Living In The Philippines Forum

Itís Your Money => Building in the Philippines => Topic started by: cvgtpc1 on November 08, 2014, 10:27:42 AM

Title: Roof Construction
Post by: cvgtpc1 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?

Title: Re: Roof Construction
Post by: coleman2347 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..
Title: Re: Roof Construction
Post by: JoeLP 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.
Title: Re: Roof Construction
Post by: fred 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.

(http://asymptotia.com/wp-images/2008/01/roof_vent_spin_thing.jpg)
Title: Re: Roof Construction
Post by: coleman2347 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
Title: Re: Roof Construction
Post by: Art, just a re(tired) Fil-Am on November 09, 2014, 02:44:05 PM
                                  Why Homes Need Attic Ventilation
Why Homes Need Attic Ventilation (http://www.youtube.com/watch?v=3Nfvax0Ul5g#)
Title: Re: Roof Construction
Post by: fred 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.
Title: Re: Roof Construction
Post by: coleman2347 on November 09, 2014, 07:09:38 PM
fred, what do they call that here?
Title: Re: Roof Construction
Post by: fred on November 09, 2014, 07:20:39 PM
fred, what do they call that here?


Seems they call them "roof ventilators".
http://www.lulusoso.com/products/Philippines-Roof-Ventilator.html (http://www.lulusoso.com/products/Philippines-Roof-Ventilator.html)
Title: Re: Roof Construction
Post by: cvgtpc1 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?
Title: Re: Roof Construction
Post by: ronnsb 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.
Title: Re: Roof Construction
Post by: BudM 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.
Title: Re: Roof Construction
Post by: Art, just a re(tired) Fil-Am 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 ;)
Title: Re: Roof Construction
Post by: coleman2347 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...
Title: Re: Roof Construction
Post by: ronnsb 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.
Title: Re: Roof Construction
Post by: coleman2347 on November 10, 2014, 12:02:23 PM
One thing while we are on the topic of roofs...after the storm, I was noticing that most of the roofs that survived with little damage were Mansard style roofs....what they call here, four corner roofs....95% of the roofs that survived were of that type. No gables so harder to vent...but much less susceptible to wind damage.
Title: Re: Roof Construction
Post by: graham on November 10, 2014, 01:23:12 PM
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...

Lee,

My roof will need replacing soon. Gal. Iron. For 2+ years I have
been struggling with the idea to do it in concrete. I have decided
to redo with G.I. The reason: I have a mate that lives just along
the beach from me. He has a huge 3 story house with concrete
over various rooms. The house is very open, no wind stopping
doors/walls. All open plan.

When we are on the ground floor where the billiard table is, it is
open on 1 side and big arches on the opp wall. He had to buy one
of those industrial fans (30"?),  because it got so hot whenever
there was no breeze.

I have no soffits, my roof trusses sit on top of the external walls and
there is a gap of approx. 12" between the walls and the G.I. very rarely
does it get hot in the house. The trusses extend out approx 30" past the
walls. I think that's why my roof has not been taken off by the last
3 typhoons, no pressure build up between ceiling and roof. My roof is
a "Mansard" type. We call them "hip" roofs in Aussie.

If anyone could afford the electricity and water, we have, in some of the
hotter climates (40+ deg.) houses that have mounted on the roof peaks,
something similar to a sprinkler you would use in the garden. The houses
have no guttering and the water falls from the roof past windows and doors,
which changes the humidity, thereby cooling the house.

Graham

Title: Re: Roof Construction
Post by: coleman2347 on November 10, 2014, 01:31:54 PM
Graham, would it be possible for you to post some pictures here of your roof design, I think I got it but a couple of pictures would help...thanks for the ideas..Lee
Title: Re: Roof Construction
Post by: graham on November 10, 2014, 02:15:46 PM
Lee,

I'll give it a go, always have trouble
posting pics. Haven't done it for soo long now.
I'll have to find my photobucket account,
it's probably been repossessed LOL

I did have a signature etc. but one day it just
all disappeared, so didn't bother to fix it.

Graham
Title: Re: Roof Construction
Post by: ronnsb on November 11, 2014, 12:26:26 AM
Lee...here in the states that would be called a hip roof. A mansard style roof is generally along the upper exterior walls with the main roof being flat.

Hip roofs are the way to go for exactly the reason you saw...they will survive much better than gable roofs. Glad you pointed that out about what roofs survived Yolanda.

I can't even imagine what you had to go through with Yolanda! I know it was a very horrific experience.
Title: Re: Roof Construction
Post by: Art, just a re(tired) Fil-Am on November 11, 2014, 12:38:36 AM
One thing while we are on the topic of roofs...after the storm, I was noticing that most of the roofs that survived with little damage were Mansard style roofs....what they call here, four corner roofs....95% of the roofs that survived were of that type. No gables so harder to vent...but much less susceptible to wind damage.
Lee,
That is a good observation, because we have the hip style roof made from concrete roofing tiles and have withstood every hurricane that came our way dead on with the eye of the storm!
Our home is now 15 yrs old and has had a 3rd paint job. 
Hurricanes are scary to sit it out, but we survived them all that came our way! "Knock on wood"!
Title: Re: Roof Construction
Post by: coleman2347 on November 11, 2014, 12:38:50 AM
Lee...here in the states that would be called a hip roof. A mansard style roof is generally along the upper exterior walls with the main roof being flat.

