Author Topic: Roof Construction  (Read 10024 times)

Offline cvgtpc1

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Roof Construction
« on: November 08, 2014, 10:27:42 AM »
I eventually need to correctly repair a roof damaged by Yolanda.

You can look across a PI neighborhood from above and its all dark roofs and no roof venting.

Would having soffits, roof vents (ridge or spinnng vents), and painting the roof a light color keep the house cooler?

Has anybody does this and noticed a big difference?  is this just not normally done on the average PI house due to lack of knowledge or finances, or is there another reason?


Offline coleman2347

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Re: Roof Construction
« Reply #1 on: November 08, 2014, 11:05:11 AM »
I dont know why they dont do that here, money, knowledge?? Had a conversation with an engineer a couple of days ago and its one of the things we discussed.  He agreed but said its just not done here.  Air flow is why a Nipa is so much cooler than a concrete house...If I were putting a roof back, to the degree possible, I would do it just like in the states in the warmer climates..
The only thing worse than wanting to do it is not doing it

Offline JoeLP

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Re: Roof Construction
« Reply #2 on: November 09, 2014, 01:09:23 PM »
We call them "energy truces" when my dad still had his construction company.  Doesn't matter if summer or winter, you want the insulation under the "outside air".  So you put vents in your eaves, then the air goes up into your truces and out the ridge vents.  or the reverse depending on weather.  The Insulation sit's above your ceiling with no physical contact with any of the 'roof boards" to cause a physical transfer of thermal energy to the inside of the house. 

If done right, the snow in winter will stay on your roof and act as another barrier against cold.  Sorta like igloos do that with ice.  In the summer, the hot air is not trapped in the roof also, but cycles out as new, fresher, cooler air is cycled in.  Explained that to Tina when we put the room on our house and why I wanted a ridge vent.  Now our home is cooler than her families and they are looking to put in ridge vents.

I'm guessing a lot on here knew this already, but I just am breaking it down for those not in the know.
In the land of the blind, the one eyed man is king.

Offline fred

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Re: Roof Construction
« Reply #3 on: November 09, 2014, 02:22:17 PM »
These inexpensive turbo vents seem to be quite popular here now and at the rate they spin on hot days,I`d say they must work pretty good..Probably need 2 of them at least.
Still need ample ventilation through eves though to make them work well.


Offline coleman2347

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Re: Roof Construction
« Reply #4 on: November 09, 2014, 02:26:32 PM »
Fred, I had a couple of those on my house in the states...they work great...never seen them here though, where did you see them?  Thanks Lee
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Offline Art, just a re(tired) Fil-Am

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Re: Roof Construction
« Reply #5 on: November 09, 2014, 02:44:05 PM »
                                  Why Homes Need Attic Ventilation
Why Homes Need Attic Ventilation Small | Large
"Life is what we all make it to be"!
"It's always a matter of money"!
"Do on to others as they would do on to You, but do it first"!
"Different strokes for different folks"!
"Que Sera Sera"!

Offline fred

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Re: Roof Construction
« Reply #6 on: November 09, 2014, 06:35:19 PM »
Fred, I had a couple of those on my house in the states...they work great...never seen them here though, where did you see them?  Thanks Lee

The last ones I saw were in City hardware in Tagbilaran a few days ago..
Ive seen them in a few other hardware stores too though.

Offline coleman2347

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Re: Roof Construction
« Reply #7 on: November 09, 2014, 07:09:38 PM »
fred, what do they call that here?
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Offline fred

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Re: Roof Construction
« Reply #8 on: November 09, 2014, 07:20:39 PM »

Offline cvgtpc1

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Re: Roof Construction
« Reply #9 on: November 09, 2014, 10:56:29 PM »
Fred, I had a couple of those on my house in the states...they work great...never seen them here though, where did you see them?  Thanks Lee

I think i saw them in the Home Depot in Tacloban but is that place still standing?

Offline ronnsb

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Re: Roof Construction
« Reply #10 on: November 09, 2014, 11:23:33 PM »
As a building inspector and building contractor here in Florida, I mostly see ridge vents and off ridge vents for exhaust and soffit venting for intake.

The general calculation is 2% of your attic area needed for venting. So a 1,000 square foot attic area would need 240 square inches of NFVA (net free vent area). This includes both intake and exhaust venting.

I rarely see "turbine" type vents here. They don't last that long and you will never see them on new homes. Solar power vents work good, but are way too pricey!

Always use the provided screws (similar metal) with ridge vents and never nail! The nails, being dissimilar metal will corrode.
Ron in New Smyrna Beach, Florida

Offline BudM

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Re: Roof Construction
« Reply #11 on: November 09, 2014, 11:58:42 PM »
NFVA (net free vent area).  I never fail to amaze myself how I do not know everything and learn something new every day.  Now, let me go take some measurements and then convert the square foot attic area into square meters to figure out and convert to the square inches of NFVA I would need for it to work. No, it is almost midnight right now.  Will have to do it tomorrow.

Seriously though.  It is good information that I did not know.
Whatever floats your boat.

Offline Art, just a re(tired) Fil-Am

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Re: Roof Construction
« Reply #12 on: November 10, 2014, 12:34:52 AM »
I see vents all around our concrete tile roofing under the eves if that's what they're called, but I don't know anything about NFVA (net free vent area) or if our attic has adequate ventilation, but I never thought about it until this topic came up on here! I won't lose any sleep over the thought of it though, because it's already a done deal with our home when our developer/contractor finished building our house 15 years ago!   
Besides, our roof has survived many a hurricanes in the past 15 yrs living in our home all year round! "Knock on wood"!  :o ;)
« Last Edit: November 10, 2014, 12:45:12 AM by Art, just a re(tired) Fil-Am »
"Life is what we all make it to be"!
"It's always a matter of money"!
"Do on to others as they would do on to You, but do it first"!
"Different strokes for different folks"!
"Que Sera Sera"!

Offline coleman2347

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Re: Roof Construction
« Reply #13 on: November 10, 2014, 01:37:59 AM »
In the states, I had the same thing Fred was talking about, two of them, 60x40 attic.  But what I also had was an attic vent fan on a thermostatically controlled switch, that turned it on and off based on attic temp.
I also had a whole house fan, vented directly to the attic, when I was really hot and I didnt want to run the ac I just turned that on....will do the same here if I can find, if I dont go with concrete roof...
The only thing worse than wanting to do it is not doing it

Offline ronnsb

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Re: Roof Construction
« Reply #14 on: November 10, 2014, 11:14:03 AM »
Bud...hahaha! Its easier than that. 2%..thats it! Actually easier in metric!

Art...I'm sure your roof is well vented.

Lee...those whole house fans are awesome!

Another note...if you have vents on your gable you don't need roof vents.
Ron in New Smyrna Beach, Florida

 


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