Re-roofing questions

[scofo]

Hello all, I'm going to strip the 10yr old composition shingles off to the 1/2inch osb deck, due to hail damage from last spring. Plan is to recover with 26guage white concealed fastener 16" wide metal roofing on a 3.5/12 pitch with ridge vent most of the length.

The first material estimate I got had synthetic underlayment on the quote.
I've read up a little on this stuff and it looks like it might worth the extra $ over 30# felt paper. Any opinions on this new to me underlayment? Instructions call for nails with caps no staples.
Seems to me those nail guns with the plastic caps would be too thick to put under sheetmetal. I guess I could **** it up and hand nail all the underlayment.


Any tips on this project? I have never stripped a roof but I have done some small scale roofing projects with asphalt shingles before and I'll have help from my grandson(s)

Also I need to replace the broken plastic skylight bubbles with some real skylights.
Thanks for any help. Scot

 

[Kevin54]

If I find that I am going to be roofing rather quickly AND the weather cooperates, I staple the felt paper with a hammer stapler. The plastic caps do tend to create bubbles that are noticeable especially on a standard three tab shingle. I find that I can get felt paper down quicker with a hammer stapler also. Now if the weather predicts I will use the cap nails. But wither way, you should have no problem with the metal over them as you will not see movement out of either. And the plastic caps won't stick up much more than the metal clips on your sheeting anyways.

 

[NWOhioChevyGuy]

I used the "engineered" felt on my home for under a laminate shingle, I just used a hammer stapler and stapled it down. It has a longer exposure rating, so when I did my roof by myself it gave me all summer to get it covered up with out pulling or bubbling up like felt would have.

My younger brother did the cap stapler thing on his house last year, the gun is kinda a pain and afer doing mine with the staples I wouldn't hessitate to do agian. Plus the caps and staples are kinda pricey.

Just don't be stingy on the staples and it will work fine, and get the steel on before any high winds. The cap staples make the underlayment rated for hurricane force winds, that is why they recommend them.

I wasn't concerned with that in Michigan.

 

[AMCguy]

I'm with NWOhioChevyGuy. On my shop I used Grace Tri-Flex 30. It allowed me to cover my plywood deck in the fall, finish inside in the dry over the winter and do the shingles in the spring when I had the money. They recommend cap nailing but I used staples. It worked fine.

This winter, my wife and I are doing the roof on the house. We couldn't get the Grace product without a mortgage. They relocated their manufacturing and getting it here is too costly. We found IKO Cool Grey to be as good a product. We tore off in October and got the Cool Grey down in two days. Did the front one day and the back the next. Here it is February and were almost done.

These products are worth their weight in gold as far as I'm concerned. We never could have done the jobs ourselves and taken this long to do them without them.

 

[scofo]

Staples are out, with the synthetics I'm looking at, according to the manufacturer must be nailed with caps.
This is going to take a month of weekends probably to do everything I want, Check the duct work [vaulted ceiling thruout no access], blow in more insulation, etc... Weather in the spring is kinda unpredictable normally and this year, man who knows what to expect. Anymore opinions greatly welcomed. Thanks.
Sorry AMC my post showed up after yours Thanks.

 

[scofo]

AMC did you use staples for the IKO stuff as well? Any tears?

 

[scofo]

I'm looking at Titanium UDL or Palisades Kool Blue.

 

[alexb2000]

Depending on what brand of underlayment you use it may not be an issue, many are adhesive backed. You only use the cap nails to hold each piece in place along the top 2" until you can peel back the adhesive cover. Once stuck down you can pull the cap nails out and lap over the holes with the next piece (although underlayment is self sealing for nail holes if its windy and you have to put a couple in the middle or bottom edge). I believe the reason to use cap nails vs. staples is the underlayment doesn't usually have as much fiber cross section as felt paper and it needs more surface area to keep from pull through. On an exposed fastener metal roofing system I feel the underlayment is a necessity since you will almost always develop one or two small leaks as the metal and fasteners expand and contract. Underlayment is basicially another roofing system without a wear surface, so in the case of exposed fasteners is prevents any small leaks from getting past. On a covered fastener system I would think you would be fine with 30lb. and staples, since you won't have the above mentioned issues.

