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New Roof Install- Install Mounts Now or Later?

JeepDaddy

Solar Enthusiast
Joined
Feb 1, 2021
Messages
257
Location
Kent, WA
I'm having a new roof installed on my house this year. I do not have immediate plans for residential solar. Because.....Seattle.....rain.....clouds.....you know. Eventually solar pricing will come down where it makes economic sense to install solar in my area. I have a perfect roof for it.

It's a time to consider installing mounts with the roof. Is there an advantage to installing during the roof replacement vs waiting until later?
 
Well, it depends on the type of roof and the material used such as Tin or Asphalt Shingle.
Not all roofing materials are good under solar panels, roofers don't know this UNLESS they do solar systems too and even then, I would not bet on it.

A Light Coloured Tin roof will reflect sunlight & heat which helps a few ways, by keeping more heat out in general because of the colour, reflecting the light spectrum can help if you chose to use Bi-Facial panels (more watts per sq foot) and of course being Tin if properly installed can last 50 years or more. Standing Seam mounts for solar are available as well as other mounting systems for the different types of metal roof.

Regardless of roofing type, you need to ensure there is support for any mounting system to bolt into. It may require sleepers installed under the sheathing between the rafters where the rails will be attached. Commonly 2x6 sleepers affixed between the rafters does the trick nicely.
BUT this s dependent on roof type (structure) roofing material used and what type of mounting system you will use relative to panel type (Bi-Facial or Not).

Seattle is not that bad, as you furtlle around the area, look at roofs & spot ground mounts etc, you will see there is a lot of solar in place and more going up. You should not under estimate the potentials.

Two quick snapshots of info for you,
Source: http://www.solarelectricityhandbook.com/solar-calculator.html

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Thanks for the thoughtful reply Steve_S. I hadn't thought about sleeper studs. That's a good idea. The roof will be asphalt shingles.

Last winter we had an 80 day streak without a sunny day. That's why I don't think we are economically viable right now. Your solar snapshots are interesting. I will be keeping an eye on panel pricing. I just thought it was worth considering installing just mounts right now if it saves money. If there is not a cost advantage installing mounts during the re-roof, I will wait.
 
It is common to install stand-offs through asphalt shingles. They can be curled up to slip a bracket under, but maybe installer won't do that. I don't like the idea of goop as the only seal, prefer overlapping components or flashing that stands up and seals around a pipe.

In my area, PV mounts no higher than 18" and no more than 40 pounds per support don't require mechanical permit.
Presumably lag screwed into sheathing is considered sufficient. High wind areas could be different.
If re-roofing and planning on PV, I would lag screw standoffs into rafters and use flashing on them overlapping shingles.
Probably overlap standoff bases with tar paper and/or seal with sticky rubber sheets.

Location of panels and therefore mounts varies with revision of building codes. Not easy to plan for the future and not have things change on you.
Maybe put in some amount of grid-tie PV at the time. Maybe that grandfathers the configuration, maybe not (utility might want to see new permit for higher wattage export in the future.)

Solar is already so low it makes economic sense it it ever will.
PV panels and inverters are about $0.50/watt. Other costs like mounting hardware and electrical stuff are starting to dominate. Using quality materials and DIY labor, total cost $1.00/watt. In my location with 5 hours average sun per day, PV generated power would cost $0.05/kWh amortized over 10 years. Maybe replace an inverter at that point. Cost $0.03/kWh amortized over 20 years.
Scaled (or re-analyzed) for your location/sunshine and equipment choices, how does it compare to your utility rates?
(rules forcing you on a different rate schedule, or buy high/sell low rather than net metering, may change the game.)
 
Asphalt Shingles do not do very well under solar panels.
You would likely gain more energy savings if you installed a Cool Roof system that prevents thermal transfer to/from the roof & Attic. This is a Big Win in Summer as it keeps the house considerably cooler and in winter it prevents the cold from "sucking" the heat out through the roof.

I built my home with this type of system and while I was a bit hesitant at first I am SO GLAD I did, it makes such a huge difference in the comfort & energy demands. My place has Cathedral Ceilings and a Loft, it never gets more than 2 degrees warmer upstairs than on the main floor (summer or winter).

The company shown below which originated the information is gone now, I suspect a Victim of Covid.
ATTACHED two PDF's from a website archive. There are other companies that do this and it is also written up on GreenBuilding Advisor and elsewhere. I prefer this companies explanation & overview.


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Attachments

  • Cool Roof Design for Hot Texas Climate _ Houston Cool Metal Roofs PART-1.pdf
    853.7 KB · Views: 15
  • The Cool Roof_ A Risk-Free, Tax-Free, Inflation-Proof Investment _ Houston Cool Metal Roofs.pdf
    606.9 KB · Views: 7
Asphalt Shingles do not do very well under solar panels.
Yes that is a problem and most houses are asphalt shingles.

What I did is have Radiant Barrier installed in the attic. I also added more blown in insulation but that does not affect the panels.

This was another house we bought and brand new so replacing the roof to a cool roof system would not be cost affective, but would love to do later when this roof needs to be replaced if we are still living here and not renting this one also and bought another one.

The best would be a cool roof system with a standing seam metal roof.

Our rental house that does not have solar we just installed a new roof and they now have avab Energy Star asphalt shingles. We had the CertainTeed Energy Star Shingles installed.






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Well, I have seen the results of the certainteed shingles, good marketing but not much else. I go by Canadian CMHC Tests and evaluations, I don't fall for marketing.
Cool Roof system as I showed above can be easily retrofitted when a new roof is required.
Standing Seam is by far the best way to go with modern metal roofing. Heavier Galvanised Steel Shingles (similar to what was used 100+ years ago) are also making a comeback but they are far from cheap but they are 100 year roofs, so....

