Interesting thing I'd never really considered

The latest “nails through the decking” had me wondering…

We see older houses with plank type decking & often have to do repairs to slats because of fractures as a result of the sap drying out & knots, however this isn’t really a concern with ‘true’ ply or OSB.

Since ply or OSB sheeting hasn’t really been the standard for more than about 30 years @ the most, my question is this:

Assuming that a roof deck has been fully stripped of felt on EVERY re-roofing, which we all know is very unlikely unless it’s required by code & completely inspected for this, @ What point would you consider it to have too many nails & the integrity of the deck to not properly hold any new nails?

Also, how many of y’all pull all & I do mean ALL of the old roofing nails & roofing staples? I know that my crew prefers to bang 'em flat whereas I’m more of a “pull what won’t require destroying the deck” kinda guy.

I guess that it’s going to be an issue for roofers in 100 years as to whether or not the plywood has been overshot with nails & not in our lifetimes (unless medical science has found a way to keep us alive for a lot longer than we already are).

I think all of the trades through the years have to deal with the changes in the codes. Do you think a roofer thought years ago when they put on the 1X6s that we would have to resheet them? You’re ahead of your time RHR !!!
I think the changes will happen forever as things improve. But what you say about the sheeting is probably nothing we will have to worry about in our roofing careers.

FWIW, I make the guys pull all the nails on the tearoffs. Usually our tearoff tools get them all, but sometimes we ned to go back and get the loners. I do let them pound in the little nails on the cedar tearoffs though.

As far as busting strip decking goes,handnailing shingles is by far worse on breakage.Nailguns seem to shoot the nail in with ease Vs.pounding on the decking with a roofing hatchet.

Since most shingles are started off at the same edge everytime a house is roofed ,the nails will be close to the same exact pattern .Eventually it will cause the plywood to weaken and a different pattern will have to be used.More nails going back in the same holes means more nails backing through the shingles.

I always pull the nails sticking up and if they have roofing materials under them.I have found that some of the nails that are driven back down tend to back out through the shingle.Even decking nails that are sticking up need to be pulled instead of driven back in the same hole.

I’d say after a roof deck has had three layers, or three single layers it’s time for a redeck.

Consider this, the nail holes for each layer will be in fairly close proximity to each other becuase you can’t adjust the first course far enough.

If the roof deck has had 3 layers that’s approximately 972 nail holes per square.

Heres the math.
27 shingles per bundle
4 nails per shingle
3 bundles per square

324*3=972 = Redeck! = )

Most older roofs are at a 5" exposure, so when you put new 5 5/8" exposure shingle on, the nails holes won’t line up.

That is a good question Ranch.
it will be interesting to see what the engineers have to say about it.

About pulling vs pounding nails.
I let my men do it either way unless otherwise specified.
Myself, I pull them.
It seems like that is all I do all day during tear off…

Yeah didn’t really give that enough thought. Was trying to make it out of the house this mornig. hehe

But it’s still alot of holes! The reason for my position though it because I get insurance companies to pay for redecks if there’s been 3 or more layers on the roof.

Ridge, Ax… wildcards to consider are the first shingles ever installed were racked & subsequent roofs were NOT.

Also, what about staples for @ least 1 out of 3 full roofing jobs.

That oughta screw up Ridgewalker’s math a bit. How many holes do you have now?


Staples seemed to leave only a pinhole compared to roofing nails that leave larger holes and often split the decking trying to remove them.

Staples are no longer used (that I know of)for nailing shingles.However,mobile homes may still use them.

I still run into a lot of newer roofs that have staples,but only in areas near a moble home manufactuering plant.

[quote]Ridge, Ax… wildcards to consider are the first shingles ever installed were racked & subsequent roofs were NOT.

Also, what about staples for @ least 1 out of 3 full roofing jobs.[/quote]

LOL Ranch!!

Ok maybe I’m stupid but what does racking have to do with how many nails per shingle. Each shingle should still have 4 nails. Yes?

Ok so if you have 2 layers fastened with nails and 1 layer with staples you’d have approx. 1300 holes per square. :stuck_out_tongue:

Racked means the nail holes won’t as readily line up (or be in the same proximity) as the other two out of our supposed 3 roofing jobs.

Also, if you’r of the “remove all nails” theory, staples can sometimes be a more pain in the a$$ prospect to remove, thereby causing greater damage to the deck.

I’ll tell you one thing, I love me some “Cats Paw” type pry bars.

Ok I see what your getting at, I do know what racking is. Just wasn’t sure what your were meaning.

Find a picture of the Estwing flat bar/cats paw, it is the chit.

I’ll go on record as saying I don’t like racking on ANY of my projects & Dougger22 thinks it’s OK for 3T’s but not Dim’s.

The chicken ladder is too close to the stagger, it encourages “skip nailing”…

Not only does it encourage skip nailing, it screws up the color pattern and after the roof has aged you can tell it was racked by the vertical lines that racking creates. It’s not recommended by any manfucaturer.

I don’t think you can encourage a real roofer to do anything he did’t want to do ,them are some hardheaded rascals.I beleive anyone that would skip nails would do so reguardless if the ladder was there or not.That roof being steep ,the shingles would more than likely start sliding after a few years without having 4 nails.

i dont see any difference between a vertical rack or a diagnal rack.
who made up the idea that a diagnal line looks better
than a veritcal line.

dont make no difference to me.

as far as old notty pine deckin getting beat up and
becoming weak, after 3 or 4 reroofs.
yes ive run into it.

plywood hasnt been out long enough yet to see
3 roofs, so cant help ya there.

as far as nails, i like to leave the flat ones
and pull the ones that have debri under them or bent over.


to guys who leave all the nails, what happens to a coil gun after you have hit several of those left over nails? After all your bound to hit them and there gonna be close to the same place as the new nails. also how do you keep those old nails from someday pushing up through the new shingles? Our workers are taught that if it is not holding something it has no purpose so pull the darn things out. I don’t to replace someones roof or worse thier property simply because someone left old nails in their roof. That’s just shotty. If you don’t think so ask the manufacture what they would prefer then tell the customer what the manufacture suggest and what you are actually going to do.

same thing happens to my gun when i hit an old simplex , as does a new simplex.
it shoots it through it.

only seen a previuos roof nail back up through new felt and shingles, maybe once or twice.

as far as askin the manufacture,
think i better not.


[quote]i dont see any difference between a vertical rack or a diagnal rack.
who made up the idea that a diagnal line looks better
than a veritcal line.

dont make no difference to me. [/quote]

Whenever We do 3-tabs we rack them.
That is how 3-tabs are done…
I don’t know any other way to make them come out straight, vertically.

If you know how to do them, they are better from an application standpoint.
You can usually put them on faster and better if you take the time to figure out “The Grid”.
2 roofers of equal skill, knowledge, and speed, one doing laminants and the other doing 3-tabs in the rack.
The man doing the 3-tabs will put on more sq/hr consistently.
Granted, this is after the chalk lines are snapped.
The production advantage of going straight up the roof is undeniable.
You do tend to have a need to clear off more of the roof though.
If you have a crew that knows 3-tabs, they will do a steep roof much faster than laminants.
There is a system and it works great if you set it up right.

But, yeah who cares if it is a diagonal line or a vertical line.
By that time you should be thinking about a new roof in the next 5 yrs or so…