Regardless, make sure to follow the roofing system manufacturers recommendations exactly if they specify one or the other. If you ever have a warranty issue (yes, I have had them) then you are covered. In a warranty scenario the first thing they do is send a representative to find out if the system was installed according to their recommendations.

If you do end up needing to cap nail don't waste your money on a cap nail gun for one job or even 10. Use a magnetic tip roofing hammer and you'll fly through it almost as fast as a hammer tacker.

Another tip if you don't do this professionally is to get a large dumpster put right along side you house for the tearoff. Singles are very, very, heavy and not worth the twenty trips to the dump or the wear and tear on your vehicles.

Since, you are already considering the telegraphing of bumps and surface imperfections from a cap nail, take a good look at the roof deck when you finish the tearoff. Many times OSB decking has sagged between the rafters and while it may have looked fine with comp. it won't with metal. If you need new decking go with a radiant barrier decking (get this from a roofing supplier not Home Depot), worth every penny in my opinion.

The one complaint usually heard about any metal roofing system is noise when it rains, etc. You might consider this, especially if you have vaulted ceilings in your bedroom etc.

Make sure to study the manufacturers recommendation for valley construction since that's where any issues with any roofing system will pop up.

I hope this helps.

 

[AMCguy]

scofo, There are many products out there. You will have to listen to many a sales pitch in order to come up with the best product for you. I know they all want you to use a disc nailer to instal their product. The reality is (in my opinion) if you have a roof leak ten years down the road, you'll be going after the roofer or the manufacturer of the roofing, not the manufacturer of the underlayment. The fastening system has nothing to do with the performance of the underlayment once there is a roof covering it. It only helps keep the underlayment down in high winds until there is a roof to do that. If you feel comfortable with staples use them.

I used 3/8'' crown staples in my Bostitch tacker. About one every six inches on the overlaps and one every two feet in the body of the sheet. I found you have to use quite a few staples in the top of each sheet to keep it in place so you can stand on it while installing it. That gets covered with the overlap though.

I found the IKO product will tear if you try to cut it with a dull utility knife. It is essentially lumber wrap with a non-slip coating on top. If you lift it up (like the wind would) it will generally pull the staple out before it tears. The Grace product is truly higher performance in this regard. You can not tear it period.

In either regard these products come in thousand square foot rolls that weigh only about thirty pounds. Try lifting a roll of 30 pound felt with one hand. I paid $125. a roll for the Cool Grey.

 

[scofo]

alexb2000 good tip on the dumpster, just saw a square of shingles weighs approx. 225 give or take and my roof has to be 20 to 23 sq. Do you think anyone [recycler of some sort] would want them in exchange for the dumpster use and transport? If not I wonder if I spent time to remove the staples if they'de be of use as a driveway covering as I'm in the sticks with a rough and rocky drive and room to pile them in the meantime. Sounds like a ton of work but maybe someone knows if it is feasable.

AMCguy,
I'll be the roofer, so no one to go after just what to do it right and learn from the collective. Thanks guys.

 

[kellyztrukz]

If you are using 26 gauge metal the cap nails will transpose through the roof. Some manufacturers suggest using regular comp nails to install thier felt. I have experiance with some of these felts and I like feltex's product the best, It is easy to walk on ( not as slippery) as some of the others. The one time that we used Palasades we experianced alot of leaks, it was installed to manufacturers recomendations and caused me alot headache. Titanium UDL is a good product. The also have a product called Titanium PSU which is a combination of Ice and Water Sheild and synthetic Underlayment. It has a peel and stick back with the synthetic on top. So no fastening is needed. If you are going to leave it for awhile some fasteners would be added insurance from blow off. When you decide on what manufactuer for the metal be sure the material has a kynar coating instaed of the smp coating. You will get a much longer lasting product.The paint will not fade over time. A great website to visit is metalroofing.com. Also check on the tax rebate you could recieve for using metal. Alot of companies offer this for people. Good luck

 

[scofo]

Thanks Kelly.
"If you are using 26 gauge metal the cap nails will transpose through the roof. Some manufacturers suggest using regular comp nails to install thier felt."
What's a comp nail? Is it a regular roof nail thru a tin cap?

