And now.. Roof vents questions

[Deschodt]

It's home improvement week, at Casa de Greg.

I've recently found out that I did not have roof vents of any kind...For shame, in FL, a 10y old house, somebody must have bribed a home inspector! The attic is frequently seeing 125F or more, and that makes my upstairs A/C work overtime !

No biggie I thought, I'll have some installed... Concrete tile roof, no big deal,pop 2 tile, put a vent, reseal? Well I have had 2 quotes so far and not one under $4500 ! Gulp ! That's for a couple of thermostatic vents ?!

I want to know if that is "I dropped the soap, why don't you pick it up?" kinda pricing
or if it's just me not being up to date on what it costs... Also doubting I need fancy thermostatic anything, just a hurricane proof hole ! At that price, it would take a looong time to get my money back in A/C savings...

Opinions? Am I getting the stupid price or am I out of touch ?

[Edit] PS: I just read this online:

"my roofer says we dont need attic ventilation with a concrete tile. He says tile roofs are cooler then shingles like we had before. The tile insulates. 99% of all the tile houses I see in the area have no roof top vents or power vents. The only rooftop power ventilators I can find in the stores are made for shingle roofs."

I wonder then if 125F under my tiles is considered OK or not ? Seems high to me. When the A/C breaks down, downstairs equalizes with outside temps within a couple of hours, upstairs remains 10-15F hotter for hours and hours !

[VINMAN]

Regardless of the type of roof you have, you still need some kind of airflow out of your attic. 1.To dump the heat. 2.To get rid of moisture.
You can always install high gable end vents with fans. Do you have soffit vents?

Dont know what the pricing is in your area but that seems way steep.

[Deschodt]

I agree, seems odd to me but I am no expert... Moisture is not an issue with those temps, trust me, but heat is ;-) No gable neds possible, the roof "drops" on every corner - for lack of a better word...

Yes on soffit, but if I understand convection, soffit is good for letting cooler air IN, but the hot air goes UP and you need to vent it at the rigde or close to it...
BEsides the soffit are under 2 ft of insulation, so I need to go up and "rake" the insulation off the edges ! Wish me luck ! ;-)

[VINMAN]

Venting at the highest point is preferable . I like ridge vents the best. But if you cant do that the gable vents right at the peak is the next best thing. (assuming you have gables on the house)

[911Rob]

Forget the thermostat controlled venting.

Do you have continuous soffit venting?
If you have the soffit venting, pop some screened vents from Home Depot into the gable ends at the highest point possible. Simple, easy and will help the air flow for sure.

edit: sorry, I realize our man Vin has this covered already; so good luck.
and yes, you must have the soffits free of insulation. You can buy a foam insulation stop to insert between the trusses.

[looneybin]

Originally Posted by Deschodt

the roof "drops" on every corner - for lack of a better word...

you have a hip roof

there is a nice roof vent called "stealth vent"
it's made by O'Hagin's
www.ohaginvent.com

they blend into the roofing material

you should be able to lap them into the existing tiles

[Heel n Toe]

Originally Posted by Deschodt

....the soffit (vents) are under 2 ft of insulation, so I need to go up and "rake" the insulation off the edges ! Wish me luck ! ;-)

Before you do that, give this a try... I've never done it, but it seems plausible; from outside, hit those vents with your leaf blower. Put the tip right on the vent and move it back and forth for 10-15 seconds. Maybe have someone with their head in the attic looking for the insulation to blow up and away.

If it's powerful enough, it should do the job. Let me know if it works for you.

[Deschodt]

Originally Posted by Heel n Toe

Before you do that, give this a try; from outside, hit those vents with your leaf blower. Put the tip right on the vent.

If it's powerful enough, it should do the job. Let me know if it works for you.

That's actually a great idea, but not all that practical in my house, it's 2 floors high but with real high ceiling, it adds up to a deadly fall... I'd need a VERY tall ladder and I would probably kill myself trying to hold on with one hand and hold the leaf blower with the other ! ;-)

No, it's gonna be 125F and a rake for Greg ! ;-( worst case I'll fall through the ceiling ;-)

PS: Looney, thanks for the Ohagin tip, I've actually been there first and that was a $6000 quote.. I kid you not !

[Racerbvd]

Originally Posted by 911Rob

Forget the thermostat controlled venting.

Do you have continuous soffit venting?
If you have the soffit venting, pop some screened vents from Home Depot into the gable ends at the highest point possible. Simple, easy and will help the air flow for sure.

edit: sorry, I realize our man Vin has this covered already; so good luck.
and yes, you must have the soffits free of insulation. You can buy a foam insulation stop to insert between the trusses.

I'm currently having my house painted and am adding some gable vents & attic fan...

[dad911]

Originally Posted by Deschodt

......
BEsides the soffit are under 2 ft of insulation, so I need to go up and "rake" the insulation off the edges ! Wish me luck ! ;-)

There is a Styrofoam product for this, that slides in between the insulation and the bottom of the roof, to allow airflow. Shaped like a continuous 'W'

http://www.owenscorning.com/worldwide/admin/tempupload/pdf.30011372.pdf
http://www.acehardwareoutlet.com/(g35lqe55szrwrz55ljj43eq1)/productdetails.aspx?sku=5401542&source=GoogleBase

[dad911]

FYI, just looked it up in national building code:

Enclosed attics (and rafter space, like a cathedral ceiling) require cross ventilation. 1 square foot of ventilation for every 150 sq. feet of attic.

This can be reduced to 1 foot per 300, with 50-80% of the ventilation up high near the ridge, and the balance at the eaves/soffit.

Insulation shall not block the free flow of air. Minimum 1" space between insulation and roof sheathing.

Greg, just noticed your edit. I have no experience with clay tile, not used much in this neck of the woods. However, the 'national code' does not change ventilation requirements, just addresses fasteners for clay tile.