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Discussion Starter · #1 ·
I signed an agreement today with Feasel Roofing. The guy that showed up was on top of his game, willing to to what I wanted and priced right.
I want GIWS over the sheathing, he is selling some underlay called Sharkskin. The project was bid and agreed with this stuff but included an 'upgrade' clause. Ol#2 deflected him while I did a quick web search and the stuff appears better that Titanium but I am still concerned about the screw penetrations. GIWS just appeals to me as being a better product in this application plus it claims a 5.7 PSI tensile strength which adds a significant amount to the roof structure.
Opinions?
 

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A hurricane that removes the roof will rip the GWIS anyways. You would still have holes in the GWIS if the fasteners pulled out. What type of roof deck is it? Plywood? Plank? T&G?

I have stated before that all evidence points to the need of an equillibrium in moisture betwwen the roof deck and outside. This keeps your roof deck intact.
 

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Discussion Starter · #3 ·
The deck is ply.
I watched a GIWS covered deck go through 2 hurricanes intact. Every other underlay went to pieces including some of the felt under my shingles. I think that small holes would cause less damage than large missing pieces.
I went with 26ga Century Drain as it gets screwed down every 9 ins. as opposed to 12" on the 5V crimp.
 

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If the GIWS has been down for any length of time, it is unlikely to come off...unless the plywood rips off. Yes, the nail holes would be open. A dime sized spot of cement on these will make it watertight quickley. Grace gave away 1400 rolls of GIWS in affected areas after the first hurricane last season, some of these temporary roofs went through a second storm...and survived.
Sharkskin is a synthetic underlayment, like TriFlex 30 & Titanium....relies on nails to hold it down. GIWS is self-adhering.
Jim
 

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Knight of Ni!
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Hey Teetorbilt thanks for the welcome and yes we should have bought in Jensen! Happy to hear you're getting metal, before I could even talk to you about it... boo hoo! Really tho I don't know how long it would have taken me to get a spare minute and get down there.
We live about 4 knots S. of Sebastian inlet where the windmeters recorded 160 MPH (and then snapped off) when hurricane Jeanne came thru. We had not one failure of our roofs last hurricane season. In fact nobody called about even leaks. I'm sure some of our north facing off-set vents must have allowed some water (altho we have N. facing offsets on our place and not a drop?). The only noticeably obvious failures were Standing Seam systems by a certain company by the name of #$%&^$# roofing company. My point is GIWS seems to be overkill (we call it peel and stick) but I know you've got to feel comfortable with your choices. Most importantly (I think anyway) 2 things; we strongly suggest 24 gauge and take great care to plant extra screws at what i call the leading edge of a roof (unless it's planking), you must be carefull not to split planking with too many screws. The leading edge is near the drip of course where the wind will start to lift whatever roof product you have. Screws in the middle of the roof are nice to see but they don't have much of a job to do compared to that leading edge. What kind of venting are you getting? What about the flat patio... going with slope? metrfr.
 

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Discussion Starter · #6 ·
Metal, As stated before, this guy walked in with all of the right answers. His company has been based out of Ft. Pierce for many years, add another level of comfort. We had the option of 24ga. 5V screwed at 6 on the perimeter and 12 in the field or 26ga. Century Drain screwed 4-1/2 X 9, I opted for more screws. The Century also has additional ridges which should help prevent oilcanning.
I'm going with ridge vents. The cheapies that were here originally didn't leak even though they got a little bent. I also have a cathederal cieling over the grand room and I'm not sure what anyone will run into there with a different venting system.
I'm headed to the B.Dept soon with some plans that I drew up yesterday. I can't imagine why it won't fly as it will be the strongest part of the house. LOL
 

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Knight of Ni!
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The extra striations in that profile do make oil canning almost non-existant. We use a similar profile called master rib. I/we made a decision about 5 yrs ago to do only metal roofing, do it as economically as possible to reach more people and still do a quality job (read dade county specs) I really believe in my heart that shingles should be outlawed. I'm talking primarily coastal Florida now guys so put down your guns! ;) This last hurricane season has us looking (and feeling) pretty good about that choice. The plan is to cover every roof in FL with metal, it doesn't matter who does it. You are one we will strike off the list. :Thumbs: Nice call. M.

P.S. I'll buy the first round!
 

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Discussion Starter · #8 ·
It isn't often that one gets to view the damage caused by 2 hurricanes in one month. I made many notes on trees, construction and roofs.
I saw virtually no wind damaged metal roofs. The metal also reduced damage from impacts.
I'm with you, all homes in zones 1+2 should be required to have metal, zones 3 and up should be encouraged through ins. reductions.
I'll be up that way in a couple of weeks.
 

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I think youve made a good choice, Teetor, and I don't install a whole lot of metal roofing. It is a luxury item up this way. :)
 

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Discussion Starter · #10 ·
I can understand that, metal is about twice the price of architecturals. Here, it's cheap insurance considering what it is protecting. My neighbor says his cut the power bill by $50.00 a month, that's not bad either.
 

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Teetorbilt said:
I can understand that, metal is about twice the price of architecturals. Here, it's cheap insurance considering what it is protecting. My neighbor says his cut the power bill by $50.00 a month, that's not bad either.
What kind of metal are you referring to as being twice the cost of shingles, must be those cheap exposed fasteners systems, In this area you will mostly only see that on polebarns and some houses. In more populated areas those panels are a little to rural. Doesnt the steel and the fasteners rust out down in FLA.?
 

