Homeowner Re-roofing questions


#1

Hello,

I am a homeowner and is re-roofing my home. This is my first time doing a roof.

I have and still am researching about re-roofing and found your website. Thank you for the information on this site and your willingness to share.

Background:

  • Property is in San Jose, CA (Bay Area) so no snow but home has frost near eaves. Some neighbor homes have frost too.
  • It has a hip roof that is a basic U-shape with two gables, 4/12 pitch (but not all the pitch are the same; some rafters I measure comes out about 4.5/12 pitch).
  • Roof area is about 33 squares.
  • There are box vents inside the U-shape as the outside of the U-shape faces the streets the home is on a corner lot.
  • Open eave with exhaust box vents and intake eave vents.
  • Current roof is asphalt 3-tab shingles over wood shake or wood shingles, under the wood shingles are skip sheating.

I am doing the roof a few sections at a time. I wanted to re-roof one section at a time but I couldn’t figure out how to do that at the valleys. So I have started on the inside of the U-shape where there is a valley.

I am removing the old roof, fascia, repair rafter tails, repair termite damage, vacuum out old cellulose insulation, disinfect and deordorize because of rodent damage, use termite foam where there are active drywood termites, treat attic with Bora Care as a termite preventative, air seal the open part of attic, fix ducting if needed, reroute exhaust vents if needed, (add one or two ridgid Velux sun tunnels), put down new fiberglass insulation batts, replace old and add new eave vents, put down 1/2 in OSB radiant barrier.

At the end of the work day, I tarped the areas and weighed them down with sand bags.

I have not put up new fascia and will add gutters all around. Currently there are gutters only on part of the eaves.

I have three sections of the roof that are opened, three sections has OSB put down, working on nailing other two sections now.

I have many questions but let me start with these:

  1. I am using half-dormer vents. I have calculated the ventilation using the 150 rule. Can I install half-dormer vents on both sides of the hip roof to increase air exhaust? If I do, will that cause a short circuit in the venting?
  2. Some gaps between the OSB sheating are up to 1/2 in wide (one gap is up to 5/8" wide). Will this be a problem? Should I cover the wide gaps with a 6 in strip of peel and stick? Your advice?
  3. For drip edge with kickout, would you use 110 deg or the regular 90 deg? which bend angle is better? I am planning to use 3" x 3" (or 3x2) with kickout.
  4. I renailed the skip sheating with one nail over rafters because some of them were loose with 8D common nails by hand and with 2 3/8" x .113" smooth sank if using framing gun. I nailed the 1/2 " (15/32) radiant barrier with 12D sinkers if by hand and with 3" x .131" if using framing gun. Is what I am doing here correct? Do I need to change anything here?

If this is better done in private messages, let me know and I can send you my email address.

Thank you in advance for your time and help.


#2

You would treat the dormer vents the same as the box type vents, they are functionally the same.

The small gaps you currently have in your osb sheeting will be fine, try to keep them smaller if you can.

The 110 deg kickout is the one you want in most cases.

I usually use 16d when sheeting over skip sheathing but 12d should be sufficient.

What type of roof do you intend to install?


#3

Thank you, Axiom, for the information.

With the current roof, there are box vents on both sides of a hip. In my search, someone mentioned that when there is wind, with vents on both sides cause a short circuit. I need to increase the exhaust vents and the only way to do that is to add dormers to both sides.

I was leaning towards 110 degree with kickout but then I saw a photo somewhere that with the 90 deg bend, it angles in so water would less likely to wick up. I called one roofing supply store and the rep said both would work fine. I wanted to get the pros advice.

As for the gaps in my osb sheeting, I was trying to get the 1/8 in gap all around. But I ended up with some large gaps. Thank you for letting me know that those gaps are ok but keep them smaller.

I am going to install Landmark shingles. This is from reading in this forum that many roofers here like Landmark shingles better. I was deciding between OC Duration and Landmark.

Thank you again for your help.


#4

Sounds like you are on the right track. Must be nice to be in CA where you can do so much work with your roof torn off, weather never cooperates like that in the north east.

I would not worry about 1/2 - 5/8 gaps in your plywood if it’s installed over skip sheathing. 12d should be fine, that is what I normally use. When deecking over skip sheathing we normally tack the sheet then snap vertical and horizontal lines to insure you are nailing through the lath into the rafters. If you nail over the gaps the nails either blow through or do not hold good.

Landmark is a good shingle. Depending on pricing in your region landmark pro might not be much more, here it is only a 6$ per square difference.


