No Plywood?

phinsher

Howdy roofing guys. I'm a painter with a roofing question. My home was built in 1935. It's been added onto and repaired in sections before I owned it. It is now time for a new roof. The current roof looks to have three layers of shingles so a tear of is necessary. I've contacted a local roofer who has been great to deal with. Returned phone call promptly etc. He's provided me with a proposal which seems to address all the important issues. Here's my question. On several sections of the house there is no plywood. There is a layer of cedar shingles that are on top of rows of 1x3's. The 1x3's are spaced about 3 inches apart. Does this need plywood or can the felt paper and shingle be installed over this.

The guy I'm dealing with said everything would be fine, I'm just not sure that he's aware that part of the roof has no plywood. I don't want to pi$$ him off or insult him so I thought I'd ask you guys before addressing it with him.

N.E.Bldg&Rest.LLC

I would tear off those sections down to the framing and start fresh, And you might have to replace more than those sections, but you won't know until all the old roofing is off.

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Teetorbilt

The roofing system to which you refer was quite common, I did a few in my younger days and a town center that we had here lasted for nearly 100 yrs, albeit with a few leaks during some storms.

I'd really consider a new roofing system in your case. I'll let the real roofers chime in now.

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jmic

Phin,
I deffinatly wouldn't shingle over the roof boards spaced as you describe, you could plywood over those boards or like mentioned above strip down to rafters and plywood over rafters. What spacing do you have on rafters?

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reveivl

I renail the strapping and ply over. Definitely wouldn't paper over 3" spaces Rich.

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Grumpy

You have to sheet over the spaced decking to create a proper nail base for the new shingles. We do this all the time, and do a few roof just like this every year. Some guys will fill in those spaces with 1x3 but that's crapola IMO. One more thing, when sheathing over the spaced decking youa re going to want a metal flashing at all roof edges to protect and hide the plywood. Also when nailing the new plywood, sinkers should be used and penetrate through the decking and into the rafters.

Did he know it had cedar or did he say roofing over spaced sheating is no problem? Either way it doesn't build confidence. Almost all guys in my area have a line saying carpentry will cost additiona, some like me even give a per sheet price. A few companies don;t add the cost of the wood to the estimate ammount, start the job resheat the entire roof and submit the invoice with all the wood. Legally they can do this, though I find it unethical.

River Rat Dad

To add to the fine advice above, It would be a code violation NOT to install the plywood/OSB over the "spaced boards" as we call them. Filling in the spaces would not fly in MI. and is a bad idea regardless.
Its possible with a 71 year old house the rafters are not as uniform as you would like to end on rafters. This is where I differ from some guys here. I would contend that it would'nt be necessary to end on rafters if: 1) it means cutting a bunch of sheets back 2 feet because the some rafters are on 26" AND 2) the existing "spaced boards are in GOOD condition and will hold nails.
In that case, hit the rafters where they are and pepper the crap out of edges that don't end on rafters. When you go to shingle use 1 1/4" nails and they too will go through the plywood and in to the spaced boards to add additional holding . Remember don't and at the same time....

copusbuilder

I think he is talking about shingeling over the cedar shakes. Used to be common here. They would lay #30 pound felt and install dimensional shingles over that.
As the shorter shingle life became more apparent we saw this become a less and less used system. I still see it being done in the county areas where the codes aren't enforced.
If you are going to live there a while I would strip and deck. I agree that decking over "sound" 1x3" can be quite acceptable unless tie ins 3won't allow it.

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phinsher

Thanks for the input guys. Seems the guy checked on 3 areas that did have plywood and assumed the entire roof was sheathed in plywood. I had him back out and he worked up another price based on sheathing the entire roof before installing shingles. Luckily for me I was able to prevent a $3000 surprise at the end of the job.

Is there anything else that sometimes is overlooked on roofing estimates?

Just to let you know he has included all labor and materials to:
remove all shingles from house
15lb felt paper
aluminium drip edge
30 year dimensional shingles
reset and flash base of chimney
install all necessary wall flashings
install ridgevent on peak
Magnet sweeper to remove loose nails
clean and remove debris
1 year gaurantee
and now install 1/2" plywood

What do you guys think?