"The one time that we used Palasades we experianced alot of leaks, it was installed to manufacturers recomendations and caused me alot headache. Titanium UDL is a good product."
Good to know.

"When you decide on what manufactuer for the metal be sure the material has a kynar coating instaed of the smp coating. You will get a much longer lasting product.The paint will not fade over time."
Is fading the only drawback as it is going to be white in color so I don't think fading is an issue?

 

[aar0s]

where i work we sell alot of a product called "Triflex" by Grace. its a synthetic felt thats covers 10 sq to a roll and cost about the same as 10 sq. of 30# felt. the positive side is that you make one trip up the ladder, not five with the felt. the negative is that the stuff gets slick if there is any little bit of moisture or dust on it. over all its a pretty good product, like AMCguy said its real tough to tear.
Ive seen guys do both cap nails and staples on it. If its going to be a while between putting down the felt and putting down the metal you can screw some 1x3 strips down to keep the wind from pulling the felt off. good luck and remember to wear leather gloves when handling the metal, it will cut ya in a hurry!

 

[onewaydave]

scofo I'll relate my experience.

When I did my roof, the contractor put down the Titanium with staples, one almost on every "no staples" phrase in red all over the place or about every 6 inches. Well before the tin went up it rained and leaked worse than if nothing was up there at all. I made him tear it off and replace it with the plasticaps. His loss not mine. Absolutely, positively, without a doubt no staples. Just burn your money instead.

I priced the concealed versus barn tin. The manufacture said the only difference was cosmetics and price. About $10K versus $30K for the metal. Both had a 50 yr warranty. So I went with the barn tin and have enjoyed it.

Marble Falls, Tx shouldn't worry too much about ice/snow damns but up in nothwern KS we do.

I have no dimples! Installer should adjust the screw gun to stop with just slight compression of the washer, not screw it to 40 Ft.Lbs. or whatever.

 

[alexb2000]

No recycling that I know of in Texas, but at least in the DFW area I can get a 30 yd. dumpster for around $350 you'll spend more than that on dump fees, gas, and tire repairs (seems like every other time I go to the dump I pickup a nail).

If price is a concern I would think long and hard about underlayment vs. felt or modified felt. Felt type products are going to be way, way cheaper than underlayment.

Also, regarding the above post about exposed fastener roofing systems. I use them because of the large price difference vs. covered fastener systems on commercial buildings. However, they are take a lot more care to install leak free and they are really difficult to find leaks on (especially when installed over decking). If you are considering this option then make sure and use the fasteners with the metal cup washer built into the fastener. The cup washer keeps the neoprene sealing washer from splitting and being forced out if they get over-torqued.

I agree with the above post about spending the money for a good paint warranty (50 year). In Texas I have seen the cheaper stuff faded and rusting in less than 5 years.

I also assume you've worked out how to address the penetrations (pipes, etc). I use a commercial roof jack and make a cricket using a lot of good sealer like NP-1.

I don't know what your pitch is, but if it's 6/12 or better think about safety. That metal roof will be really slick.

 

[twostory]

I have used "Tri-flex 30" with button cap nails in the past with great results. 6 month exposure and no leaks. Great product for the "weekend builder" process that us DIY people use.

Grace has a new, cheaper product now call "Triflex" Both are available at Home Depot. The cheaper "Triflex" is much thinner than the "Triflex 30". It looks okay, but I have never used the new cheaper Triflex.

While it is true they are slippery when wet, they do not get all wavy like "tar paper" does when it gets wet.