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TOPIC: Flat Roof

flat roof

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we have a flat roof on a house in florida. it is located within 500 ft of the mouth of a large river that feeds to the gulf of mexico. what is the advisibilty of adding a metal roof? thank you, tom
Guest User

5/8/2002
The entire roofing industry has come to recognise that there should be no true flat roofs regardless of material as water always ends up ponding someplace which leads to accelerated wear on the roofing material. A minimum pitch of 1/4" in 12" is recommended today. Having said that there are many metal roof systems designed for this low slope application however they are "commercial" in nature and have high (3") seams which may not fit your architecture. The harshest salt air environment is within the first 500 feet of the ocean and depreciates rapidly after that. As you are on a river removed from this environment a Galvalume roof would perform well given the above conditions. The commercial roof profile required for your application would only come in heavier gages which may put it out of your budget range however of the positive side, you would never have to worry about a tropical storm blowing off a metal roof. Good Luck.
Allan Reid
Dura-Loc Roofing Systems, Inc.

5/8/2002
I am designing a deck to be installed over the top of a 16' x 15' "flat" roof. The roof has a 1:48 slope. Tapered floor joists are to be installed directly over the roof joists which are 16" OC; the joists and weight of the deck will set on top of the roofing material. The roof lies on an inside corner so it is bounded on two sides by walls that would have to be flashed; the slope of the roof is away from one of these walls. The roof material will be completely out of sight so appearance is irrelevant. Is a metal roof an economical option? If so, can you recommend what type and steer me to an appropriate supplier and installer? Thanks.
Guest User

5/8/2002
What is the recommended minimum pitch for a metal roof that is not "commercial"? Does it still have vertical seams?
Guest User

5/22/2002
Most of the shake, shingle, slate, and tile profile products have a minimum 3:12 pitch. A few are 4:12 minimum. Most vertical seam products have a 2:12 or 3:12 minimum pitch. The exception would be mechanically-seamed "industrial" products that go as low as 1/4:12.
Todd Miller
Isaiah Industries, Inc.

5/22/2002
I want to build a garden room on a north facing wall of my house. To maximize the visual connection to the garden a low slope roof is desirable (i.e.,1" per foot). Would this be effective in snowy Ottawa Canada? How close to the overhang of the existing roof is appropriate for the new roof? Can you recomment a metal roof for this application? Are there other considerations here?
Guest User

5/26/2002
As a fellow snow bird you are on the right track however there are a number of situations that can negatively impact what you are trying to do. First you should be careful on what roof area,type and slope there is above your intended addition and the distance between the roofs. If you were joining the roofs you need to be careful that you do not back the water up under the upper roof. As weel you need to make sure that you have taken into consideration the volume of rain and snow that could feed onto the lower roof. If the roof diferential is too great you need to design in the strength required to resist any avalanching snow or ice. As well if be careful not to block off your soffit ventilation by going too high. Consult your building inspector on this. Having said all that, under normal circumstances you should put a solid deck down and cover with a good quality ice and water shield. Depending on the roof system chosen, and because it is facing North, I would reccommend strapping the roof vertically first then horizontally. This will allow for a cooler roof and elliminate ice damming and if any water was to back up it the ice and water shield would guide it down and out. Try to keep the roof junction below the other roof line if possible. Once you chose a rough design and a certain material, check with the technical department of the manufacturer.
Allan Reid
Dura-Loc Roofing Systems, Inc.

5/26/2002
I would like to know if you can install a metal roof on an almost flat roof? I have a ranch house with large overhangs. I have had problems with ice damming on the south side of the living room. Iam in the process of tearing off the original tar and gravel roof. I am not real happy with the prospect of putting an expensive rubber roof on this place. Any ideas of help would be most appreciated.
Guest User

5/17/2003
As you investigate various metal roofs, you will find that their manufacturers specify minimum pitches. These minimum pitches must be adhered to. Generally, the metal roofs which can be used on nearly flat roofs are vertical seam products which, after the panels are put down, are field-seamed with a special machine. One other option is, with the low weight of metal, to consider building up the pitch of your roof. You will probably need to have an analysis done by a structural engineer to see whether this could be done on your house.
Todd Miller
Isaiah Industries, Inc.

5/17/2003
I have a townhome and part of the roof is flat and the other half is pitched with Mexican Tiles. To put in the metal flat roof - do you have to remove the garvel and tar? Can you put metal over the Mexican Tiles?
Guest User

8/18/2003
The world should never have made flat roofs. Metal roofs require some slope to shed the water. I would suggest that you need to identify if the roof is acually flat and how it discharges the water. If it drains into a drain you will be best to have a high quality membrane rofing installed in this area. As to the tile section, virtually all concrete tiles and most clay tiles rely on a secondary membrane to be weather tight. You should remove this roof and run the flat membrane up the slope a certain distance and then install you new metal roofs. A number of us do make a tile facimilie in metal. Have a look at ours at www.duraloc.com.
Allan Reid
Dura-Loc Roofing Systems, Inc.

8/19/2003
I have a roof that is approximately at a 1/12 pitch and wonder if metal roofing is for me. I would very much like this time to be the last time that I have to re-roof(every 5-7 years is getting old). Please let me know if metal is a good choice for my situation. Thank you,
Guest User

8/19/2003
Very few metal roofs are appropriate for this low of pitch. However, if you can locate a product to your liking which its manufacturer approves for this low pitch, then I bet it would make a great choice.
Todd Miller
Isaiah Industries, Inc.

8/24/2003
I'm trying to get some opinions on a new roof. I have a 2:12 gable roof, no valleys, tar and gravel, that will need replacing in a year or two. We would like to go with a metal roof. I have a bid for a screw down panel type roof. Is that a problem with a low pitch? Water runs off the roof very well, no ponding at all, and we live in Central Texas (no snow). Thank you Trevor
Guest User

8/28/2003
Some screw down roofs are okay for a 2:12 pitch. It is essential, however, that you check with the manufacturer of your roofing and make sure that the product you're installing will be okay at that pitch.
Todd Miller
Isaiah Industries, Inc.

8/28/2003
my flat roof has a pitch of 3 inches in 14 feet---would you recommend a metal roof
Guest User

8/8/2007
This is minimal pitch but it may work for a commercial-grade double or triple lock mechanically seamed standing seam.
Todd Miller
Isaiah Industries, Inc.

8/8/2007