Fascia/Eaves on newly constructed house

[AlbionThailand]

The wife and I have just complete the building of a 2nd home.  We designed it and had it built to our specifications.....almost!

In the area where the roof tiles hang over the eaves (arrow on the attached image), I wanted no fascia board, just a decent gap to allow ventilation. 

Instead of fascia boards, there would be some mesh to avoid nasty critters entering the roof but still allowing a decent breeze in the attic area. 

I also wanted to install some ducts in each of the 1st floor rooms to allow heat to rise and escape.

When I was on a trip, the builder thought this was a hare-brained idea and abandoned it. 

Would I see any noticable reduction in interior house temperature if I did this?  Would appreciate advice.

[BJM1950]

It's no good putting vents in the facia if there is no where for the hot air to get out. In Aus, we call them a 'whirly bird', spinning ventilator. Put a few on the backside of the roof near the apex to let the hot air out. make sure they are flashed properly, you don't want leaks!

[irlguy1]

Mesh won't stop mice and snakes and bugs. Leaving the gap won't make it any cooler and without that fascia board when it rains heavy with some wind all that water is gonna blow back into the attic as it comes off the roof.



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[BJM1950]

It's a bit late now, but they could have cut out the facia for some louvered vents with mosquito netting on the back. I doubt you'd get the water blowing back like that.

[irlguy1]

It's a bit late now, but they could have cut out the facia for some louvered vents with mosquito netting on the back. I doubt you'd get the water blowing back like that.

Trust me you will definitely have the water blow back. I have seen it first hand.
It's simple physics. Water moves direction when blown. Surely you have witnessed water blowing in an open window?
Now multiply that by the gallons coming off the roof in a steady downpour plus high winds.
It's a disaster waiting to happen


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[petermik]

You can buy "eaves fillers" which are lengths of plastic with profiles matching your roof tiles,they can be bought quite cheaply at any Watsadu store,keeps the birds/rats out

[sirineou]

 The minimal advantage (if any) of the increased ventilation, does not justify the additional work, danger from criter, and water infiltration. IMO the builder did you a favor. 

[Crossy]

Since you have gables you could install louvred gable-vents with internal critter screens. One at each end and any breeze will shift air through the loft space.

 

We have these in both ends of all our roof spaces, work well.

 

[mogandave]

Looks like it has vents in the gables.

There are good wind-driven rain louvers available that will stop water penetration in 100kmh winds.

“Whole House” fans seem to be gaining popularity, these typically install in the ceiling access opening, drawing the air from the interior of the house, and exhaust out the gable vents.

[blackcab]

Moved to the DIY Forum.

[wayned]

On 8/31/2018 at 12:40 PM, petermik said:

You can buy "eaves fillers" which are lengths of plastic with profiles matching your roof tiles,they can be bought quite cheaply at any Watsadu store,keeps the birds/rats out

I have the plastic fillers, they are tacked to the large fascia and then a smaller thinner fascia is installed flush with the roof to cover the installation.  Been there for 18 years and works fine.  You have gable vents which allow the hot air from the attic to escape and it is replaced by the air that is drawn in from under the roof panels.  Do not completely close off these areas as it will actually make the house hotter since there would be nowhere where outside air could be drawn into the attic.

[kamalabob2]

The Fascia boards will be where you should consider mounting rain gutters. You have cable vents. Whole house attic fans are readily available.  Did you have ventilation soffit boards to increase the air flow in your attic. Insect netting is a crucial part of the soffit board installation. There are many styles of soffit boards which allow attic ventilation in Buriram. 

[rumak]

This may not be a well received response but here is my experience.   I have lived in a few houses here (single story).

Have tried the following :   vents in both gabled sides,  and insulation matts on the ceiling.

                                                an attic fan to help blow out the hot air

                                               foil on back of gypsum ceiling

                                               One completely open gabled side (with screen) This is the side where weather cannot enter as it has garage extension on that side

                                                

Now i know many posters swear there is a 5 or 10 degree difference with their systems, maybe so,  but everything

i do does not really make THAT much of a difference.  When that sun is hitting the roof and worse, the walls,  it is

darn hot.   Best solution yet:   small house,  good A/C  !   very cost effective  ?

