General Questions / Need Advice

** I don’t know which Manufacturer to choose. I don’t want the cheapest nor do I want the most expensive; just a good quality shingle. I currently have two roofs on the house and it will require a tear off. It is visibly obvious that there are a number of pieces of plywood that need replaced … lots of dips in the roof. I received a quote of $7,650 (worst case scenario) with replacement 1/2" plywood and GAF Timberline 30 shingle; 4/12 Pitch. I don’t know if I should go with GAF or Certainteed (I thought the Certainteed felt rather thin…maybe an incorrect perception). I am also getting the Ridge Vent, which leads. I currently have vented soffits (perforated aluminum); however, this was installed over original soffit (which looked like heavy cardbaord to me) that had cut-outs and wire mesh over the cuts-outs). Some of the original pices fell out during installation; some pieces didn’t fall out and were just covered over. Will this soffit still allow proper ventilation of the attic in conjunction with the Ridge Vent? As I am getting “up there” in age, I am certainly not looking for a Lifetime Warranty nor a 40-50 year shingle (whose Lifetime-HA, HA!) HELP! Is Timberline Prestique 30 a Good Shingle? I live in Maryland and the summers are quite hot/humid.**

hold on megan ill let
some of the snowbirds here help.
im more a sunbird.

one thing that is universal though.
try to do what is woking for your neighboors.
stick to what is commonly sold.


Thanks for responding. Well, the majority are putting on the 3 Tab, which I definitely don’t want again. I like the look of the architectural shingles. We do have a HUGE problem here with algae on the roofs … every house in the neighborhood has been affected by it. Does the situation with “covered over soffits” provide enough ventilation along with a Ridge Vent? I also have two vents at the end of each side of the roof … it is just a straight rambler 60’ x 32’ (which includes the soffit overhang).

Certainteed LandMarks and Tamko Heritage and GAF/Elk Timberlines, all have good value in both the 30 year through 50 years varieties of shingles.

When people are hitting their prime, I like to know if they intend on staying in that home for the next 15-20 years. If that is the case, then a bump up to the 40-50 year might be in order, because if you want to sell in 20-25 years, you could stil have a roof that looks like new.

But, that totaly depends on the proper balanced ventilation.

It sounds like your vented soffit panels were installed over most of the old wood, so, ion effect, they are not functional at all, or at least very minimally.

You could have the Smart Vent from DCI Products installed, which is a shingle over style intake ventilation system and also use an Externally Baffled Ridge Vent, like Shingle Vent II or Cobra Snow Country.

This is so very key to the longevity of the roof, yet done incorrectly nearly 90 % to 95 % of the time, either through Contractor ignorance or home ownber initial budget looking for the cheapest way to do the current roof.

It pays wel off down the road, when you do not have to re-do the roof 12-15 years later, due to neglecting the Balanced Fresh Air Intake Ventilation and the Attic Exhaust Systems.


Thanks, Ed…I don’t know about “people hitting their prime” … it is more like “just OLD.” This will be the LAST roof that I put on this house, that’s for sure. Anyway, I went to a Roofing Center this afternoon and brought back some samples. As luck would have it, I prefer the GAF Timberline 30 Shingle, but found the color that I like in the Certainteed Landmark. I know this is going to sound really dumb, BUT why does the Timberline shingle have Sticky (Tar?) on the “good/top side” of the shingle (also on the back, of course) and the Certainteed does not have any sticky on the good side, but two strips of it on the underneath side? Additionally, the one quote that I got stated 1/2" plywood and 15 lb felt. I noticed on one of the discussions, the preference seems to be 5/8" plywood. What about the felt? I’m sorry to be soooo uninformed, but I really need all the advice that I can get. I’m not looking for a “cheap job” but I also don’t want to be taken to the “cleaners.” :?

Code requirements and rafter span dictate the minimum thickness of plywood to be used.

If you use 1/2" plywood, use the 4-ply version instead of the 3-ply. It is significantly more structurally sound.

Thicker is better, but what is your budget? 5/8" costs considerably more than 1/2" 4-ply.

