Replies

1. 
   John_De_Hut | May 31, 1999 09:39am | #1

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   The one thing I know is to use the right size nails or staples for the install. I've seen them spread all over a jobsite years ago when they first came on the market. The roofers used there standard 1", or 1 and a quarter roofing nails. Use the correct size nails and you won't have a problem.

2. 
   Guest_ | May 31, 1999 07:25pm | #2

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   Kristin. If the house has survived 100 years of no ventilation hwy is it now necessary? You say nothing asbout soffit vents. Not all combinations of ridge and soffit vents work.

   The most recent testing of ridge vents at the University of Illinois shows that ridge vents wihotu external baffles, or those with internal baffles do not worl: They take air in rather than exhausting it.See chapter 23, Attic Ventilation, in my book,_Complete_Building_Construction_ 4th Edition published by Macmillan.

   The correct ridge vent: Air Vent's Shingle Vent II ridge vent will not work with the wrong soffit vents, or with too little soffit net free venting area.

   Use only a double louvered continuous soffit vent and locate it next to the fascia board.GeneL.

1. 
   Guest_ | Jun 02, 1999 07:35am | #3

   *Kristin:They look better if installed all the way to the end of the ridge rather than being held in a foot like folks some do. Here's a link for you:http://www.certainteed.com/pro/proframe/index.html?url=http://www.certainteed.com/pro/ventilation/overview.html

1. 
   Guest_ | Jun 03, 1999 02:13am | #4

   *My folks' Victorian farm house dates to 1898 -- says so on the front porch gable. When the house was re-roofed about fifteen years ago, they listened to Ned Lempke, whose father sold aluminum siding and whose grandfather sold lightning rods, and he talked them into a ridge vent. Afterward, they got as much snow in the attic as falls outside (didn't have to go outside to measure it, anyway), so they removed it a couple years ago. Never before, during, or after the ridge vent was there was there ever any evidence of moisture damage in the attic. So, I agree with Gene and Fred -- the best place for a ridge vent is in the dumpster.

1. 
   Guest_ | Jun 03, 1999 11:15pm | #5

   *Kristin, I have installed quite a few of the capover ridge vents.I have found them to do a pretty good job of venting the attic IF adequate air intake is provided with soffit vents,and continuous air flow allowed to the ridge line.The problem is that on many older homes this intake and unobstructed air flow may be very difficult or almost impossible to achieve.older style metal ridge vents were notorious for sucking in snow and rain,but I have yet to see this problem with the improved baffle designs of capover vents such as coravent.I still find tons of pod vents and sbv's letting in rain,snow,birds,and bugs.In my climate(N.E.Ohio) the cap over vents work well. Your climate and installation may be different.Good Luck,Stephen.

1. 
   Guest_ | Jun 05, 1999 02:31am | #6

   *Fred L, Good to talk to you again. Will a cigarette work for that test?I am not gonna question your science on this cause I know you got a lot of facts on your side.I do think ,however, we may be comparing apples and oranges on this. I have found a lot of ridge vents ,without allowance for air intake,leaking.(especially the old metal style. A locally famous case was a roofing suppliers warehouse It was often a real laugh to go there in the rain and find water pouring in the ridge vent.Like the cobblers kids going without shoes).I have yet to find this situation occuring with Coravent IF the air intake was provided.I also note that most manufacturers tell us to make sure the air intake is at least 24" below the ridge line or a vacume can be formed inside the attic sucking in rain and snow.Now I fully admidt I have yet to try your test,but I have very closely observed my own shop roof which was built specifically for this type of venting andI have been impressed with visual checks so far.It has behaved exactly as I was expecting.In summer ,visually ,the heat waves pour out of the ridge vent like a smoke stack. Many ,many times the rate of the rest of the roof.This was not the case on the previous structure.In winter I note that the snow melts off of that area many times as fast as elsewhere on the roof,and very differently than on the previous structure.I very much suspect that the size,shape and pitch of the roof affect the working of the ridge vent.Also proximity of neighboring strucures and trees.(I do know for sure that different trees affect the life span of shingles at different rates)I suspect you may be implying that under different weather conditions air may enter at the ridge and exit at the soffit.Assuming that the newer baffle designs prevent this reverse air flow from bringing in rain and snow, would this be the worst thing in the world?Remember that these are just my observations,in my neck of the woods.I don't know the physics behind it all and would hesitate to trust physics since after all we know that water doesn't always run downhill.My life would sure be simpler if it did.Thanks for the suggestion,Good Luck,Stephen

2. 
   Guest_ | Jun 05, 1999 02:02pm | #7

   *Okay Fred, in 100 words or less, why don't houses ned venting?I have not read much on it, and have not read the thousand posts in the other threads.I am curious though, because my current house is not vented, and is not showing any signs of stress.I have however, replaced roof ply that had seriously delaminated on an uncles house. He lived in a townhouse and had recently put blown insulation into the attic. Within two years, everyting in the attic was mildewed.Remember, my attention span is low, I'd rather just cut in the vents, than read a book about venting. After all, life is short!Besides, it's a proven sysytem. Blue

3. 
   Guest_ | Jun 05, 1999 06:02pm | #8

   *Fred L, I am glad you mentioned the vents not making a big effect on the heat of the attic,cause this is something I frequently mention to homeowners.They seem to think roof vents are going to dramatically lower their A/C costs.On my house I have a power vent controlled by a thermostat and in august it will still get smoking hot on the second floor.Perhaps the heat I see leaving the ridge vents on my shop is not an indication of air flow?I tend to view venting as for the good of the building,and inconsequential to the comfort of the inhabitants.(much the same way ,I am told, the army provides some semblance of mechanical cooling in todays tanks.... for the operation of computers,not crew comfort)How much benefit all this actually is,is endlessly debateable,and in the end probably not that effective.I did build the shop/garage with this experiment in mind for long term observations. My main point for the above posts was that I have not found this type of R.V. to leak,although I have found MANY older styles leaking.Good Luck,Stephen