#5

If you know you have an over sized gap in the sheeting, then what i do is i use a yellow or white crayon and draw over the underlayment in that spot letting me know when i shingle it to drop or raise my roofing nails in that spot so i dont shoot into an air space.


#6

I try not to install vents across from each other, but in some circumstances it’s unavoidable. K
5/8 is a little much but no big deal. Make sure your nails hit the plywood and 1 row every 16 being a little high nailed will be fine.


#7

@MPA
Yes weather is good for me to work on the roof and in the attic. It still gets hot in the attic even with the roof open so I tend to take breaks and drink cold water and juice.

Thanks for the tip about snapping vertical and horizontal lines. I only snapped vertical lines the first time but the second time, I snapped both vertical and horizontal lines. I still missed a few times and went into the attic to pop the nails out and re-nail.

I will check on the price of landmark pro in my area and see if we want to upgrade.


#8

@roof_lover
Thanks for the good tip of marking the area over the underlayment so I don’t nail into air space.

Do you think I should cover the large gaps with 6 in of peel and stick and then synthetic underlayment over that?


#9

@patchap
Thanks for replying.

If I don’t add vents across from each other, then I don’t have enough exhaust ventilation.

I may have to add two or three across from each other.


#10

Thank you all for replying and giving me tips and advice.

I have one more section of roof decking to nail down (out of the three sections that I am working on).

I have more questions so is it better to ask in this post or start a new post.


#11

I wouldn’t waste my time covering those gaps with peal and stick. Just make them and make sure not to nail into them when installing your shingles. Peal and stick offers no benefit in that situation whatsoever.


#12

Thank you all for your help and advice.

I completed nailing the third section of the roof today.

My next step is to install the 1 x fascia boards.

Do I need to prime and paint the rafter tails first?
Do I use galvanized nails or exterior screws and what size? finishing nails?

Thank you in advance for your help.


#13

We prime all sides and paint anything exposed to the weather, espically new wood. The lumber today, no matter what species, is from younger growth trees and is softer than years ago. Use a good alkyild or oil based of primer. For facia I normally prime once and paint once before installing and put a second coat on once it is installed.

For fascia I prefer a galvanized nail with a head. Maze of cedar nails or work great. They are skinny and ring shanked So they don’t split the wood and hold good. If you are installing gutters I normally throw some deck screws in the top of the facia where they will be covered by the gutter.


#14

@MPA
Thanks for the tips.

Yes, I will be installing gutters all around but that will be at the tail end of the roofing project.

So prime and paint, then use ring shanked galvanized nails and/or deck screws.

What length of screws or nails do you use for 1 x boards? 2" or 2 1/2" or longer?


#15

I normally use 3" if I am going to screw it, that will give you 2 1/4 into the rafters tail of using 3/4 fasia


#16

I really appreciate your help and suggestions. I am learning a lot from this site, youtube, other websites, books, etc. But nothing is better than asking experienced roofing pros.

I have received a couple of quotes back from suppliers and still waiting for a few more.

I have some questions for the next steps in my re-roofing project.

I will be using Swiftstart starter shingles and Shadow Ridge caps to get the upgrade wind warranty.

  1. Diamond Deck vs GAF Tigerpaw and WinterGuard vs Owen Corning Winterlock: Do you see any problems with me using Tigerpaw and OC Winterlock? These are available at the box store and priced lower than Certainteed products.

I have an email to Certainteed to see if I use non-Certainteed products, will that affect the shingle warranty.

  1. Nails: I am installing 15/32 radiant barrier OSB. I would prefer not to have lots of nails poking through the OSB in the attic. Would 7/8 in or 1 in hot dipped galvanized shank coil nails work and to code?

    1.5 in hot dipped galvanized shank coil nails for the hip and ridge caps?

  2. Do I use the same nails that I use for the shingles for the drip edge and W-valley metal?

  3. Cap nails: 1/2 in or 3/4 in plastic capped nails hot dipped galvanized ring shank? (not even sure if they make 1/2 plastic capped nails). One quote states that the capped nail is smooth and not ring shank.

Thank you very much for your time.


#17

Your nails need to penetrate the deck per manafactures specs. Espically with osb if they don’t break through they will back out. 1.25" minimum nails with 15/32 deck. If using loose plastic caps you won’t have fingers left if trying to use I ones that short.


#18

Shouldn’t be an issue using non certainteed products for the standard warranty. They will probably state that they won’t be responsible for issues related to the underlayment.
We use generic Underlayment every day, as do many roofers.


#19

I think you just need 4 of their products to register the warranty.


#20

@MPA

My fingers are small so 7/8 in or 1 in plastic nails should be ok for me.

Do these cap nails have to be galvanized ring shank?