Guest User
5/9/2009
I have a 50 year old home with a 2/12 pitch and 2x6 T&G doglas fir ceiling. We are replacing old tar and gravel roof with a metal roof and want to insulate on the top of the T&G roof decking. We have had conflicting advice on how to go about this and here is one roofing company suggested: 1. Install a 30# felt underlayment. 2. Install 2" ISO rigid insulation, fastened with 3" plates and screws. 8 fasterners per 4x8 sheet. 3. Install a 30# felt underlayment. 4. Install Taylor Snap-Loc 24 guage galvalum metal roofing system with kynar 500 paint. Is this a correct way to install metal roof? For your information, there is no attci space for ventilation. Thanks you for your advice or input.
Guest User
5/10/2009
Ask bruce and dana inc. they have been in the metal roofing business since 1964. They have a plant located in salem, I think taylor has one their to. I have always delt with a guy named mark, and he has always been very helpful
Guest User
5/10/2009
H.K., The company gave you good advice if you want to insulate the roof. One thing to watch for if screws that are too long. You do not want them to penetrate through your ceiling. [email protected]
Guest User
5/10/2009
Thank you for your input, but I am confused about installing two layers of 30# felt, one over the roof decking and another layer over the insulation. Is it standard? Thanks.
Guest User
5/10/2009
H.K., You wouldn't have to put a layer of felt under the insulation. We do it so that when we tear the roof off of one side of a building, we can immediately get in the dry in case there is rain. We can then not worry about it getting wet inside while we lay out the insulation panels and metal roof. It isn't going to hurt anything (except more money from your pocketbook) for the extra layer of felt. Personally, I feel that it is cheap insurance should something unforeseen happen.
Guest User
5/12/2009
Thank you for your advice. One more question. The house is sitting on a bluff on salt water, and at times the wind blows very strong. By using the method my roofing contractor specified, I am wondring the metal roof would be secure or is there a possibility of lift-off effect.
Guest User
5/30/2009
Wade, I was advised by another contractor that I need to put down 1/2" CDX plywood over the 2" ISO insulation to keep the metal down firmly without the rocking effect that would occur otherwise due to the thin layer of insulation board(2"). I would like your opinion on that. Thanks.
Guest User
5/31/2009
H.K., You can put OSB or plywood down over the insulation. We ordinarily use purlings screwed to the deck every two feet. Either way it gives you a firm base to screw to. The purlins is less expensive than the sheathing. All I have ever used here in Texas is 4x8 sheets of ISO board. We use a table saw and cut it exactly in half. We band the house with 2x4's. We then build the 2x4's up to match the thickness of the insulation we are putting on. If it is 2" we put a 1x4 on over the 2x4. We but a row of out 2 foot iso against the bottom band, we then but our first row of purlins against the iso, then another row of iso and another row of purlins, all the way to the top. It gives you a solid surface every two feet across the roof. When we use plywood, we do not align the joints of the plywood with the joints in the ISO. I hope this helps. [email protected]
Todd Miller
Classic Products, Inc.
6/1/2009
Thanks Wade. Sorry I have been running a lot of different directions and not on the board much recently. Trying to improve on that!
Guest User
8/11/2009
What material do you use for purlins?
Guest User
9/20/2009
Most manufactures recommend red rosin paper as it don't break down and crumble and most important.... it don't glue itself to the metal. The sticking to the tin part is going to buckle the metal and tear eventually is like nothing is there good luck.....
brandon knox
12/11/2009
i was wondering if you can install a metal roof over cedar shakes
Todd Miller
Classic Products, Inc.
12/11/2009
Most metal products will have options for doing this.
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