Do we need to have these ridge vents installed? – CapitalGazette.com

We have been told that we need a new roof and I agree with those who have told us. Not all were in the business of selling us a new roof but friends and neighbors who have gone through similar experiences as us. Most of the estimators mention the option of a ridge vent installed at the top of the roof, some mention it in passing and don't really push it too hard one way or the other, and others, while not exactly insisting it be installed, say that without the installation of a ridge vent, the attic would receive inadequate ventilation, which, in the event of shingle failure, would invalidate the warranty on the shingles.

Some companies also offered to install another vent type about a foot from the edge of the roof for houses which don't have vents or proper ventilation under the eaves. My concern is that our house is old, built in 1967. From what the home inspector told us when we bought it and what the roofing companies have told us when they've done their estimates - some inspected the attic area as part of their estimate - say it is a solid, well-built house and there appears to be no indications of leaking, water damage etc.

This will be the third roof to be put on this house and the attic has gable vents at each end of the house up near the roof peak. Do we need and/or how necessary is it to have these ridge vents installed? I know almost all new houses have ridge vents but my thought is, if it ain't broke, don't fix it! Something goes against my thinking to intentionally cut holes in any roof when there doesn't appear to have been any problems regarding leakage in the past - why risk the trouble, right? On the other hand, I want this next roof to last as long as possible and if these vents are better for the roof and the shingles then I would want them installed.

Ill bet you think you asked a simple question but you didnt. You didnt mention anything about stripping off the old roofing material. If this is going to be roof number three you cant put it over two layers of old roofing. Beside being against the building codes its is a very poor practice. Not because of weight as many think but because the length of the fastener. The nails youd need to attach the shingles would be so long as to not be a good attachment and be susceptible to blowoffs in high winds.

Start at the top.

Ridge venting is a continuous vent strip that is installed at the very peak of the roof. It requires an opening to be cut between two to three inches across the very peak of the roof to expose the attic below over which the ridge vent will straddle. The ridge vent is only half of the venting if thats the vent system youre going to use. A ridge vent needs a continuous air supply from the bottom of the roof edge on both sides of the roof to work - called soffit vents.

The way this works is very simple, yet its the state of the art system. Cool air enters the attic at the lower soffit vent and using the heat of the sun as an accelerator, convects air up under the roof deck, washing the underside of the roof with fresh air, somewhat continuously. Its called a cold roof because the intent is for the temperature of the roof to be close or equal to the temperature of the outside air. It works. I first saw them as a manufactured item routinely installed on roofs starting in the mid-1970s. Gable vents need to be blocked off after the installation of ridge and soffit venting as they will work against each other creating dead air zones in the attic that you dont want.

Roofers like them because they dont have to take the time to individually cut cap shingles as they would if the roof were installed traditionally without ridge venting. The roofers who casually mentioned them were planning to install them. The roofers who told you not having them was going to void the shingle warranty really wanted to use them and employed some sales hyperbole to boost the argument.

Almost any ventilation would suffice for the shingle warranty and shingle warranty is a whole other subject and varies from manufacturer to manufacturer. There are roofs out there whose designs include no venting yet shingle warranty holds. Remember a warranty is a wager between you and the manufacturer that the manufacturers product will last at least as long as the warranty. They usually last longer as the manufacturer is not in the business of handing out new product for free.

Certain ridge vent configurations can leak under extreme conditions. I have seen little snow drifts up in attics under ridge vents after a period of high winds coupled with fine, blowing snow but that was rare. A melting tiny snow pile on top of attic insulation is unlikely to be detected as wet ceiling drywall.

You need to be sure you have adequate soffit venting to supply the air for ridge vents before you rely on them. Thats what the roofers who offered the lower roof vents were trying to do by suggesting them. There is a continuous roof edge venting now marketed to use in conjunction with ridge vents on roofs with insufficient eaves or overhangs but I worry about leakage during ice damming. Luckily we havent had any protracted periods of icing since the winter of 87/88 when the bay froze over at the bridge and they drove cars on the ice at City Dock.

Your house was built with gable vents - those square or triangular openings at each end of the attic. They work fine by themselves but what we have learned through research is that if you have a proper ridge venting system then you should block off the old gable vents. It turns out they work against one another and pockets of dead air begin to form in areas in the attic and thats not what you want.

Keep in mind the function of ventilation over the course of the entire year is more to exhaust moisture that migrates up from the house than to just dissipate summer heat. Make sure your attic insulation is up to snuff. It should be rated at R-38 of fiberglass or its equivalent. When your house was built you were lucky to have had R-19 and even if you did the R-value has drifted lower over the years due to gravitational compaction of the material.

Ensuring a long shingle life has more to do with selecting the best shingle for the job and having it applied by a crew who is careful and does it to manufacturers specifications and local code requirements. Speak to the roofers about drip edge, ice-damming protection and the type of felt underlayment paper theyll use.

If they want to install ridge vent be sure you like the way it looks and preview a sample before it goes up - they are not all created equal. And make sure your prospective roofer is licensed and insured. A quick trip to the Maryland Department of Labor Licensing and Regulation (DLLR) can verify that. About a third of the folks they say have this or that official qualification dont. To quote a past president: Trust but verify.

Keep the mail coming. If you've got a question, tip or comment, let me know. Write "On The Level," c/o The Capital, P.O. Box 3407, Annapolis, MD 21403 or email me at inspektor@aol.com.

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Do we need to have these ridge vents installed? - CapitalGazette.com