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Do I need weather shield over entire roof if getting solar?

Do I need weather shield over entire roof if getting solar?


  #1  
Old 03-22-24, 08:00 AM
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Do I need weather shield over entire roof if getting solar?

1 out of the 5 roof estimates I've received included weather shield over the entire roof, to help protect against leaks if we have solar installed. The other 4 companies included the more standard 6' (3' in certain areas), and at least one specifically mentioned you shouldn't do the entire roof as it needs to breathe.

Which is correct?

On a separate but related note, on 2,400 sf of roof, what (approximately) would be the extra cost of doing the entire roof vs. just 6'?

Thank you.
 
  #2  
Old 03-22-24, 10:11 AM
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Which is correct?
I'm not sure there is a "correct" way but if it was me I'd certainly be doing the entire roof under the panels if I was given the option. The panel racks install with multiple lag bolts thru the roof. There is always a chance one could leak.

Can't help you with the cost.
 
  #3  
Old 03-22-24, 11:39 AM
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Most modern homes have significant attic ventilation. So, there is no breathing for the roof to do. If money is no object I'd cover the whole roof but only do the solar panel area if you want to keep the cost down, or just the lower edge of the roof and valleys as a budget option.
 
  #4  
Old 03-22-24, 04:43 PM
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Ice and water shield costs in the range of $0.50 to $1.00+ per square foot, depending on location and brand, and that's just for the material; installation would add to that. Since each roll of the material is lapped over the previous row by 4-6" typically, you would use 15% or so more material than the base square footage of your roof.

Putting it on the entire roof isn't a bad idea if you will get solar installed, as long as your attic is well ventilated. It does complicate future re-roofs because the ice and water shield should be removed and replaced upon re-roof (although many corner cutting contractors won't remove it, or will put a new layer over it (which usually voids the warranty on the new material), and in the removal process, sheathing is often damaged, requiring replacement. But a re-roof with solar is already a bigger job, and with luck, you will move and it will be someone else's problem.

[eta:] The extra cost of the material will be offset somewhat because they won't be putting underlayment or felt paper on the roof. It's a lot cheaper than ice and water shield, but it will offset the cost a bit.
 
  #5  
Old 03-28-24, 11:29 AM
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Follow-up question; unrelated to solar, what is the standard (3', 6', something else) for ice shield in the northeast (CT)? Is 3' ok or do I want 6'?

On a separate note, are 6" gutters with 3x4 downspout the thing to get these days, or is 5" with 2x3 just fine? We have a lot of downspouts so it's not as if all rain from the entire roof is going to one section.
 
  #6  
Old 03-28-24, 02:03 PM
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Be aware that if you install solar your next reroof will have an additional expense. My neighbor is having his roof replaced. The solar company wants $14,000 to remove and reinstall the panels.

Try making that up in electric bill savings.
 
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Old 03-28-24, 02:09 PM
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Based on CT codes..... the minimum is 36" of rain shield.
I'd want 6' in place.
 
  #8  
Old 03-28-24, 02:15 PM
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Thank you. When I asked about 6' he said it wasn't necessary due to how he wraps this and that at the edge by the gutter, with this underneath that.... Whatever he said sounded good, but of course was greek to me...

 
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Old 03-28-24, 03:25 PM
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I'm in a cold zone here in NJ.
I have 6' + of ice shield. I consider it insurance.
 
  #10  
Old 03-28-24, 04:05 PM
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Thanks. I'll have to ask him again about this. Does everything else here seem ok though?

remove all roofing to wood deck
3' of grace ice shield wrapping all fascia boards
15 lb tar paper on remainder of roof deck
drip edge - rake edge white aluminum edging
copper chimney and pipe flashing
30 yr architectural shingle (I believe HDZ but I need to confirm)
includes 3 sheets of 1/2 cdx plywood, additional at $70/ea
install cobra ridge vent on all roof peaks

i might have missed copying something down, but any other major items that are missing from the estimate?
 
  #11  
Old 03-28-24, 05:36 PM
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It doesn't look like they are installing drip edge on the eaves, only the rake edges. Instead they are wrapping the ice and water shield over the fascia. This will pretty much guarantee you will have water dripping between the gutters and the fascia. That's how my house used to be and there was always water dripping from behind the gutters. Some places wrap the ice and water shield into the gutters, which solves the problem with water running behind the gutters, but prevents the installation of many types of gutter guards. I think the best approach is to install the drip edge on the eaves with the dropped part of the drip edge spaced about 1/2" away from the fascia. There's a good video on the this old house site showing why this is important.

As to how far the ice and water shield should extend up the roof, it depends on the slope of the roof and how far any overhangs extend. Imagine if you measured 24" from the inside of the exterior wall. Then extend that point straight up to see where it would intersect the roof. Note, it is not 24" measured along the roof slope, but 24" measured horizontally from the inside wall surface. The ice and water shield should extend at least that far onto the roof. One 3' course of ice and water shield might be enough if you have a shallow roof pitch and shallow overhangs, but on many roofs 1 course is not enough.
 
  #12  
Old 03-29-24, 06:09 AM
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Thank you for the info.
 
  #13  
Old 03-29-24, 06:57 AM
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Any thoughts on tar paper vs. synthetic? It's so annoying as literally every quote mentions something different. I've seen:
  • 15# tar paper
  • tar paper
  • Synthetic Underlayment
  • Tiger Paw Roof Deck Protection
  • GAF Felt Buster
  • Roof Underlayment (which I was told is synthetic, but not sure what specifically)

 
  #14  
Old 03-29-24, 02:47 PM
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This is a pretty good summary of the pros and cons, even though it is written by a manufacturer of synthetic.

As mentioned on that page, it's worth checking what the shingle manufacturer recommends/requires. Roofing warranties are pretty much worthless, but no point in giving manufacturer an easy out.
 
 

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