Replies

1. 
   Kwan_Choi | Mar 22, 2000 11:18pm | #1

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   Flat roofs have many things going against them, one thing being that they present least desireable conditions for insulation against summer heat and winter cold. If you are expanding your livingroom into this patio space, I would not use flat roof. The roofing materials also either cost more or don't last as long as the pitched roof. EPDM(rubber) is costly and other material made of asphalt last about 8 to 10 years. Flat roof also present more chances for leaking. If you plan to walk on the roof, separate floor needs to be built. If you have the budget, go for the best materials. If not, avoid flat roof. Hope this helps and please do more research.

2. 
   Guest_ | Mar 24, 2000 01:34am | #2

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   Respectfully, a well done flat roof, tar and gravel will last upto 40 years. It is a 5 layer process and must have slope to the scuppers. Also, a rubber, torch down membrane is typically 2 layers and lasts upto 40 years as well.(according to expectations... they have only been in use for about 20. Ask your potential roofer for a reference from a previous flat roof client, more than 5 years ago, and speak to the client.

1. 
   Guest_ | Mar 24, 2000 02:16am | #3

   *we do many flat roofs, same basic conditions as you..but i never like a "FLAT ROOF", i always either build in a little pitch, or build up a little pitch, even 1 in 12 is good, if you use the bulkhead and baluster rail, you may even be able to hide a 3/12 roof and use conventional roof shingles..for low-slope, if appearnace is not important , we use a 65 mil fully adhesed rubber over 1/2" hardboard.if the roof is visible or esthetics is a cconsideration, we use a modified bitumen with a mineral grain surface... my favorite is Colphene by Soprema usually over a 1/2" cdx ply, with a primer, and the Colphene is a 36 inch"" sheet membrane with a peel release back...frost color only..if you need colors .. Monsey also makes a 36 inch"" granular modified self -stick "Low-slope" light brown, frost, or black...neither is intended for high traffic, but occasional traffic is fine.....any good roofer will have these skills in his bag...along with a few others that we don't do...like "torch-down"

3. 
   Ron_Budgell | Mar 31, 2000 02:37am | #4

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   For a flat roof used for a walking deck, go to a product like Duradek (which I think is vinyl). It's applied only by certified installers, is expensive, but carries a warranty that's not a joke and lasts pretty good even under heavy traffic.

   I have also used another Soprema product for this purpose, the torch-on modified bitumen roll roofing they call Antirock. A supplier I used to buy from torched some of that onto the concrete loading bay of their warehouse. They didn't bother to sweep the concrete completely clean first so there were a few little rocks under it. After two years of truck traffic on top of this stuff, you could see the rocks clearly, but they hadn't punctured the membrane. Amazing stuff.

4. 
   Guest_ | Mar 31, 2000 03:50am | #5

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   Yikes!!! "Flat roofs have many things going against them"????? Sorry Kwan, but the biggest thing flat roofs have going against them is not being understood by DIY's and misinformed homeowners.

   As a commercial flat roofing contractor way up north ( Canada eh) I have to take exception to everything you said. ( we also do residential shingling so I am not totally biased)
   First of all, it is very easy to add insulation up to any value you desire by installing thicker insulation. We have installed up to R40 on a freezer building. To add thicker insulation you just have to build up the edges with wood blocking to the height of your insulation.

   Flat roofs in our cold winters / hot summers typically last 20 -25 years or longer if they have a good slope to them. That is EPDM (rubber membranes), modified bitumen or the old tar & gravel. Asphalt shingles last roughly the same depending on quality.
   Yes they do cost more typically, but are cheaper than framing out a pitched roof.
   Flat roofs only present more chances for leaking if they are installed poorly.

   Dana, if the flat roof suits the house lines and would look better than a pitched roof, by all means use a flat roof. Be sure to have it installed by a reputable flat roofing contractor. It is not a DIY project. Use either EPDM or modified bitumen and build in a slight slope. Even 1/2" in 12" slope will be dry 1 hour after a rain storm which is ideal.
   You can either insulate the joist space, but make sure you have adequate ventilation above the insulation, or have the roofer install insulation on top to the R value typical for your area on residential construction.
   If you want to use the area as a deck then either have a wooden deck installed on top on sleepers ( flat 2x4 PT) or use a product as Ron suggested which is a PVC, which is made to be used as a deck.

   Hope this helps, don't shy away from a "flat" roof if it will blend into the design of your house better.

1. 
   Guest_ | Apr 02, 2000 04:28pm | #7

   *Dana, just one additional comment which may help.. I am in CT also & have 2/12 and flat roof sections on my 35 year old house. They are original, tar/gravel, and never presented a problem (despite dire predictions to the contrary). There are several experienced roofers around here which know their way around a flat roof - let me know if you need a few names. good luck!

5. 
   Dana_Cox | Apr 02, 2000 04:28pm | #6

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   I am comtemplating enclosing a patio for 4 season use. Is there any way that a flat roof could be used? I am in CT and have seen these rooms attached to old colonial-style homes. The roof appears to be flat and there is a balustrade along the top. I think that would look the best with my existing roof lines and older home, but have always heard that flat roofs are not an option in this part of the country. Any wisdom?