) I stand by my statement and prejudices. With or without protocols for recovering adhered membranes with another membrane, I vastly prefer getting down to clean sheathing, making necessary adjustments, and doing a clean install of the new roof. (Are you listening, Darryl? l o l. ) Just better all the way around imo. If I have the choice, of course. (Which I do.) Btw, I don't fool around with these low-slope membranes. I religiously follow manuf. specs. (I've learned the hard way, believe me) I meticulously inspect and correct the substrate, I install the cant strips as needed, I nail on the base. When I am satisfied that everything is perfect to that point, I install a two-ply mid-ply membrane and detail it to the "n"th degree including base flashings. Only then do I install the cap. I make sure that none of my laps stack up, and I use granules to obliterate any stray cement at joints or flashings. I don't know how long these things will last. Nobody that I know does. But they're going to last as long as it is humanly possible for me to achieve.>>>
Vaaa, Roofing God or anyone else......can you guys post a picture of how to flash a chimney properly using a SA cap?
Do I need a cant strip around chimney? Do you just run base up chimney then do the same with cap sheet, then termination bar with sealant? What about corners?
Thanks!
I am going with either Flintlastic or Liberty 2 ply system.>>>
wouldn't a plywood sheated roof be considered a removeable substrate layer?...or are you suggesting a seperator to allow the entire system to be ripped without ripping the sheathing? I agree with that from a stripping point of view, but if that were the issue, then the same argument for felt over Grace I&W to make shingle removal easier holds ground.
In your scenario...your suggesting that the only way to go would be a SA roofing over a nailable base sheet to simplify removal?... >>>
Don't know who said you cant use on bare plywood but obviously they better stick to sales. Not sure where your from but if ya lay down SA base to the deck when its warm It will stick like a Sob. Then lay your SA cap. Just make sure ya use a roller .I used the GAF Liberty and worked great on many jobs. I don't have the faith to lay it on a dead flat roof though. 1/12 is definitely a good one to use it on.>>>
I used to do a fair amount of hot work, and sometimes we would find a tear-off where the base was solid-mopped to the deck. Naturally it was unable to move at all and split up wherever there was sheathing stress and the sheathing moved. Over time of course. You can get by on one of those for a long time before it flat-out fails. With hotmop, when it's old, you can come in when it's cold and split it down to sheathing to start over properly. You will never do that with an HDPE film sheet stuck down by its modified asphalt adhesive. Never. I have put two-ply Grace Bituthene down on primed plywood more than once with LM fillets and the whole deal. I considered that different. They were covered with tile or concrete or what have you, with essentially zero intention of ever digging any of it up again. I will not, do not, and have not ever rolled down an S/A sheet direct to roof deck. I think it's rude. No offense, but I think it's worse than rude. And yes, if you do that then of course nails are not only unnecessary, they would be dumb. I think we should leave the world a better place than we found it and stuffing oobleck down somebody's trumpet aint better. Now of course if you are installing them on a removable substrate layer, that is a different matter.>>>
Builderr, using I&W as a base would be in my opinion the best way. Good thought. A base sheet fastened would be a must if wind is / was an issue. I have seen rubber adhered right to the plywood. If you need R factor add half inch but not fiberboard thats junk. If both will take you the same amount of time pick the one thats cheaper to purchase.>>>
I like the looks of that Tamko system....my supplier don't sell this system by Tamko, wonder why?
As for Grace..I sure wish I could use that as my base because that stuff is hands down the very best ice barrier I have ever used, flexible in zero weather and always sticky, will not tear!! And the Grace select is a 2 square roll for half the price of the original Grace, can't beat it.>>>
Tamko SA system......SA base acceptable over wood deck.
http://www.tamko.com/Portals/0/documents/TAMKO_SA_Product_Sheet.pdf
and to throw another question into the mix.... anyone ever discus Grace I&W as base for other top plys? >>>
I talked to my supplier today and they tell me I need to use the nailable base since it is wood, they said SA Base is for SA only, no fastners. So here is what I need to decide between. Which is best roof in your opinions.
1. EPDM .060 on top of 1/2" Fiberboard, all glued.
2. Flintlastic...using nail base over plywood then Flintlastic SA Cap sheet?
I am wanting to use Flintlastic just because it seems easier to install and I have never used it...but I bid this job using EPDM and dont have enough bid in to use 3 ply of Flint.
Thanks!>>>
You really need to get the installation specs from the manuf., memorize them, and stick to that. To the letter. Although it may not play in your area, that one in twelve business is likely to affect your fire rating. They have the testing specs for those ratings, too. If you can't find the info, don't use the product. I don't use a (1) base and (1) cap with s/a. Maybe on something that doesn't matter it would fly, but it's just too dicey imo. Your cap is not going to completely adhere because of the base nails, no matter what you do. One mid-ply at least and ambient temperature is all-important. imho. fwiw.>>>
Vaaa....Dont be shy buddy! You have always given me great advice on anything to do with this stuff and I know you have used Black Diamond ;)
Old School....Did you fasten your SA Base and do cap nails work fine?
Builderr...Are you saying if I am going to fasten it I would be better off using a nailable base instead of SA base and nailing as well?
This roof blew off before because of high wind so I need to make sure if it fails that its not because of wind. Thats why I was going to use EPDM.
Thanks Guys!>>>
SA means what it says...self adhered... I take a piece of Ice and water and try it in various spots. If it sticks to everything...then SA base is the way to go... If in doubt, then fasten the base and SA the finish coat. mid ply might add to warranty though. >>>