The location of the tar strips does not matter, it is just one manufacturer versus another on how they do things, They both stick to seal the shingles down.

Did you look at the color options from the Tamko Heritage line of Architectural shingles?

Which color did you like best?


I liked the Burnt Sienna in Certainteed. Something that is really bothering me about the Certainteed is “the flimsy feel” of it. I was just moving it around outside in the shade and in the sunlight to see how it looked and leaned it up against the house siding for color coordination, and the sample has started ripping in a couple of places just from being handled!! Maybe I’m just getting freaked out over this because it is a big job, and I want to select the appropriate shingle … just have that “nagging uncertainty” about Certainteed Landmark versus Timberline Prestique 30. But, I have noticed on the forum that both are always mentioned as a quality product. If I recall correctly, the Contractor I spoke with didn’t think much of Tamko … Is a 40 SIGNIFICANTLY thicker than a 30?

Everyone has there own preference.

It is best to allow your contractor of choice advise which product has served him well over the years in your region.

With Tamko, the Rustic Slate seems to be a good match, or if you wanted a little more deeper red, then the Rustic Redwood.

Their shingles have always been very good for my company to install with no post job problems.

GAF/Elk is a recent merger with a new formulation, so some guys are hesitant to jump on the new bandwagon right away and will see how they hold up, before being disciples of those merged brands again.


dont be alarmed by how the shingle gets flimsy in the sun they all do it.
and the fact that you say your neighboors have 3tabs concerns me.
do they have the 3 tabs because the they cant afford demensionals or are the 3 tabs on there because there is not enough slope for demensionals.

you must have a good slope for demensionals.
3 tabs work better on low slopes.
very important.

3tabs are not just cheaper shingles, they also
and more importantly shedd water better due to the water keyways.

dont get me started on 3tabs.


Well, it is a hard to say; but, my guess is that the other homeowners don’t want to spend any more than they have to … just a roof that looks OK and is “new” for a possible re-sale (as I said earlier, that algae has affected the whole neighborhood and the roofs look terrible). I saw another Rambler on the street behind my house that has the Dimensional Shingles and it looks great. I don’t know the people, but I guess I could go knocking on the door and ask them what Brand they bought, etc. I don’t PLAN on moving anytime soon, but who knows how long I will be in this house, as circumstances do change unexpectedly. However, I do look at any major improvement as an investment; of course, my children will inherit the house after I “croak” and will, of course, put it up for sale. If I don’t make repairs/improvements, these are issues that they would have to deal with for re-sale … plus while I am living here, I want my house to look nice and well maintained. This is what I “perceive” from reading this forum –

  1. Either Timberline 30 and Certainteed Landmark are quality shingles.
  2. For replacement plywood use 5/8" if budget allows. If not, 1/2" 4-ply.
  3. Felt – didn’t get a definitive answer ???
  4. MAKE SURE intake ventilation is sufficient. Check soffits (because of coverage of SOME of the original soffits being covered over with perforated aluminum).
  5. Have Contractor cover over Gable Vents from the inside (because they will act as an “intake” with a Ridge Vent.)
  6. Ask how many Nails they use per shingle. (Minimum of 10 for Laminates/Dimensional shingles)

Another question – will this work cause damage to my gutters? Should a statement be added to the contract about any collateral damage by workers?

Are there other issues that I should address?

Thanks for your help

Felt is most important when the old decking is getting covered prior to the shingles being installed.

For the few dollars more, I always use 30 # but that is me just stepping it up a notch from 15 #. Others may say that 30 # wrinkles more, but if covered up with tarps each night before shingled, that is not true. It is also safet to walk on without tearing.
For an even better upgrade, some of the sythetic felts are recommended. I offer that as an option.

It is not critical, as long as it is not left exposed for long durations before getting shingled.

Not 10 nails per shingle with architecturals. Where did you read that? 4 is standard with proper placement and 6 per shingle if very steep or in a high wind zone.