4. 
   Guest_ | Jun 07, 1999 09:13pm | #9

   *Fred L, What do you think about shingle color affecting the heat in the attic?I have customers who tell me that they would like to use a certain color but they are afraid it is to dark and will make the house to hot. As a result they end up using a color they don't really like just because it is "lighter" and in their opinion cooler.I figure that since the shingle is going to heat up to 140* or so in full summer sun regaurdless of the color,shingle color will have minimal impact. The darker color may reach "operating" tempature a few minutes earlier in the day,but both colors are soon gonna be cooking at 140* and radiating that heat into the attic. I don't think color can make more than a few * difference so customer may as well use color of their choice.Am I wrong in this.Good Luck,Stephen

5. 
   Guest_ | Jun 09, 1999 06:44am | #10

   * FredL,

   It's me again, your pal. If infrared radiations is the "major" cause of attics over heating, how can color effect this heat? If infrared is at the low end of the EMS, and not in the visible light range, how does this work? Since the light absorbed or reflected is in the visible light range?

   Joseph Fusco View Image

6. 
   Guest_ | Jun 10, 1999 12:27am | #11

   *Thanks Joe, I think this is one case where your choice of terminology put what is essentially my same question on firmer scientific footing.Question no.2 many times I find older plywood decking "delaminating" with absolutely no sign of roof leaks.I am thinking( and I can easily be wrong here)that this could be caused by excessive attic tempatures.If this is the case insulation will not solve the problem and may even compound the problem. Also,perhaps moisture from within the house could cause the problem,again compounded by the insulation. A truly efficient attic venting system could dramatically help either of these situations.In one case ,I found an interior grade of ply wood was used,so I accept the obvious cause of failure. but in all other cases cdx plywood was used. What gives?(Fred, when I say "Good Luck" I mean it in the most generic sense,not necissarily work relared)90 plus degrees today,full sun,and it aint even summer yet, Stephen

7. 
   Guest_ | Jun 12, 1999 03:12am | #12

   *Fred,I'll keep and open mind on that matter. . .

   I'd like to refer you to this link. I truly hope that we can see this conversation out to it's conclusion without any of the antics of the past. In all fairness I haven't looked at the mechanics of a heated roof but, the mechanics of energy transfer I know a little some thing about.

   The radiation process is the process of transmitting energy through and by the "wave" itself, no other medium is needed. The entire EMS transmits it's energy this way. The single most predominate way that this energy is "transferred" is through conduction, when the wave collides with matter. The dynamics of this process are beyond the scope of this discussion.

   So for the most part all the energy being transferred to a roof surface is from the EMS. This is where the infrared transmissions get fuzzy. Since they are of the long wave Varity they will not be reflected as VL will and transfer there energy on contact with the roof surface. As you stated the bulk of the energy comes from here, I agree but, at this point is where we begin to diverge. The deck does become hotter due to energy transfer and does begin to transfer the heat through conduction and convection into the attic but, not through the process of radiation. If the process of radiation was event, all attics would be hot in the winter, there not.

   This being the case, "venting" would cycle the medium of transfer, air, and cause a cooling effect in the attic.

   Joseph FuscoView Image

8. 
   Guest_ | Jun 12, 1999 07:20am | #13

   *Fred,

   I have no doubt that you would get a reading in the infrared for "any" object that is warmer then the general field it occupies. The roof deck would "glow" due to EMS energy transfer to the deck, making it warmer then the surrounding area.

   In any event, attics are hot in the summer and cold in the winter if they are disconnected from the living space. To reinforce the fact that radiation is not a primary means of energy transfer within an attic space I present this for you scrutiny; The major medium within an attic is air. The transfer of energy through air is first by conduction and then by a convention current. Radiation transfer to air is extremely poor. I would guess this is by design. . . If it were good the plant would be really hot on very cold days.

   Joseph FuscoView Image

9. 
   Guest_ | Jun 12, 1999 05:02pm | #14

   *Fred,

   I'm not going to bemoan your position or the issue, If you believe this, I hope it works for you.

   I will say that simply being opposed with no real evidence could be a mistake. In my opinion your model does not work properly.

   Joseph FuscoView Image

10. 
    Guest_ | Jun 13, 1999 06:56am | #15

    * FredL,

    No doubt that your systems preform well, you take the steps necessary to ensure this. {It's your model/science I have a problem with.} The same is true for me with PBV, I take the steps to ensure that the system performs well.

    I also believe that fg is easier, quicker and cheeper to install then cells.

    Joseph Fusco View Image

11. 
    Guest_ | Jun 13, 1999 08:23am | #16

    * FredL,

    I'm sure that in open spaces you would win hands down, only problem is that about 1/6 of an average house is open space. As far as this; "If you insist that infrared radiation in attics isn't real, then we can just attribute the efficacy of cels to some other magic."I didn't say that. I said that it's conduction and convection on the inside and radiation on the outside.

    Joseph Fusco View Image

12. 
    Guest_ | Jun 13, 1999 09:30am | #17

    * FredL

    I guess the problem with my 1/6 number is that we have different averages. The average house for me is about 5000 sf. and yes 2 to 3 floors. I try and stay away from salt boxes.

    Joseph Fusco View Image

3. 
   Kristin | Jun 13, 1999 09:30am | #18

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   I am installing a new roof on a 100+ yr. farm house. Architect doing renovation plans has recommended shingle-over ridge vents, something I've never used before. Looks pretty self-explanatory. Any specific tips?