New Roof Advice

I’ve gotten 3 estimates on getting a new roof and need some advice. First a little background on home. It is 20 years old and is located in central NJ. From the inside crawlspace, the decking looks relatively intact The roof has standard 3 tab shingles. A few have fallen off and some wear is apparent when viewing the roofline from ground. Shingles are flat for the most part but have some rotting on one fascia. I have some algae/mildew growth along the north siding with some staining on the roof as well. I have continuous soffit vents all along home but no ridge vents. The garage employs a gable vent (south side of home). The main roof is approximately 40 linear feet but the peak only runs 25 linear feet and has 3 mushroom vents and a small power vent. There is one skylight. The only problem area I know of is along the vertical climb between the main roof and the adjoining roof. A small leak has occurred at least twice there (evidenced by some water stains on drywall inside house) and I suspect some problem with the flashing possibly. This only occurred during a continuous rainstorm of 72+ hours.

My first estimate was from HD and it came in about 50% higher than the others. For other reasons, not even considering them at this point but they serve as my benchmark for materials.

Second contractor came when I wasn’t home and came back with a proposal to perform roof overlay using Gaf TL 30. Since I was not home, I do not know if he physically went up on the roof to do his assessment. His price included ridge vents, reflashing chimney and pipe flanges. Upon request, I also received quotes for tear-off and changing to GAF TL Ultra.

Third contractor recommended using OC OakRidge Pro 30. He felt the roof decking was structurally sound but recommended tearoff. He was against using GAF (said he did not like cobra ridge vents and OC was a better product in his opinion) but he was certified for both.

The pricing for the two contractors are about the same when comparing tearoff quotes. However, they employ two different shingles. One is Gaf TL 30 (70 mph rating) vs OC Oakridge Pro 30 (110 mph rating). Most places I have read prefer Gaf over OC but these are two different products so not easy for me to compare. Also, the contractor who recommended OC also recommended not to upgrade to OakRidge 50 unless I really wanted to burn the money.

The questions I have are:

How can I get a better comnparison of products? If I compare the OC OR 30 to the Gaf TL 30, it seems the OC is the much better product, yet their quotes are so similar. What product would I compare the Gaf Ultra to if I use OC? What is the general opinion of this OC product?

I’ve read that when employing ridge vents, all other types of venting should be removed (except soffits obviously). The third contractor said I should leave the vents I have existing as my peak does not run the entire length of roof. Second contractor was indifferent. HD said they must be removed. What’s the correct answer? All vents are on one side of the slope.

After looking over all the materials, I seem to prefer the Gaf Camelot/GrandSlate/Slateline look but not sure if they are worth the cost.


If you have alge growth [staining on your roof is algea growth] you cannot overlay.


How do you know that you have soffit vents?

How is a Home Depot estimate a benchmark for materials?

Your leak problem has nothing to do with the flashing. Your roof is shot. A problem with the flashing would not take 20 years and 72 hours of rain to show up.

I know of no problem with Owens Corning shingles. Owens Corning ridge vent has got to be the worst I have ever seen. Tell him to show you the Cobra vent and the Owens Corning vent. You will see the difference.

in my opinion, GAF is by far a superior shingle to anything that OC can produce. and ask to see GAF snow country vent instead of cobra. it is a very nice sturdy vent and a bout the same price. i dont like any roll vents. they dont look as smooth on the roof usually.

I figured that the algae growth would prevent me from being a candidate for overlay but I guess the contractor either missed seeing it or doesn’t believe it to be algae. The area that is affected is maybe 6-8 sq. ft.

I’m pretty sure I have soffit vents as that’s what they look like to me and each of the contractors seem to agree. There is vinyl molding running along the entire perimeter of house including garage with thousands of holes. (Couldn’t link picture because of spamguard)

The HD comment came out wrong. I meant to say, I was using their recommended products as my benchmark (They recommended Gaf TL30 or TL40 or Ultra with cobra ridge vent).

Let me elaborate a little about the leak. When I bought the home, home inspector saw no problems with roof. It was in good condition for age. However, he did point out some water stains that seemed odd. Recently, there was a long rainstorm and it leaked right where those stains were after the third day. It has not leaked since. I’m not an expert in these things but it seems to correspond to the head wall flashing (or is this called step flashing?). It’s where the small roof meets the main portion of house against the siding. The shingles actually are good in this area as I went up there to check and there are none missing and granules look better than most. The inside of the house has drywall where this slope is and that’s where the stains are.

I did not compare the OC vent to the Gaf vent side by side and I probably couldn’t honestly tell the difference. The contractor that recommended OC said that Gaf does not use baffles and OC does.




You have a vented soffit material that may have been put over a solid soffit. That is why I brought that up. People assume that they are vented.

Reread my comments on your evaluation of the flashing.

I knew you did not see the ridge vents. I told you to ask the contractor to show you the products.

my only problem with o/c is that i did a few o/c roofs a few years ago and they all streaked REALLY BAD . Never had the problem with GAF.

oc 110 mph wind means “tested” not warranted. gaf 70 mph is the warranted speed. oc only warrants theirs for 70 mph. GAF is the largest roofing manufacturer in the country. but they both make you jump through hoops if there is a problem.

IMO most comparable materials are good quality and are not a cause for stress.

Concentrate on finding a good roofer.

And tear off the old roofing.

Is there an issue with ventilation now? If you don’t have any ventilation problems with the current vents, why change the venting.