flat roof help
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SnowBlaZeR2
Well-known member
Are you asking about the framing, finishing the roof or building the deck on top?
idoine in toronto
Well-known member
I have a similar situation with my roof. It has a slight slope that can either be created with tapered joists or tapered firing strips under the sheathing and membrane. On top of the membrane I have a cedar deck surface over sleepers that are tapered in the opposite direction as those under the sheathing creating a level top surface. Water passes through the flat cedar deck and runs off the sloped surface below. The cedar deck also provides some protection from foot traffic damaging the membrane, but is removable if I need to access the sheathing below to make repairs.
There are other ways to build flat roofs that can also be used as decks but I've always used some variation of this system for residential use.
Aron
There are other ways to build flat roofs that can also be used as decks but I've always used some variation of this system for residential use.
Aron
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Printer Mike
Well-known member
FWIW... Consider avoiding a flat roof.
SnowBlaZeR2
Well-known member
Can I ask why you say that? I've never had an issue with a flat roof.
Pretty much what I would have said.
What are the measurements of your garage?
Ford12508
Well-known member
I think something to ask is where do you live? I am not a home builder, but I would assume you would want something much stronger depending if you get a lot of snow.
regguy1
Well-known member
Flat roofs are a PIA...much more prone to leaking.
have one on a building I own...always something..you want a roof, not a career
SnowBlaZeR2
Well-known member
Flat roofs are a PIA...much more prone to leaking.
have one on a building I own...always something..you want a roof, not a career
I've always used EPDM and never had one leak.
Our last house had an addition with a flat roof, and they installed rolled asphault.
It started leaking before I could get the EPDM on it. After I re-framed everything, gutted and replaced everything in the room and put EPDM on we didn't have a single problem for 6 years when we sold it. I do hate how flat roofs look though.Printer Mike
Well-known member
I am basing my statement on 23+ years of maintaining the roofs on a boat house and a print shop. I'm not saying it's not possible to have a trouble-free flat roof. Maybe possible with some advanced materials...
bobabuee
Well-known member
EPDM all the way for a flat roof, no leaks ,but you need to have someone that is very knowlegeable do it get references and knows how to slope it right and right amount drains.ect...
idoine in toronto
Well-known member
+1!!!
SnowBlaZeR2
Well-known member
I wasn't challenging your knowledge, I just wanted to know why you said to avoid one. A little info other than don't do it isn't unreasonable if you ask me.
It's more than possible with EPDM. I've installed probably about 10 and never heard of one of them leaking. The earliest was my uncle's shop about 10 or so years ago, and still no issues. EPDM isn't really expensive either, especially if you install it yourself.
djjsr
Well-known member
Is EPDM glued down or torched?
SnowBlaZeR2
Well-known member
It uses adhesive. It's sort of like installing laminate counter top, as far as the adhesive goes, if you've ever done that. What I mean, is you put the adhesive on the EPDM and the sheathing, wait for it to get a little tacky and then join them with pressure to get good adhesion.
At least that's how I've always installed it.
Printer Mike
Well-known member
Wonder what the materials would run to do a 30 x 90?
EPDM
EPDM
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metal1313
Well-known member
is epdm the same thing as the large rubberish sheets that cover the entire roof with one piece of material
SnowBlaZeR2
Well-known member
Depending on the roof, it would be around 2k for the EPDM, adhesive and flashing. That's also assuming one sheet with no seams.
*edit*
Also, that's for 60 mil, which is what I use most of the time. Might be overkill, but I'd rather be safe than sorry.
Not sure what you mean, but that's pretty much what EPDM is. A rubber sheet.
Falcon67
Well-known member
We have an almost flat roof section on the old house. It has been in place 12 years, the roofing company used a hot tar mop and roll roofing - zero leaks and damage after two more killer hail storms including the one in 2006.
