Spinners or vents for roof?

[john70t]

I have plenty of attic insulation but the existing ridge vent/soffits are not cutting it.

It's way too hot in the summer on the 2nd floor.
Paint is peeling on the access portal which indicates water condensation.

The roof is about a 30'x30' area with a 7:12 pitch.

My neighbor has the same with six covered vents facing downwards.
My concern is that the prevailing winds blow in from that side.

[GH85Carrera]

When we got our new roof we just did the ridge vents. It is about the same as when we had the old two power vents using electricity once the attic was 100 degrees. The spinning vents work great, but finding one that is of good quality is a real challenge now days. Most are made in China garbage and the bearings are just a cheap bushing that wears out in a year or two. Nothing more fun than hearing squeak squeak squeak all night while trying to sleep.

So pay the money and step up to one with a real ball bearing design. Good luck on finding the good ones, most are the chinesium garbage.

[masraum]

Assuming you have a long enough run, ridge vents are supposed to be the best (compared to a turbine). If you've got a hip roof, it seems to me that may severely limit the length of your ridge vent.

You may want to insulate the back of your access door. I did that with some of the foam sheet, and you could tell a difference afterward just walking under/past the door.

Do you have enough soffit venting for the ridge vent to keep up with? Has the soffit vent been blocked by insulation?

I think a powered vent, solar or otherwise would be a good option in certain environments.

[stevej37]

When they built my garage (26X40)..they used a formed fibrous ridge pad. Ridge shingles go on over it.
Seems to work fine.

[Bob Kontak]

Originally Posted by masraum

Do you have enough soffit venting for the ridge vent to keep up with? Has the soffit vent been blocked by insulation?

My house in Houston had zero soffit vents but several roof vents, including a spinny one.

Bought about $20 worth of sixty five cent (1996) rectangular soffit vents and went to town.

Main reason I'm posting this is when I cut the hole for the first one and the wood piece dropped out, the suction pulled the falling sawdust back into the attic.

[john70t]

Originally Posted by masraum

If you've got a hip roof, it seems to me that may severely limit the length of your ridge vent.

Good call thank you. It's a gable roof. I should have mentioned that before.

Soffit inserts are between every rafter so that should be good.
About 9-12" of spray foam floor is wrapped up to the bottom of each soffit.

The access cover has about 9" of hard foam and set inside a box well between joists. Foam tape on the seat area.
It has a tight fit but maybe not tight enough.
Maybe it needs a cap to overhang the edges and drip condensation away. IDK. There shouldn't be condensation.
I used metallic tape around the sides to help it move.

[wdfifteen]

Originally Posted by john70t

Paint is peeling on the access portal which indicates water condensation.

How does it get cold enough for water to condense on it?

[ted]

seen these vents on many new roofs.
https://ohagin.com/products/

[masraum]

Originally Posted by Bob Kontak

My house in Houston had zero soffit vents but several roof vents, including a spinny one.

Bought about $20 worth of sixty five cent (1996) rectangular soffit vents and went to town.

Main reason I'm posting this is when I cut the hole for the first one and the wood piece dropped out, the suction pulled the falling sawdust back into the attic.

Wow, interesting. I've heard that you have to have fairly balanced top/bottom venting (ridge/whirly to soffit), and it makes sense, but I think it's cool that your anecdotal experience backs that up in spades.

Our current home has 2 turbines and absolutely 0 soffit venting. Our soffits are 3/4" TnG wood. I have been assuming that I'd need to do something to fix the situation. I guess your experience is proof positive.

[red-beard]

I went through this about 10 years back. We had ridge vents and plenty of soffit. The problem was we have a HUGE southern exposure. I wanted turbines to replace the ridge vents. They arrived with powered vents.

1. Powered vents require power
2. Powered vents have motors with a limited life
3. They use thermostats that have a limited life
4. They require being properly hooked up to power!!!

At 60 Watts each, running about half the time, year round 4380 hours, using three powered vents, my estimated power bill was $75-80/year. They lasted about 3 years before failing.

About 7 years ago, I had them replaced with what I had originally wanted: Turbine vents. They do not require power. They work. I ended up with 4 turbine vents including one in an area above the bedroom.

I think at least one or two of the electric vents had failed a while before. The attic is much cooler now. And we went with commercial grade with proper ball bearings, not Home Depot level.

Oh, and I'm saving $75 per year from my electric bill. Not HUGE but still everything helps.

We will see how the new Air Conditioners perform this year. Last year, we saw a significant difference.