Hip roofs are the way to go for exactly the reason you saw...they will survive much better than gable roofs. Glad you pointed that out about what roofs survived Yolanda.

I can't even imagine what you had to go through with Yolanda! I know it was a very horrific experience.

Ron thanks for pointing that out, you are absolutely correct its a hip roof.  I had always called that roof a mansard and stand corrected..thanks...somewhere here I have a picture of a house that was left standing after the storm, everything around the house was gone..just friggin gone.  all the neighbors houses, concrete fences..cars trucks everything..In the middle of all this devastation was one house..poured concrete, hip roof....I went and looked as close as I could because Mike and I both were amazed,  the house lost the windows on the wave side, some gutter on the wave (sea) side but otherwise was untouched...I would guess the house was about thirty to forty meters from the beach.  The wave created by the storm surge was documented to be about 30 feet or about nine something meters.  And as we all know, the winds were about 200mph...
Title: Re: Roof Construction
Post by: coleman2347 on November 11, 2014, 12:46:43 AM
Hip roof
http://en.wikipedia.org/wiki/Hip_roof (http://en.wikipedia.org/wiki/Hip_roof)
Title: Re: Roof Construction
Post by: hitekcountry on November 11, 2014, 01:04:44 AM
This is what I always thought to be a mansard roof
Title: Re: Roof Construction
Post by: ronnsb on November 11, 2014, 05:29:45 AM
Lee...wow! 30 feet...thats a lot! We have never had anything even close to that here in the Daytona Beach area. Sure, a few hurricanes here and there, but nothing more than about 110 mph. Yeah, the photos are hip roofs!

hitekcountry... most definitely a mansard roof there!
Title: Re: Roof Construction
Post by: Shewmake on November 11, 2014, 08:00:22 AM
When we built our bungalow. I did a little research and came across this website (there are many), and found it helpful. Our roof is a hip roof style which many of these sites say is the best for typhoon prone areas, with minimum of 22-26 degree pitch. Worth a look.

http://www.ndmindia.nic.in/techadvgroup/rvs/cyclonearchitecture.pdf (http://www.ndmindia.nic.in/techadvgroup/rvs/cyclonearchitecture.pdf)
Title: Re: Roof Construction
Post by: fred on November 11, 2014, 08:17:46 AM
When we built our bungalow. I did a little research and came across this website (there are many), and found it helpful. Our roof is a hip roof style which many of these sites say is the best for typhoon prone areas, with minimum of 22-26 degree pitch. Worth a look.

[url]http://www.ndmindia.nic.in/techadvgroup/rvs/cyclonearchitecture.pdf[/url] ([url]http://www.ndmindia.nic.in/techadvgroup/rvs/cyclonearchitecture.pdf[/url])


That roof definitely makes sense for high winds..You can just see it does!! Nice job.
One major consideration I had when we built ours was a large eves.. Large enough to shade walls from dawn till dusk.
Hollow blocks are like heat storage batteries..The problem is that the heat from them is released to the interior at night..
Here`s a site I discovered that gives another perspective in helping solve that problem..
(http://www.smarterhomes.org.nz/typo3temp/pics/718f6f0405.jpg)
http://www.smarterhomes.org.nz/design/passive-cooling/ (http://www.smarterhomes.org.nz/design/passive-cooling/)

Of course for those that have lived through Yolanda,their roofing plans and priorities will be different and understandably so..
If I lived there after seeing the aftermath in pictures,nothing less than an underground concrete bunker would good enough for me.
I`m actually going to build one here in Bohol. Yolanda was at first predicted to hit us directly.. There is always a chance that the next one will..
Hopefully we will be ready for it!
Title: Re: Roof Construction
Post by: ABCDeVil on November 18, 2014, 05:54:33 PM
Just a thought. If you added roof ventilation, or as we call them in Aus, whirlybirds, would they be more effective if you also added vents to the ceilings or each room. Would this also draw in more air and help cool the house inside, even more?

ABC
Title: Re: Roof Construction
Post by: medic3500 on November 18, 2014, 07:19:50 PM
Just guessing that the Roof vents (spinning type) would suck in rain during some of the more heavy downpours.
Title: Re: Roof Construction
Post by: coleman2347 on November 19, 2014, 03:30:23 AM
Dan, I never noticed that the ones I had in the states did that and we usually got a couple or more hurricanes a season. I think the reason was I have vented gables and during storms the wind would pressurize the attic, just a guess though
Title: Re: Roof Construction
Post by: medic3500 on November 19, 2014, 08:22:54 PM
Sounds good to me, I'm totally ignorant on the subject matter. 
Title: Re: Roof Construction
Post by: ronnsb on November 20, 2014, 12:07:11 AM
Fred...While it helps the energy efficiency to have the larger eaves, it works against the building structurally by creating more of an uplift area. Structurally, the smaller the eave the less uplift. Too bad there isn't a happy medium!

