Couple Roofing Questions

My shingles are the Certainteed recall ones and I’m looking at redoing the roof. Having a conversation with the broinlaw who is a carpenter in WI and been swinging a hammer for 35+ years got me thinking. Ventilation and valleys.
In the Rochester area all the valleys I have seen on shingled roofs are a woven type installation. As in two roof lines blended together or one roof up thru the valley and the other over it. In his area of SE WI all the valleys are exposed metal. As in a several inch wide area of no shingles. His claim is the metal is better. So is there an advantage or disadvantage to either? Is the woven just a cosmetic deal? Is it regional by the roofers? Are there labor savings?
And then I have the same question on a full ridge vent vs the standard static vents. I understand a multitude of roof lines and ridges in some of todays houses may not allow enough ridge vent length and thus statics. What are the advantages or not of each. Looking for some insight and discussion.

I believe valley tin was replaced with shingle jobs, because of how it looked… now you can get it any color under the sun, so I would believe it would be a cost savings, going with the tin. Also, in my opinion, an ice dam is less likely to form using the tin. (disclaimer…I am not a roofer) Also, I believe the ridge vent, keeps a nice clean look to the roof, no vents sticking up and I believe they breath a whole lot better being vented almost the entire length This is by no means gospel, but on my last shingle job on my house, I went with the ridge vent and am happy (no valleys on my roof)

Ridge vent is a LOT easier if DYI especially if there is a possibility of you ever having to do it again saves a lot of time not having to go around each and every vent-especially when the vents are all in different shingle layers

Everyone I know puts valley tin on the bottom, then a layer of weatherguard, and then shingle over it, that way you get the cosmetic look of the shingles, but the protection of the valley tin. I am not a roofer, but do run a lumberyard and sell to a lot of roofers.

Tore my certainteed off after they said I had no claim because I did not have enough ventilation-vents. Metal roof was the same cost as shingles. Only thing I do not like is the avalanches as the snow melts. Place the snobar/snoblock in appropriate places.

General contractor in rochester for 9 years. Shingles look much better and in conversations with my shingle reps they say there is no benefit to using valley tin. I think some guys feel the tin allows water/snow to move easier but I thought it was purely personal preference.

I will be redoing my roof shortly and will run ice/water shield up the valley. Tar paper horizonal as usual and then weave shingles through the valley. If you do not nail within 10″ of the valley per recomendation I don’t think there is a problem.

The ridge vents are IMHO a superior product that functions and looks better. A vent is supposed to allow hot air to leave the attic that has entered through the eave vents. A standard vent traps air at the ridge line and holds more heat in the attic. They do cost more but are worth the money to me and I recomend them to my clients.

Good luck.

I spent a few years roofing houses and Farmboy nailed it. Generally speaking, the most important thing to do is follow the shingle mfg’s instructions.

Right Brent, you can put valley tin in the valley if you want but theres no need too. Heres why;;; Like Brent says you can weave the valley with 30 lb. felt, that in itself equals 60 lbs. Then when you shingle you weave the valley with your shingles.

Lets say your useing 120 lb. shingles. When you weave the valley your getting 240 lb. of coverage, 120 lb. more then the regular run of the roof. Even with ice dams, by the time the valley leaks its time for a new roof anyway. One thing you have to do is make sure theres no shingle joint in the valley. My prefered space is atleast 12″ from the valley, even if I have to cut back the previous shingle, so the final shingle spans the valley. A shingled valley is pretty cool and looks really great,,,plus its water proof and no need for valley tin and has better protection then the main run of the roof,,,2 layers of paper and 2 layers of shingles.

Theres no need for ridge vents if the soffits aren’t ventilated soffits, (eaves). If theres no ventilated soffits, then end vents are the best and big enough to draw and let loose of the heat in the attic. Plus roof vents that are spaced accordingly over the run of the roof and high enough twards the ridge to let air flow from the lower vents out the upper vents. Even if you buy the most expensive shingles you can buy, if the roofs not vented the heat will bake the asphault in the shingles and you’ll get half the life from your expensive shingles, the roof has to be vented to draw cooler air in, to keep the shingles as cool as they can be. Good shingles plus good air flow equals a good life span on the roof. On a hot day roofs get to 145 degrees on a thermometer, you can’t take a shower in that heat, thats how hot they get. Do that for 25 years if a roofs not vented and believe me the shingles won’t last what thier guaranteed too.