Now I need to attack my file servers. My estimate is they are about $25/mth of my electric bill.

[red-beard]

Originally Posted by masraum

Wow, interesting. I've heard that you have to have fairly balanced top/bottom venting (ridge/whirly to soffit), and it makes sense, but I think it's cool that your anecdotal experience backs that up in spades.

Our current home has 2 turbines and absolutely 0 soffit venting. Our soffits are 3/4" TnG wood. I have been assuming that I'd need to do something to fix the situation. I guess your experience is proof positive.

Most likely it is pulling the air into your attic from the house. Open them soffits!

[LWJ]

My roofer has added a boat load of vents on the last two houses he did for me. He says that this was a huge mistake in prior construction and that venting cures a ton.

FYI, I am in Oregon and it is very mild climate here.

I agreed with his logic, however.

[MBAtarga]

Turbines or other vents installed too high on a roof with ridge vents can circumvent the purpose of the ridge vents. I'd investigate further before cutting holes and mounting/installing anything else.

[john70t]

Originally Posted by wdfifteen

How does it get cold enough for water to condense on it?

The attic is unheated. The attic floor is insulated with foam. Everything below that is part of the interior "thermal envelope" and conditioned by the central heating/cooling system.

My newer furnace should be removing excess interior humidity both summer and winter...when it's run...but I suspect a small amount of warm humid air is getting past the ceiling access port seal. Need to fix that as well.

Wherever warm and cold air/surfaces mix, a localized dew point is created and water condenses.

It's like filling up a cold toilet tank when it starts sweating and dripping pools on the floor.
The ground water for the first floor toilet is colder and that's where it occurs first.

[Tidybuoy]

I don't have a great picture but I installed a full length ridge vent and it works great. It consists of a plastic vent that fits the entire length of the roof. Prior to installing, a 1-2" cut is made into the top most shingles & roof exposing a 1-2" gap (you will be able to see into the attic). After that, the plastic ridge vent is installed, after that, ridge shingles are installed on top of the vent. The open gap is from end-to-end of the roof except 2' on each end. When all done, I had a 70' vent which is virtually invisible.

During the summer, if you go into the attic, it sounds like a big wind storm up there as the air is blowing straight up and out.

This is the only photo I have here at work and this is as I just started installing.

Photo showing plastic ridge vent with a few ridge shingles nailed to it - just starting:


Photo below is "before" gap is cut into ridge:

[john70t]

^There's not much space for all that hot attic air to squeeze through on a 110deg day.
(read: Volume)
Plus the ridge beam is located right there.

Same situation here.

[pmax]

Originally Posted by john70t

I have plenty of attic insulation but the existing ridge vent/soffits are not cutting it.

It's way too hot in the summer on the 2nd floor.
Paint is peeling on the access portal which indicates water condensation.

The roof is about a 30'x30' area with a 7:12 pitch.

My neighbor has the same with six covered vents facing downwards.
My concern is that the prevailing winds blow in from that side.

Spinners ? You meant turbines or whirly birds

How many were installed ? One every 8-10 ft or so is what I have but then this is NorCal.

[masraum]

Originally Posted by john70t

^There's not much space for all that hot attic air to squeeze through on a 110deg day.
(read: Volume)
Plus the ridge beam is located right there.

Same situation here.

I thought a ridge vent is supposed to be one of the best sorts to install. If he had 70' of vent that was 1-2" wide, that's 840sqare inches of vent if it was only a 1" wide vent which is 5 5/6 sq ft. If the slot was 2" then it would be 11 2/3 sqft. I guess if it was just 1" then that doesn't sound like enough, but I would think 2" should have been plenty.

[john70t]

The photo above to my poor eyes looks like a 1" slot...to expel heated air from a large space on a warm day without wind.
A darker roof in Texas none the less.

Sunshine-state provided materials sold in box store should be appropriate for the proper application. imo,
People should have information.

Over-engineering a small but very crucial thing such as a roof for a few bucks more should never be an issue, in the long run.

[Tidybuoy]

Originally Posted by john70t

^There's not much space for all that hot attic air to squeeze through on a 110deg day.
(read: Volume)
Plus the ridge beam is located right there.

Same situation here.

The photo that I posted is before I cut the 2" opening for the air passage. Yes, the ridge beam is right there but I am cutting only the sheathing which left a decent slot for the air to escape. I just didn't take detailed photos at the time. What is showing is just the edge with everything sitting in place but not yet nailed down.