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My take on exposed fasteners is this, say the average roof is around 3,000 sq. ft. of area. The rule of thumbs is one fastener per foot. That means you have 3,000 holes in a brand new roof. Plywood is not a perfect substrate and can have soft spots and interply voids which may have an adverse effect on the seating of screws. Also, the most common exposed system is 2' panels cut at the desired run. Anything over 22 feet in length is going to pull at the fasteners at the top 1/4 and bottom 1/4 of the panel. The fasteners may not back out, but the penetration around the screw will become elongated, guaranteed. Exposed fastener systems for anything but a barn or outhouse is garbage.

A standing seam system with concealed clips and hemmed at the eaves on a continuous clip is a far cry better. It's much better to let the panel float on the clips, than to have it straining against screws. I have installed thousands of squares with no call backs, unlike exposed systems.

Just food for thought.


Best Regards,

DE
 

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Discussion Starter · #13 ·
DE, It's a little late now but I wish that you were here last Sept.
My log shows that the only roofing systems that showed 0% damage were metal or cast concrete. Concrete came in during the 40's-50's. Some of the metal roofs had already survived the hurricanes of '26, '35 and '47.
I understand the expansion/contraction rates of metal but the proof is in the pudding.
 

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Is it an exposed fastener system? i was thinking you were gpoing with standing seam w/hidden fasters. I have only done one ofthese roofs, but it sure was a nice roof to do. I see it all the time, and it makes me happy. :)
 

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Discussion Starter · #15 ·
Standing seam made me nervous for three reasons.
1) You can't be assured that the retainers are going to be applied as stated.
2) I fail to see how the retainers are as strong as through fasteners. Remember, I'm an Engineer.
3) The panels are 24" and only retained on the edge, combine that with bracket type holddowns and there are just too many different forces at work.
 

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Discussion Starter · #16 ·
I really dislike hammering on this subject but the time is down to 6 wks.
What is wrong with ridge and gable vents combined? About 50% of the homes here use both. Being in S. Fla, heat is much more of a concern than cold and we laugh at ice problems. We did have a freeze about 20 yrs. ago, lasted a whole night. Still no chance of ice dams.
My house faces east, so that the gables are oriented N-S which is where our predominate winds blow. The entries are small, about 18 X 18 and everything visable is perfect. We almost always have a breeze/wind/ seabreeze.
Can this many builders/roofers be wrong or is this a local variation based on conditions?
I spoke with Hardie today and their trim products are not suitable for here without backup. Too thin and won't hold screws for structural guttering.
 

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Teetorbilt said:
Standing seam made me nervous for three reasons.
1) You can't be assured that the retainers are going to be applied as stated.
2) I fail to see how the retainers are as strong as through fasteners. Remember, I'm an Engineer.
3) The panels are 24" and only retained on the edge, combine that with bracket type holddowns and there are just too many different forces at work.
1. Then you dont have a good subcontractor, if you cannot be assured.

2 The system I put up some times is a 12" wide panel that has clips every 12"
screwed in place.( 2 screws ) More clips, and thicker material combined with a good seam lock ( double lock comes to mind ) would provide a very strong system

3. My understanding is most of the major manufacturers dont make a 24" conceled fastener system.

The exposed faster system are just as costly than an asphalt shingle over a period of time. Maintance.
Many homes owners think metal roofs are all the same..

That said, I am seriosuly considering offering exposed fasteners systems now, the good products are very costly, not everyone wants to drop the big money.

In theory the ridge , soffit vent system is the most efficient. I am not from the area to understand fully the differant weather varibles involved and what type of system has performed best in your climate.

I read the question wrong about the vents. IMO as you describe , the venting should be ok , with the gables acting as the intake and the ridge as the exit.

Use a wood subfascia to make sure of your gutter attachments
 

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Discussion Starter · #18 ·
Sorry, I should have mentioned that I also have soffit vents. I got it all.
Like I said, about every other house has the same.
 

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Teetorbilt said:
What is wrong with ridge and gable vents combined? About 50% of the homes here use both.

I suggest you visit the Cora-Vent website. I'm sure you can Google it up. They do not advise the use of gable vents in conjunction with ridges vents for fear of creating an adverse flow. As for being sold on exposed systems, thats fine, I understand. I've had a lot of calls of regret from people who passed on standing seam for the cheaper exposed systems.

Let's find out how good your roofer is. When he applies the metal, look at the seating of the screws. The rubber grommet/gasket should barely buldge from the metal cap. If it doesn't barely buldge, then its not down tight enough. If the rubber is squished out from the cap, then its over driven. I'm sure your diligence with being a nit-picking engineer will drive the roofer nuts, but thats good. IMHO, anyone who pushes exposed fastener systems on residential should be driven nuts.


Best regards,

DE


PS- I'm looking forward to the posting of a slide show for your newly completed roof. I'm sure the cast of thousands here on this fine and noble site would be most happy to offer up the critical reviews.
 

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Discussion Starter · #20 ·
Slide show? I'm still trying to figure out how to post a pic. LOL I managed one or two and did so much stuff that I forgot what actually worked. I think that Yahoo Photo's was the one that worked for me.
 
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