N.E.Bldg&Rest.LLC

How about a cricket where the roof meets the chimney?

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River Rat Dad

In my state a cricket would be required by code if the chiminy is over 30" wide.
Also if the plywood is going over the top of the existing roof boards then 1/2" is overkill, 3/8" is plenty. If he is removing the existingdecking down to rafters, then 1/2" at least. Maybe 5/8"
Is a one year guarantee common where you are? In my area 10 years is the norm.

Slemons

I am a new poster here on this site, so I will chime in if you don'y mind.

If I were replacing the roof on my has as you have descibed here I would change some of the basic specification to include an ice and water shield on all eaves, sidewalls, valleys and penetrations.

Then I would also ask to up grade to a minimum 50 year shingle, the real cost to this job is in the labor, it cost the same labor to install a 50 year shingle as it does a 30 year. The cost difference in the material is minimal.

There areas that have the cedar shingles will require re-decking with plywood or osb as Grumpy has described, it has been my experience that when you deal withis type of roof that they usally have a crown moulding around the perimeter edge as well so. Generally the existing fascia and rake boards do not come up high enough to meet the new decking and may need to be replaced as well.

I would also make sure that the new ventialltion system includes some provisions for intake ventalltion. Either some sort of soffit vents or a continious drip edge vent system.

Just my 2 cents...Scott

AaronB.

Dont you pay extra for installing the heavies?

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Grumpy

To reply to Slemons above. I agree with the ice shield being necessary, regardless if youa re in a snow climate. Ice shield is a secondary flashing at the penetrations and side walls, for purposes of not only ice but also water infiltration. This is a good idea and standard on all of our roofs.

A 50 year shingle? Pretty much a waste of money IMO. Yeah the shingle is slightly heavier and yeah it probably has a better wind uplift resistance and maybe (just maybe) it will have a nicer look, but it damned sure isn't going to be up there in 50 years, and the 30 year damned sure won't be up there in 30 years.

Like Aaron said, don't you charge more for the heavies? I do. It is more labor, and hook blades, to install the heavies (50 year) than 30 year.

Everyone does things differently, but that's just my take.

In reply to phinsher's question about "any more suprises?" I would like to add that in the areas where that cedar roof meets a wall, the roof is now likley 3" thick. When installing the new roof, it probably won't be more than 1" thick with the new plywood. That means you will have a 2" gap to hide. This is by far our #1 complaint about tearing off cedar and installing asphalt shingles... which is why I tell every customer to expect it no matter who does their roof. Usually in these areas we will install a cosmetic flashing over our baby tins, or use colored baby tins, but other than replacing the siding, it's going to look off.

River Rat Dad

I agree with ice shield at eves and in valleys where I am.But its pointless at sidewalls unless it rolls up behind the siding. Do you guys actually remove all the siding at sidwalls to install ice shield? Also theres no point to ice shield around penetrations unless the ice sheild goes all the way to the eve. Otherwise if moisture ever hits thay ice shield its rolling downhill to felt.

AaronB.

This is why we wrap chimneys/skylights, etc. after we shingle up to the bottom of them. Good point RRD.

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Grumpy

When ever possible, yes... but always on new construction.

Teetorbilt

I'm really glad that I don't have freeze, ice dam, frost heave and other problems. That crap is every year.

We did go on a hurricane craze for the last few years, the first ones since 1947. They only last a few hours.

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River Rat Dad

Grumpy, on new construction rolling the ice up the sidewalls. I hardly ever do new construction so my default mind set is the siding is already in place.

Grumpy

Me too, but I do some. After I bid a job, I usually can;t even get a gc to answer my call sticker shock I suppose.

Existing vinyl siding is very forgiving. Aluminum is my bane. However sometimes you can wrpa the ice shield up and inch or two, and though 4" is preferred, I feel that 1-2" is better than nothing. At least I get an A for effort. An A+ would be actually removing the siding and installing the ice shield, metal flashing then re-installing the siding. I've actually done this in extreme cases.