House is 20 something years old. I know a new roof is on the horizon.

I see and hear of some slapping another layer of shingles on, leaving the old ones in place..

Seems like a hap hazard way of doing chit...

So, of course, my question is, add another layer or tear it all off and start over ?

Any helpful ideas would sure be appreciated ! Also any input on the felt/paper would be great.

If you can afford it, I’d probably lean toward a tear off. A bunch of houses have two layers though around here.

A lot depends on roof construction.

As long as there is only one layer already, unless your roof has structural or water damage issues I wouldn't have a problem adding another layer.
But never more than two layers, and only if the framing will support the added weight.

Metal

I'll have to look.. I know the walls are on 16'' centers also 2x6 outside walls.. Can't remember the roof right off..

If you are contracting it out, a lot of roofers will not overlay and if they do they offer no guarantee.

Tear it off, inspect the sheathing, then apply the appropriate underlayment like Ice-n-Water barrier and get a guarantee.

Some jurisdictions require complete tear off

Since it's probably the biggest investment a your life so far, you should go as cheap as possible when protecting it.

LOL

Best to tear it off. Get to bare wood, make an assessment of any questionable decking issues.

New from the decking up.

Manufactures I believe will not warranty the new roof is it doubled. Many little events can occur namely, old nails working up from beneath and cutting thru thr new shingle

Be diligent about getting all of the old roofing nails out of the deck. Go back and rehammer down the decking/plywood nails. Add a few new ones too

Tear off is the best. While your gathering information on a new roof, read up on continuous ridge vent. Put a few on and they work great. They make different sizes. Most places stock the minimal coverage type but you can order the larger type for more lap over the ridge.

^^^^^

Does a continuous ridge vent work well with 4’ of snow over it?
😂

I seen the guy was from Texas, does he get 4 feet of snow there?? In all honesty I would have to read up on the snow issue.

It was TIC.
I don’t think I’d install one here.

You will get half the life, maybe, out of that second layer. extra heat on the original layer will cause the tabs to curl, and they will curl your new shingles along with them.

Just read ridge vents and snow from Fine Homebuilding. Google it! They have a good outlook on using it.

Perfect, to the decking it is...

I live way the hell out in the country. Even so, guess it's been awhile since I've seen two layers..

No or very little snow, but the area did just go though a lot of wind and hail.. Lots of stuff destroyed...

Heck no! Insurance companies allow 2 or 3 layers.
If you go from composition shingles to metal, your home insurance company will reduce your payments!
A metal roof is cheaper than shingles.
Metal will last 50 years or more and is literally maintenance free!

The one downside to a metal roof is you'll have to sign a cosmetic rider. If a hail storm hits your metal roof and dents the heck out of it, the insurance company won't replace it unless the hail actually breaks the metal.

No way in hell I’d do shingles again

Pat,

you could just build a new house ya know.

Humor aside, I think you're on the right track following some of these guys' advice. Would love to replace ours with metal when it finally goes. 18 years old now and starting to show some wear and tear. Being retired, we'll probably do asphalt shingles again and let new owners live with them after we die and no longer own the place.

EB, I'd probably be all over a metal roof and will definitely look into it..

My reluctance lies in the fact I'm 70 years old, a comp roof will probably outlast me..

As stated, tear off, check for sound wood, use modern underlayment, proper nail spacing per shingle, new pipe flashing boots, ridge vent with matching or proper soffit vent sq ft. , T drip rail flashing, if moss is an issue place zinc strips at top both sides.
With one layer and proper venting the house will be noticeably comfortable. As mentioned the roof will last longer.
Some of this is required by code in many areas, a roof done right looks good from day one.
There is often quite a difference on warranty, life and wind rating with specific nail count, staples are not as good here in the wind.

The only way I would go metal, which I like, is heavy gauge standing seam over plywood sheathing.

Yes

Slum for the win.

I would tear off asphalt shingles and reroof with standing seam metal roof. It will be trouble free for many years. They look very good also.

Makes no sense!?

1. Metal roof is cheaper than composite shingles
2. Home owners insurance savings

Whether you outlast a metal roof or not, it's still money in your pocket.

Metal was not cheaper for me last year. Not even close.

Avoid vinyl/plastic pipe flashing with rubber boots. The vinyl bows with heat and pulls nails over time, and the sun will deteriorate the rubber boots. Then you have leaks. Choose your roofer wisely.

I'd heard that metal was considerably more expensive than shingles thus my comment about price and longevity .

Thanks GL, I'm making notes of all this information..

I just had my house re-shingled on Saturday due to hail last fall.

$17k !!

It wasn't big hail but I called the adjuster anyway. It got approved to be re-done, thank God! I was due in a year or two anyway.

Reroofed our home in 2015? Ten years ago?
Our roof has no hips or valley's.
If we had used colored metal, it would have cost $2K more. We went with galvanized and saved.
The roofer we used dealt in metal roofs only.
AND........ we shaved several bucks off our homeowners policy premiums, too!