Put it in writing to protect the gutters. I use a bracket inside of the gutter that does not allow the ladder to come in contact with the gutter so it does not get bent. Ask for additional gutter brackets to be installed if yours are currently 24" or farther apart. No big expense in doing that and it should only cost about $ 1.00 per each extra bracket installed.


Another Contractor was out this morning; he will work up a quote and call me back. However, I did get a RED Flag … I was explaining to him about my Soffits and I want to be SURE that I have proper ventilation. Then I said that I wanted the Gable Vents covered up, since I am getting a Ridge Vent. He said “Why, the more the better” I told him that I was on a Roofing Forum and that all the Roofers said that the Gable Vents would then become like “intake” vents in conjunction with a Ridge Vent. He said that he had never heard of such a thing… so…I’m glad I found this Forum.

The, “I Never Heard Such A Thing” is a major Red Flag of a lack of knowledge. That is one of the most basic things discussed in any ventilation manufacturers studies. It shows that he has not studied his industry and is not dedicated to providing premium performance of the products installed.

At least when Dennis of Roofers Review on this Forum disagrees with that principle, he has his own reasonings and backs them up, which I disagree with, but respect just the same.


HI, seems Ed has answered all your questions. Just wanted to say that the closest GAF/ELK equivilent of Burnt Sienna is now called Hickory, if that’s the color you like.

Well, I do have another couple of questions. The second Contractor also mentioned using OSB instead of Plywood (first Contractor said he uses 1/2" Plywood). Anyway, I don’t know if there is a consensus amongst the Roofers/Contractors regarding OSB vs. Plywood. I told him that I would let him know for sure which one I wanted to use. He said the OSB is more structurally sound and bends/dips less than Plywood.

Secondly, if there is A LOT of the “original Wood/Cardboard Soffit” on the house, can it be CUT OUT from above if the Plywood that covers the soffit is removed around the overhang of the house?

Tar Man you have quite the “sense of humor” … I was reading another thread and was actually laughing out loud at your posts. :stuck_out_tongue:

Hello Megan…I did one job exactly like what you described. I romoved the sheething and cut the cardboard soffit out from above. I also ripped of 1 roof theat had no paper at all, and was osb. not one bad sheet. that was 20 years old. Hickory is a nice choice, by the way, I sell only the Gaf/Elk 30 yr they are elk shinlges with the timberline color pics. They also have a 10 yr stain guard warrentee for blue green algea.

Thanks, JWoofs…I thought of that “myself” about the removal of the old “cardboard soffit” from above (thought you guys might think it was a crazy idea). Well, my son-in-law also told me I should use OSB; however, I noticed that several posters prefer the Plywood – but they didn’t say WHY they preferred it over the OSB ?? In one of my posts I stated that 10 Nails should be used (I don’t know where I got that); so what is the number – 4 or 6? I was reading a thread (maybe on a different Website) about some guy’s new roof shingles starting to fall off !!

I haven’t heard back from the 2nd Contractor yet … he probably got tired of hearing me say “Well, on the Roofing Forum the Roofing Experts said…” HA!

lol, you are just trying to get educated on products so you can make an intelligent decision on your project so you can go forward w/no regrets. The job I spoke of alse had plywood and was dryrotted from lack of ventillation. I used osb. I sold 320 sheets last year on about 10 jobs. osb stands for oriented strand board it is an engineered wood. Original strand board did not stand up to moisture and condensation and that is why OSB gets a bad rap. Plywood is wood, it dries up, and as it drys, warps and buckles and actually will pull nails out of rafters over time. Also, have your contractor specify that he will renail the plywood after he removes the shingles because removing the shingles will loosen the plywood nails and this will cause damage to your new roof in the hear future.

A while back I read a technical article by an engineered wood product manufacturer who made both products. The article was on plywood versus OSB Versatility, Stiffness, Creep - edge swell.

Here are the highlights to support my utilization of CDX instead of OSB.

OSB swell is generally greater than in plywood due to the release of compaction stress in OSB created during the pressing of wood chips into an OSB panel. Plywood that has swollen will return to its nominal thickness as the wood dries. OSB will remain swollen to some degree after it dries because the panel will still have the higher “compaction ratio” that was present as of the date of manufacture.