If I had to choose one, eigther a well vented roof with cheaper shingels or a roof with expensive shingles and no vents, I’d choose the vented roof with the cheaper shingles, heat bakes a shingle and makes them brittle by drying out the asphault. Let them weave the valleys with 30 lb. felt and then make sure they weave the valleys right with the shingles and you’ll be ok.

check with the manufacturer on how they suggest the valleys be run as certainteed will void the warranty of the roof if it is woven that is not their recommended application. Also a thing to remember with vents static vents in your roof create leak points compared to a ridge vent or gable venting. Any hole or obstruction protruding thru your roof is a potential leak. Ridge vent will still work without soffit vents just not as well. Remember hot air rises. there is also the issue of over venting a roof which will cause condensation and rot in your attic. Also causing heat loss due to the stack effect of heat rising to much air moving will draw heat or A/C conditioned air out of your house. good luck

Great discussion. I know without soffit vents whatever you have up top is pointless. Any thoughts on leakage of rain or snow blow in with ridge vs statics?? Seems like I always have snow laying on my insulation with my current vents. And as far as valleys go I understand the cosmetics of the woven and the idea of dual shingle layers. I guess my wonder is why is this area one way and his area in WI is all metal valleys completely the other. Seems like a regional thing and maybe not based on facts or science??

I roof for a few years. Personally go full ridge vent whenever you can. Most building codes require ice/water barrier on eaves and valley. The valley is a personally choice, though I would use the metal valley. Also I would use a synthetic underlayment instead of felt..it’s just better. Permafelt or Summit are really good.

Another thing I would go with a class 4 rated shingle because you save 20% on your home insurance premiums. There hail resistant and the cost difference is so minor you will recoup the money in the long run.

Also always tear the old shingles off.

I’ve been in residential construction for nearly 30 years. Regardless of the product manufacture’s claims, warranties,…I put the most stock into Building Science for true testing of best practices and procedures and simply comparing things to everything I find when doing remodel projects. Amazing what you find wrong with a house long after the original install.

Venting – For obvious reasons, ridge vent will give you a much more superior volume of ventilation. This is only given that you have sufficient amount of soffit vents. In addition to the soffit vents, the baffles leading from your soffits to above the insulation line must be unobstructed. This allows the maximum flow of ambient air to travel on the under neath side of your sheathing material. Having proper flow will greatly reduce ice dams, cool the roof in winter and heat in in summer. Also, make dang sure your using a ridge vent that has external type baffles I’ve been to a number of test houses and was shocked at the performance difference during the attic smoke test. Here’s a link to what I am talking about Youtube smoke test
Valleys – Both perform well when installed correctly. The key there is that the installation must be done the right way. IMHO the woven method is the easiest to have guys screw up. You could weave 600 lbs of felt and it won’t work as a moisture barrier if they didn’t form it to the valley and punctured it while installing shingles. Tin is probably the quickest method and used by roofers that are “in and out”. There are a few things that I like with the tin over the woven method. 1. I only spec the “W” valley tin. Having the raised center will allow for some air flow to travel and cool the middle of the tin in winter. 2. nail holes are further out from the center of the valley. If you ever get up in an attic and look at ice dam failures, you will realize how important this is. 3. less opportunity for catastrophic failure. 4. covers any irregularities in the valley.

Ice & water shield – Regardless of which method you use, make sure you spec Ice & Water Shield at all valleys and saddles. I over build and very seldom do anything that is minimal code compliant. My standard on new home construction is 6 feet at all valleys. That is one layer down the center of the valley and a layer to each side for a 6 foot coverage.

Thanks for the input guys. Randy I’m kinda like you in regards to going a bit extra. It only costs a few bucks more. Is there a brand of ridge vent you think is best? I have full soffitt vents and the baffle chutes are in place because I redid the insulation about 10 yrs ago. I’ll have to check on any insurance discounts for shingle type. When using the “W” type valley how far back do you cut the shingles? Again great discussion. Thanks

When using the “W” type valley how far back do you cut the shingles? 1-1/2 to 2″

I spec the 12″ ShingleVent II. Though, there are a couple of other equivalents. Stay away from the “rolled roof vents!”