Hello,

So, my roof patching and subsequent need to fix the leak that I introduced is tilting me toward re-roofing the entire garage.
When (if) I take on the re-roof, I'm thinking of adding a continuous ridge vent--even though the garage is not insulated. The garage gets incredibly hot in the summer. The eaves are vented, so I'm hoping that a ridge vent will allow much of that hot air to escape. Is that a particularly bad idea for any reason?

Also, I'm wondering if it is possible to re-roof in "stripes". What I mean is, unconventionally, start at the bottom (at the eave) and tear off the bottom 4 feet of the old roofing. Then install the roofing felt. Then install the first 6 courses of shingles. After that, I'd tear off the next 4 feet of the old roofing, install felt and 6 courses of shingles. I'd work my way up to the ridge like that. Oh, and when I get to my problem area, where roof-lines from the house and addition converge and dump runoff onto the garage roof, I'd switch to ice&water shield (vs. felt).

Why would I ever want to re-roof in that way? Because, I'm mostly a weekend DIY'r. It is very likely that I wouldn't be able to complete one side of my roof in a single weekend, so I don't want to leave bare sheathing exposed for, possibly, 6 days.

I realize that I'd be removing old roofing higher up on the roof than the new roofing that I'd be installing, so I'd need to be careful not to damage the new roofing. I was thinking that I'd cover the newly laid roofing with plywood to form a chute that I'd use to slide the stuff I tear off from the roof?

What do you think? Totally wack or merely goofy?

Thanks in advance.

 

Adding vents in the roof doesn't really help unless you also create open area down low for cool air to enter. In houses these are usually soffit vents but you can also put vents in the walls or wherever else you want.

Personally though I don't like ridge vents. Ones with good airflow can allow rain to blow up into them. Some have an open mesh to help prevent wind from blowing in which also really inhibits airflow out. I'm more a gable vent or mushroom vent kind of person as I've very rarely had trouble with them.

Yes, you can roof in strips like you mentioned. I would purchase all your shingles needed for the entire roof. They will likely be delivered on a pallet. Separate that pallet into three or four piles. Then when working on the roof alternate grabbing a bundle from each pile. You are trying to randomize the singles so a pattern doesn't appear as shingles can vary slightly in color throughout a batch.

 

Thanks @Pilot Dane. I like your suggestion regarding randomizing the bundles of shingles.
I do have ventilation from the soffits. I only have one gable end that I could install a vent into, since the other gable end is shared with the sidewall of the house. What do you think of the "Whirlybird" vents?

 

Assume you are going to do a strip and re-roof. You can't re-roof a valley one side at a time since the shingles on at least one side must be attached to both sides of the valley whether the shingles are laid with a seam or.seamless. Strip the 2 sides forming the valley to their peaks. Have a tarp(s) big enough to cover the unfinished portion over the peaks.Good luck.

 

Yes it's a goofy idea. Tear off the roof and get it dried in with your felt and ice and water shield. Don't know how big that side of the house is but it should be no problem to do that in a day. I do roofs all the time by myself and it is no problem if you keep after it. If you need to do it in strips, your strips are vertical, not horizontal... and you just paper temporarily over the seam... cut it back when you are ready to continue tearing off.

So if your roof is 50 feet long, 14 feet high, do 25' one day, get it felted... and do the other 25' the next.

When it comes time to felt, proper valley detailing with ice and water shield has to be done all at once... you can't be piecing it together like a patchwork quilt. IMO that's probably the biggest reason why it leaked last time.

On roofs with 4:12 or less, the felt should be lapped 19". Says so right in your shingle instructions i bet. Same for your ice and water where slopes change... like where your wall flashing ice and water needs to extend way up the roof so your valley ice and water can shed on top of it. And roofs should not leak once you have them felted / papered / dried in. Don't worry about the shingles. When you do shingle, keep your nails out of the valleys! And use tarps if you need to protect a partially shingled area.

And get all your shingles from the same lot number for Petes sake. It's almost always printed right on the label.

Ridge vent is a good idea everywhere. You don't need any other kind.
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Thanks @beelzebob & @XSleeper
You're right, I wouldn't try to do the valley piecemeal, just the large flat (albeit sloped) surface.
@XSleeper, it's interesting that you'd recommend working in vertical sections. I was thinking that, if I worked across the horizontal, I could shingle full courses and maintain the proper staggering of seams for the shingles. I can see how the vertical approach would work for the felt and ice&water foundation. But, I think you're saying that I can relax once the entire surface is covered with felt and ices&water, then, if the installation of the shingles needs to be broken up over a few days, it's not a big deal. True?
And, you are not concerned with driven rain getting under a ridge vent.

Thanks again.

 

That's correct. Once its all dried in, shingle at your own pace.

Millions of houses have ridge vent. Somehow wind driven rain does not get in... must be magic. Follow the mfg's instructions.

 

As I was heading out to work this morning, I looked up at the underside of the ridge of my garage--thinking about the work ahead to install the ridge vent. I hadn't noticed or thought about it before, but there is no ridge beam nor ridge board up there. There are just 24" on center trusses with a particle board sheathing roof deck nailed into them.

Is that odd?

 

No, the truss roof on my house is built that way. You likely have 3/4" roof sheeting to span the distance. And, a roof like that is good if you want to install a ridge vent as there is no ridge beam in the way.

 

Your roof trusses may be spaced 24 inches on center down at eaves level but without a ridge board what keeps the tops of the trusses spaced evenly at 24 inches on center?

Scratch the above; it does not affect the performance of the ridge vent.

Without a ridge board, the lengthwise slot cut along the roof peak for the ridge vent can be narrower, say 1-1/2 inches wide at the underside surface of the roof sheathing..

 

Better not be particle board. OSB yes.

 

Thanks @Pilot Dane, @AllanJ, and @XSleeper for your ideas.

I'm now thinking about why I expect the tear-off to be so time consuming. I've replaced shingles on other areas of the roof and it was a total PITA to remove shingles where the roofers used whatever kind of ice&water shield they used. It's sticky on both sides so the shingles are fully adhered to them. That sticky stuff covers the bottom, maybe 6 ft, of the roof (by the eaves). In the past, I've had to use trowels and heat gun to remove the shingles. It's a slow go.

 

When you strip a roof, you go down to the sheathing. Who cares if the ice/water protection strips come off with/without the shingles?

 

The ice&water does not want to come off, because it's super stuck to the sheathing.
The shingles don't want to come off, because they're super stuck to the ice&water.

 

Dont worry, i know what you mean. Might be easier to just cut through the sheathing and shingles with a skilsaw, pull off the sheathing and replace it.

The new ice and water will bond best to a clean smooth surface. Replacing the sheathing is the fastest way to do that.

 

I would stay away from ridge vents. Once you get past all the manufacturer baloney and the installer baloney you will find that most do not work well. I had ones with internal baffles installed and they choked the living life out of my ventilation. One guy who had it done was sick and tired of the high heat. He finally bought two turbines and started cutting the first hole. When he removed the hole, a blast of hot air over took him from that hole he just cut. After a few minutes the temperature dropped 40 degrees in his attic. Ya - for the most part they don't work well if at all.

 

Sorry you had a bad experience with a ridge vent, my whole neighborhood is full of them and they work well.