How did your price compare to shingled?

I had mine done in shingles (full tear off, replaced 5 sheets of plywood under) for 225 a square with shingles. Metal was quoted at 675 a square. Last year. Metal was more expensive from a materials and labor perspective.

Metal roofs can last 40-70 years, depending on the material. Traditional asphalt roofing materials have an estimated life expectancy of roughly 12-20 years.

So, a metal roof lasts 3× longer than shingles.
You'll pay for 2 to 3 more shingle roofs before a metal roof goes bad.
A metal roof can add as much a 6% to the value of your home.
A hail storm that won't faze a metal roof will ruin a composite roof.
We didn't use the "standing seam" metal. Three rib standard metal roofing from Metal Mart in Wichita Falls, TX.
Used it on the outside of the house too. No painting a house for me! 😉

Interesting as the metal roof estimates came back at 2.5-3x the cost for shingles. No savings for me. The old roof on here was 35 years old. The old shingle roof on our hunting camp was well over 50 (was torn off a house and we "reused" them another 35 years). Shingles last longer than most give credit for.

Hail storms aren't a major issue here, we get some good wind but even that - in the grand scheme, isn't much.

I haven't seen anyone here mention that current "Architectural" asphalt shingles are superior to the old 3 tab thats probably being replaced, better looking too.

Oh boy galvanized colored metal

Bet that looks delicious


maybe on a barn

ARRRRRRRRRGGGGGGGGGGHHHHHHHHHHHHH

Goes without saying nowadays

3 tabs are garbage. Most only have a rating of about 39mph.

Most dimensional arch/dragon tooth oakridge2 from O/C, Elks from gaf, heritage from Tamko are much heavier and will rate up into the 60mph range.

I have Certainteed Shangles lifetime on mine, rated for 110, a coastal rating. But they are not cheap.
I do have metal on all of my decks and sunroom.

Old shingles are a great way to line a runoff ditch.

Metal roofs can also sweat on the bottom . If you have metal put on , strip the roof ,put a vapore barrier down and run i" X 2" runners to fasten the steel to . Some metal roofs might last 50 years ,but not the cheap ones.

Not a problem, you'll never have to look at it. 😉

Might hav ta paint that schit 1 day

I hope you at least got Galvalume

Not a problem, you'll never have to look at it. 😉
I live in "Tornado Alley". We are under a tornado watch right now.
We get hail quite often. 50+ mph winds aren't uncommon.
Seventy mph winds and a blizzard left us with 6 foot drifts and ripped off shingles. Roofer couldn't get to us. I'm out there in gale force winds, scrounging ripped off shingles to patch as best possible!
Tin was a blessing for us!

Yes, they have 35 year shingles. They still won't last as long as a metal roof.
In today's economy and inflation, what is that 35 year shingle gonna cost in 35 years?

Mine are lifetime/50 year (Carriage House)

435 lbs per square

Martin, Strummer

Here is some ribbed galvalume we upgraded one of our bldgs with.

It had to match the old 5V galv

Full tear off. Around here i go twice the recommended height of ice and water especially with lower pitched roofs. I've used malarkey on my last 4 roofs. Used to use Certainteed they worked too.

Bb

if you have a smaller house and use the screw down metal you can get close to shingles but no way will you get standing seem close it seems to be three times the price of shingles around here

I generally prefer the Synthetic underlayment finding it stays down better in the wind during install.
Naturally it installs horizontal like roofing and thought that was simple to understand. I showed a guy who asked about it, showed him the roll and button fasteners. Few months later he stops to tell me he figured a faster way, vertically from gutter to gutter over the ridge. Still laughing.

That's hilarious.

I'll be dead- why would I GAF?

The country won't last 35 years, I don't care about the shingles.

The reason you see so many asphalt shingle roofs is the cost . Cheaper than everything else.

If I last another 35 years, I'll be 108 years old.
Possible, but not probable!
I'm not concerned about the lifespan of the metal or my imminent demise. I'm concerned about the durability and efficiency of a metal roof while I AM here!
Our metal roof will outlast both my wife and me.....but in the meantime, we have left a legacy to our children who won't have to deal with a leaky roof for another 40 to 50 years.
If a tornado should destroy the house in the meantime, a metal roof is a moot point!
"IF" that should happen while we (the wife and me) are still around, I'm sure we will replace it with another metal roof!

My wife and me literally built our home with our own blood, sweat, tears and hands.
Termites may chew it down, but our home won't suffer catastrophic failure due to unseen roof leaks!

"... The country won't last 35 years, I don't care about the shingles. ..."

So the structure you spent thousands and thousands of dollars on has no value to your heirs? ....or you just don't GAF about your children and grandchildren?

P.S. I'll be 74 this year. I sprout pecans and plant pecan trees every year. Somebody, at some point, should have a pecan crop deluxe. If not me, maybe my kids!
At least I've left something of value behind!