ABC...Sounds logical, because you are providing more ventilation to move the heat up and out.

Dan and Lee...You are right Lee. It is something like that, because there is not much air flow in an attic during a heavy downpour.
Title: Re: Roof Construction
Post by: Shewmake on November 20, 2014, 03:35:10 PM
I think the reason was I have vented gables and during storms the wind would pressurize the attic, just a guess though

Lee, could you amplify that statement-- I am dense? We have vented eaves, but no gables-- it that the same principle. I had thought of installing a exhaust blower in the attic, but the size and power requirements didn't seem to justify the return.
Title: Re: Roof Construction
Post by: coleman2347 on November 21, 2014, 12:40:28 AM
Stephen, the guy that built my house in NC, had regular gables on the front of the house not the fake ones you see so much, these gables on the front had windows.   The gables on the back on the house, had vents where the windows would normally be straight to the attic.  It seemed to work pretty good, as the attic had great ventilation. 
Title: Re: Roof Construction
Post by: cvgtpc1 on November 21, 2014, 12:52:16 AM
Lee, I think this is what you're talking about.  Read on another PI website you need to be careful which direction your house sits in as the prevailing winds will blow rain into your attic.



Title: Re: Roof Construction
Post by: coleman2347 on November 21, 2014, 01:06:48 AM
now Im confused, we had three of the window type on the front that actually let light and air into the bedrooms up stairs.

In the back they didnt go into the bed room just into the attic...the house was what is commonly called a story and a half.

This was achieved by having a very steeply pitched roof, I would post a picture but lost them all when my second hard drive crashed....
Title: Re: Roof Construction
Post by: cvgtpc1 on November 21, 2014, 01:11:31 AM
I think its all the same concept, yours were just more decorative.
Title: Re: Roof Construction
Post by: hitekcountry on November 21, 2014, 12:40:36 PM
now Im confused, we had three of the window type on the front that actually let light and air into the bedrooms up stairs.


Lee -- Are you talking about Dormer Windows?
Title: Re: Roof Construction
Post by: coleman2347 on November 21, 2014, 12:55:54 PM
now Im confused, we had three of the window type on the front that actually let light and air into the bedrooms up stairs.


Lee -- Are you talking about Dormer Windows?


exactly that....
Title: Re: Roof Construction
Post by: Shewmake on November 21, 2014, 01:43:50 PM
Okay, now I am with the program. :)
Title: Re: Roof Construction
Post by: andromeda on January 19, 2016, 05:28:31 AM
while everyone is talking about roof here, I have a delimma about cost of replacing roof. I have this 2100 square ft home in Tagaytay. I have one quote so far to completely replace the roof with shingles which is what I have now. For complete installation, roof framing, exterior painting, materials and labor... basically brand new roof altogether for 1.7M pesos. I thought that was a bit more than what it would cost a roof replacement here in US. I suppose if I'm getting tile roof then it might be close to that but I just want a shingle roofing. Does anyone have any idea how much it would cost to replace a shingle roof there in the philippines particularly in Tagaytay? thanks
Title: Re: Roof Construction
Post by: mikbal on January 21, 2016, 03:48:57 AM
   Is it a single story dwelling?

Title: Re: Roof Construction
Post by: Art, just a re(tired) Fil-Am on January 21, 2016, 06:05:33 AM
andromeda.

Is that your home that you were renting out to JJ, a member
on here? What say you JJ, does her house need a new roof?

JJ,

What is the cost of your roof of your new home you are having
built there in Tagaytay?
Title: Re: Roof Construction
Post by: Art, just a re(tired) Fil-Am on January 21, 2016, 07:12:12 AM
We have the cement roofing material on our home
since 1999 and still in good condition after 15 yrs
Also withstood two hurricane direct hits in the past
without any damage!

http://www.youtube.com/watch?v=a_zupL_FYd8
Title: Re: Roof Construction
Post by: conchydong on January 21, 2016, 09:43:21 AM
Andromeda, that price sounds  expensive for the Philippines. Yes, it might be in line with prices in the states for a tile roof, not shingle roof, with a enforceable warranty but I doubt you would get any guarantees that can be enforced in the PI. Shop around a little more would be my opinion. Good Luck with your quest.
Scott
Title: Re: Roof Construction
Post by: andromeda on January 25, 2016, 04:26:41 AM
Thank you Scott...I thought it was a bit steep. I am going to shop around when I get there.

Art...it is the same house that JJ is renting from me.

Mikbal...it is a two story house.

If I will end up spending about 38K usd to replace a roof alone, I might as well sell it as is and have one built or purchase something else.
Title: Re: Roof Construction
Post by: jjcabgou on January 26, 2016, 07:35:11 PM
I dont want to get in the middle of he said she said for one, I like and respect you both, and two, its not really my business and/or place to have asked  BUT, I did ask the contractor the other day and the price he told me he quoted you was almost half what you posted.  Are you sure what he quoted you for the roof did not include other work?