I built mine like that in chicago and it worked out great. 20' wide, I joist roof was pitched 5" over the 20' with a torch down membrane roof, then 1x12 sleepers centered over the where the i joists were, floating on rubber pads with decking screwed to the sleepers. The railing was a continuation of the side walls of the building for an unbroken outside appearance, sided inside and out. roof membrane details are important, I used 45 degree curb strips where the roof met the wall. Never had a leak, snow and all. runoff dumped into a slot in the side wall, full width gutter, no narrow scupper to clog. actually had a 10' hi ceiling, I made the garage door to run straight up into a pocket using a counterweight and standard electric opener. I would get a lot of leaves, so each spring I'd remove one board at the high point of the roof and hose them out, not a big deal. It took a lot of detail work but was exactly what I needed at the time, fully sheetrocked inside, insulated and heated
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Speaking as a professional roofer, EPDM can be an awesome roof in a residential application I hate them in a commercial/industrial application. You can install EPDM one of two ways, glue down the entire sheet, or glue the perimeter and use ballast(large smooth rock) to hold down the roof. No roof will last forever but since you plan to build a structure over it you will want the longest lasting roof possible so that you wont have to hire a crane every ten years to dismantle the deck and install a new roof. This is only my opinion but from my experience it doesn't take much to puncture an EPDM roof, in fact the material is nothing more than a really thick inner-tube type rubber. My suggestion would be to build some slope into the roof like was previously stated 1" fall for 4' run, use an organic base sheet installed with screws and 3" plates, then torch a layer of smooth modified rubber then a layer of granulated modified rubber over that. This should give you a 25 year( conservative estimate ) roof. Either type of roof will benefit from the deck installed over blocking out the sunlight for the most part, which can shorten the life span of a roof. Use some type of thick rubber to isolate the deck framing from the roof. One more thing, try to incorporate a way to make the deck into sections that float in place preferably small enough for a few men to lift up so that if maintenance needs to be done on the roof it can be without demolishing the deck structure.
Jake
Jake
59 wagon man
Well-known member
my garage is about 10 yrs old flat roof 18' w hot mop torchdown no leaks seems fine but the roof is pitched 4" in the 18'w and no soigns of any leaking.
one day i hope to take inspiration from the garage journal service station and build that overhang moving the gas pumps from the front to the side so i can drive under it and have some shade outside to wash the cars here in sunny south florida. if you have any snow load stay away from the flat roof.
one day i hope to take inspiration from the garage journal service station and build that overhang moving the gas pumps from the front to the side so i can drive under it and have some shade outside to wash the cars here in sunny south florida. if you have any snow load stay away from the flat roof.
+1 They are more trouble then they are worth! You will spend more time fixing it. If you do go with it use a EPDM or better but similar sheet roofing material not tar and gravel.
emercaughfield
Member
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- Jul 30, 2012
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It is a good decision. You should first search a good roofing company which constructs your roof. You can search them online or can get their information from friends, relavites, neighbours etc. After searching a good roofing company you should check it's market value, it's licence etc and then make your job done.
EPDM is a good choice for flat roof as it is very beneficial in many ways and is very common now-a-days. It is very light weight, easy to instal, waterproof and require less maintenance.
EPDM is a good choice for flat roof as it is very beneficial in many ways and is very common now-a-days. It is very light weight, easy to instal, waterproof and require less maintenance.
darcyh
Well-known member
rslaback
Well-known member
I use to install EPDM with my father. It goes down slick and we never had a problem with the roofs. Just put a little pitch in them and you will be fine.
As far as putting a deck on one my suggestion would be to use an EPDM roof pitched straight to the outside at about .3/12 or so. Then build a deck just like you normally would. Have the deck not even touch the rubber. Freespan from the building out to "posts" attached to the sidewall at the front edge. As long as there is nothing touching the rubber it won't wear through anywhere. The deck blocking the sun will prevent the rubber from deteriorating and cracking and the system should last a pretty long time for you.
As soon as you set a post on top of the epdm (even with a pad) it will move in winds, earthquakes, thunderstorms etc and eventually wear a hole in the rubber.
As far as putting a deck on one my suggestion would be to use an EPDM roof pitched straight to the outside at about .3/12 or so. Then build a deck just like you normally would. Have the deck not even touch the rubber. Freespan from the building out to "posts" attached to the sidewall at the front edge. As long as there is nothing touching the rubber it won't wear through anywhere. The deck blocking the sun will prevent the rubber from deteriorating and cracking and the system should last a pretty long time for you.
As soon as you set a post on top of the epdm (even with a pad) it will move in winds, earthquakes, thunderstorms etc and eventually wear a hole in the rubber.
Scott H in Wheaton
Well-known member
If at all possible build the garage with a sloped roof, and build a deck on the ground.
Roofing only 12 years, but I have grown to hate flat roofs. They seem to always have a problem somewhere. Roofs should shed water, a lot of flat roofs retain water.
Check with your homeowners insurance about the liability of putting a party deck on a roof.
Roofing only 12 years, but I have grown to hate flat roofs. They seem to always have a problem somewhere. Roofs should shed water, a lot of flat roofs retain water.
Check with your homeowners insurance about the liability of putting a party deck on a roof.
Stuart in MN
Well-known member
Zombie thread from five years ago, brought back to the top by a spammer.