The comparison below, undertook by the APA, lists the thickness swell (in percent) using a water soak test.
Plywood Average swell= 6% to 8% depending on thickness
OSB Average swell= 10% to 15% depending on thickness

Over a period of time, when subjected to high humidity or a series of dramatic wetting events, OSB is more prone to panel swell than plywood especially at the edges. Panel swell is most noticeable along the edges where it is critical for flooring and roof sheathing to match-up as not to show through the flooring or roofing materials.

Research done by the USDA Forest Products Laboratory (Research Paper FLP-RP-574) shows that over an extended period of time, under low constant loads and temperature, and in high-humid conditions, OSB will sag or “creep” more than plywood.

50% RH Fractional creep values
1.4mm Plywood
1.7mm OSB

85% RH Fractional creep values
1.9mm Plywood
5.2mm OSB

Cyclic RH 50%-85% creep values
2.0mm Plywood
4.6mm OSB

Long-term, plywood sags less than OSB in humid conditions. In humid areas with vented attics and crawl spaces, using plywood for roof and floor sheathing can reduce risk of sagging roofs and floors.

APA Technical Note N375B states that plywood panel bending stiffness is 10% greater than OSB at equal joist spacing. Panel bending stiffness is the capacity to resist deflection.

Density of plywood is 34-36 pounds per cubic foot compared to OSB at 38-42 pounds per cubic foot.
One 23/32" 4’x 8’ plywood piece would weigh approximately 67 lbs.
One 23/32" 4’x 8’ OSB piece would weigh approximately 78 lbs.

Plywood is approximately 15% to 19% lighter than OSB. While the additional weight of OSB does not mean increased strength, it just means that it is heavier to handle on the job. In addition, OSB’s higher weight means higher thermal conductivity (thus slightly less R value) than plywood.

Plywood and OSB: Screw withdrawal or holding ability.

Group 1 plywood, made from the strongest species of wood such as Southern Yellow Pine, holds screws better than OSB.

Plywood and OSB: Nail withdrawal or holding ability.

As shown in APA report T2001-3A, plywood generally has higher nail withdrawal values using plain-shank, ring-shank, and screw-shank nails, even though OSB has a higher density than plywood. The numbers below reflect dry test conditions. The numbers vary some when tested under dry to wet-redry conditions.
Withdrawal strength (lbs/in. penetration)

Plain Ring Screw

5/8" Plywood
Mean: 79.7 316.3 83.7

23/32" OSB
Mean: 67.6 281.5 63.9

Nail withdrawal strength measures the force to pull the embedded nail from the nailed parts.

After roof sheathing or sub floor panels are nailed to the framing, nails will remain in place better in plywood than OSB.

Under severe weather testing, plywood is shown to be more impact resistant than OSB. Plywood outperforms OSB in the South Florida Building Code (Dade and Broward Counties) mandated use of the “large missile” impact test for materials used in walls and roofs.

Plywood is more impact resistant than OSB. This provides resistance to flying objects in high wind situations. More impact resistance provides added durability against accidents caused by impact on floors, roofs, and walls on the inside and outside of the home.

Check out this link for more information.

The previous link include links to 6 very comprehensive articles relating to the comparisons of plywood versus osb, both pro and con for either side of the fence. Use which ever endorsing information suits your purpose.


Another factor to consider, depending on the interior attic and home Relative Humidity factor and the proper balance ventilation to expell this moisture, the product quite possibly could be affected resulting in negative consequences.

Secondly, according to the APA, (Aperican Plywwood Association , now called Engineered Wood Products Association), per a document supplied to me via Certainteed, when OSB is delivered to the job site, it is in its driest state. Each and every sheet in the stack of OSB MUST be seperated by a minimum of 1/2" air gap to absorb the external ambient humidity for either 24 -48 hours. I forget the phraseology exactly, but that was the ludicrousness of the specifications prior to being capable of being installed properly to minimize the negative affects of the swelling that will invariably occur.

That would never happen in the real world!