One thing many won't tell about, if doing a metal roof, is to order the "tin" with a Condenstop. This is a sound deadener and prevents condensation underneath the metal. There are different "trade names" for it.
 
In Florida insurance companies charge extra if your asphalt shingles are more than 10 years old. I put new shingles on 2 years ago and I am installing solar panels now. So, there is a good chance I will have to remove the solar panels in 8 years to replace the shingles.
 
In Florida insurance companies charge extra if your asphalt shingles are more than 10 years old. I put new shingles on 2 years ago and I am installing solar panels now. So, there is a good chance I will have to remove the solar panels in 8 years to replace the shingles.
Shingles last alot longer that 10 years and we have never had our insurance change do to the age of the shingles. We live in Florida.

We bought the house we are renting in 2005. Just this year we replaced the roof and only due to storm damage. The Insurance has been the same since we bought it. Matter of fact what you are saying I should be paying less now since we have a new roof system...

Note that house new had a low grade three tab roof and yes they do not last too long but I would never own a house with a three tab roof anymore.

These new roof systems installed properly and by an installer that is certified by the maker have up to 50 year warranty.

Both our rental and the new home have 50 year warranties on the roof systems.

I guess it just depends on what you put on your roof?




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Well, I have seen the results of the certainteed shingles, good marketing but not much else. I go by Canadian CMHC Tests and evaluations, I don't fall for marketing.
Cool Roof system as I showed above can be easily retrofitted when a new roof is required.
Standing Seam is by far the best way to go with modern metal roofing. Heavier Galvanised Steel Shingles (similar to what was used 100+ years ago) are also making a comeback but they are far from cheap but they are 100 year roofs, so....

One thing many won't tell about, if doing a metal roof, is to order the "tin" with a Condenstop. This is a sound deadener and prevents condensation underneath the metal. There are different "trade names" for it.
Well They do help and I have first hand look at the difference with my Thermal Camera. I guess it depends where you live. They would make no since to have in Canada... But in Florida every bit of heat you can reflect from going into the attic helps.

The Radiant Barrier will help alot more than those shingles and why I installed that in our primary home, but again does you no good in Canada.

We are in Florida and have some crazy hot weather. :)





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Shingles last alot longer that 10 years and we have never had our insurance change do to the age of the shingles. We live in Florida.

These new roof systems installed properly and by an installer that is certified by the maker have up to 50 year warranty.

Both our rental and the new home have 50 year warranties on the roof systems.

I guess it just depends on what you put on your roof?
When I bought my house the inspector wouldn't buy off the roof because it was 10 years old. The sellers had to replace it.
I heard insurance companies charge extra for roofs over 10 years old. I have not verified that.

My roof has the latest expensive shingles that were installed by the highest rated installer in town. I will not take my shingles off until they need to be replaced.

I still think metal roof is a better choice for solar panels
 
Ummm... -30°C/-22°F on a cold winter day. +30/+40°C -/- 86°F/104°F in summer with 80% Humidity. Most common where I am.
Your statement "does no good in Canada" is malarkey.
 
I still think metal roof is a better choice for solar panels

!00% Agree...

But you best bet is not to install the solar on the roof at all and if you have the land put them on the ground.

That's what we will be doing next time. This solar system was just for fun.



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Ummm... -30°C/-22°F on a cold winter day. +30/+40°C -/- 86°F/104°F in summer with 80% Humidity. Most common where I am.
Your statement "does no good in Canada" is malarkey.
LOL When I think Canada I think just cold... I know I would not want to live up there. My wife won't ever moved back to NH where she grew up.



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We hear people are fleeing the Bay Area (although all articles are actually ads, so there is an ulterior motive.)
The weather is pretty nice here in San Jose.
A modest ranch house can be bought for under $1.5 million.


In the right location, when the "Big One" hits, you'll have a split-level.

 
And I remember when I was shocked to see a house like that listed here for $375k. That was 20 years ago at peak of Dot-Com boom, and McMansions were $800k.

A couple sales of less extravagant homes in my neighborhood were around $1.4M and empty lots were about $600k (extravagant homes were offered between $2M and $3M, but no takers so the developing owners moved in). I was happy with my $600k purchase, which included a pool, biggest in the neighborhood and bigger than my house. We've seen $2M to $3M sales in the past couple years. These are faux executive homes with "stone" walls consisting of painted concrete over cinderblock, exterior molding around windows is stucco over foam, no executives in sight. Self-respecting tech executives live on Pierce Road in Saratoga, where prices have one more decimal place.

Around 2003, 1600sf 2-story new crackerjack box homes 10' apart on the flatland were selling for $950k. An older home on the hill next to me, 3000sf on half an acre with view of the valley, sold for $850k. The demographic that was buying put more value on "new".

I remember visiting Florida in the mid 90's. Some houses were $35k if I remember correctly. Or maybe I should say the dollar was worth much more.

Salaries are higher here, average engineering salary 50% higher than some other states recruiters have contacted me about. Unfortunately we have the same tiered federal tax rate schedules as you, and deduction of state income tax (about 9%) and property tax (about $15,000 for that ranch house) are capped. Only saving grace is we go past the limit on Social Security tax, so it drops off for our last dollars of income.
 
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I bought a house in Redondo Beach in 1990 for $250,000 and that seemed extreme at the time.
It is worth over one million now. I miss California but it is easier to retire in FL. I'd have to work if I lived in CA. :cry:
 
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