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TOPIC: Installation Process

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You have a valid point. Most building codes in North America call for an underlayment under all roofing products unless the product has been tested for use without one. This practice is generally to protect against severe weather situations such as wind driven rain or ice daming. Condensation is another form of moisture that is created whenever you get a temperature differance between surfaces and one surface crosses the dew point. Ventilation of enclosed spaces in a roof assembly is a good way to minimize the temperature differances and the resulting number of dew point crossings. Additionally, ventilation will allow the moisture to exhaust to the outside. The underlayment is referred to a moisture barrier in that it should allow air to pass through while trapping the moisture on its surface. If you were using a sheet steel roofing material laying directly on the deck, I would recommend either two layers of #15 or one #30 as the heat will eventually break down the felts. Most important though is to allow for some form of ventilation especially if you consider using a peel and stick type ice and water shield as an underlayment as it does not allow air to pass through. The entire roof structure will last longer if it can breath. Look at the old wood barns that have protected from the weather exposed to the elements for years. They are exposed both sides and can breath.
Allan Reid
Dura-Loc Roofing Systems, Inc.

12/19/2001
Your shigles are probably suffering from excessive heat retention from lack of ventilation which then evaporate the oils in the felts and start to curl and lose their stone. Mild witers can be hard on any roof system without ventilation because of condensation and metal is no differant. Stapping the roof with a 1" board provides a proper fixing point for the fasteners, provide a small air chamber minimising heat transfer and will stop telegraphing of the shingles up through the metal. If your esisting shingle roof is only one layer and not leaking it will work as a good underlayment however you should provide some ventilation regardless of whether it is over a heated or unheated area.
Allan Reid
Dura-Loc Roofing Systems, Inc.

12/19/2001
I'm not sure exactly what metal you are intending to use. Most of the sheet steel products have ribs formed in that are 7/8" high and they will span 1x3 strapping at 16" centers at 28ga. You do need to watch the foot traffic on it during installation as the joints do not gain their full strength until they are lapped and fastened.
Allan Reid
Dura-Loc Roofing Systems, Inc.

12/19/2001
I have just recently purchased a home built in 1950 which has a wood shake roof which is in bad shape. We want to install a metal roof and would like to know if it can be installed on top of the existing wood shake roof, or should we remove the old wood shake and put down plywood boards and then put on the new metal roof. I get various ways to do it and am confused.
Guest User

5/10/2002
Hi Karen, Several of the shingle, shake, and tile facsimile metal roofs, in steel and aluminum, are appropriate for installation over your old shakes. Depending upon the thickness of your shakes, some products might be installed directly over them and others might require a batten system on top of the old shakes. These are very tried and proven installation methods for several metal roof systems. Some vertical panel roofs could also be installed if a gridwork of vertical and then horizontal battens is installed first. Choose some products you like and then inquire with the manufacturers as to their suitability for wood shake re-roofing. Todd Miller
Todd Miller
Isaiah Industries, Inc.

5/10/2002
I am building a house in northwest Washington state (cool, moist environment) and would like to use a standing seam metal roof. This house design calls for a 14" diameter round SolaTube type skylight in the entryway. I was wondering about the proper way to flash this to make it water-tight. The flashing provided with the skylight appears to be designed for asphault shingles. Would it be best to build a 6" high square skylight-type curb, flash around this with metal paneling and install the skylight on top of this platform?
Guest User

5/23/2002
My company manufactures primarily shake and shingle style (horizontally-run) metal roofs. I know that, the first time we were asked about installing the round skylights with our products, we contacted the skylight manufacturer and, together, we arrived at a good installation procedure. My suggestion really would be to have your metal roofing manufacturer contact Sola Tube and determine proper installation techniques. Todd Miller
Todd Miller
Isaiah Industries, Inc.

5/23/2002
I'm considering a metal roof. I would like to install it myself. After some research, I think I most likely would use either standing seam or through fastened, mostly becasue of cost and ease of installation as compared to standard asphalt. How hard would it be for someone who is handy but never installed a roof before to install either of these types of roofs? What are some of the potential mistakes? Also, what are some of the advantages/disadvatages of through tastened vrs. ttanding team. Thanks
Guest User

5/26/2002