 

I do find that a porch,   a tree,  something that blocks the sun from hitting the walls makes a difference for sure.  Small vents.....forget it 

 

 

 

 

 

 

 

 

 

 

 

 

Edited September 19, 2018 by rumak

[kannot]

15 hours ago, rumak said:

This may not be a well received response but here is my experience.   I have lived in a few houses here (single story).

Have tried the following :   vents in both gabled sides,  and insulation matts on the ceiling.

                                                an attic fan to help blow out the hot air

                                               foil on back of gypsum ceiling

                                               One completely open gabled side (with screen) This is the side where weather cannot enter as it has garage extension on that side

                                                

Now i know many posters swear there is a 5 or 10 degree difference with their systems, maybe so,  but everything

i do does not really make THAT much of a difference.  When that sun is hitting the roof and worse, the walls,  it is

darn hot.   Best solution yet:   small house,  good A/C  !   very cost effective  ?

 

I do find that a porch,   a tree,  something that blocks the sun from hitting the walls makes a difference for sure.  Small vents.....forget it 

 

 

 

 

 

 

 

 

 

 

 

 

He  could right from the start have done a whole  house ridge  vent, they are available here now and those gables are crying out for huge vented area to be installed.

Yes  small house, I built  with double  block  walls= very cheap with air gap, could have added  insulation also but decided  it was enough.

50m2 1  bed  kept  cool with one 10000 btu aircon, monthly  bills in hottest  months 12-1300 baht max with aircon set at 25c, rest of the year 900 baht, most important though is make sure every gap is sealed tight, i got single  pane upvc  windows with good  selas and  all my doors are almost airtight fit, when i open the front door its  hard to do due to air tightness, the ceiling creaks as  the vacuum is disturbed, same with bedroom doors, you can feel the air trying to escape the room but cant making doors  harder to open close.

Next plant trees  round the house but not  too big as  falling  branches can damage a lot of roof  tiles.

After a  few  years the house is surrounded by trees and i can hardly see it, large overhangs stopped the walls  getting hot when the trees  werent in but  now almost no parts of the walls  get sun due to foliage cover.

Roof  has  4  small chimneys ( stainless) made by local shop for any venting and eaves under  gutters  also have  vent space  all round. vents are high up this  photo just for "show"

4  inch of fibreglass in foil on all ceilings is critical if  you have aircon, 4  inch is  fine, any thicker and savings  minimal 

Edited September 20, 2018 by kannot

[rumak]

2 hours ago, kannot said:

He  could right from the start have done a whole  house ridge  vent, they are available here now and those gables are crying out for huge vented area to be installed.

Yes  small house, I built  with double  block  walls= very cheap with air gap, could have added  insulation also but decided  it was enough.

50m2 1  bed  kept  cool with one 10000 btu aircon, monthly  bills in hottest  months 12-1300 baht max with aircon set at 25c, rest of the year 900 baht, most important though is make sure every gap is sealed tight, i got single  pane upvc  windows with good  selas and  all my doors are almost airtight fit, when i open the front door its  hard to do due to air tightness, the ceiling creaks as  the vacuum is disturbed, same with bedroom doors, you can feel the air trying to escape the room but cant making doors  harder to open close.

Next plant trees  round the house but not  too big as  falling  branches can damage a lot of roof  tiles.

After a  few  years the house is surrounded by trees and i can hardly see it, large overhangs stopped the walls  getting hot when the trees  werent in but  now almost no parts of the walls  get sun due to foliage cover.

Roof  has  4  small chimneys ( stainless) made by local shop for any venting and eaves under  gutters  also have  vent space  all round. vents are high up this  photo just for "show"

4  inch of fibreglass in foil on all ceilings is critical if  you have aircon, 4  inch is  fine, any thicker and savings  minimal 

I like what you did !  I did not go to such extremes(no double wall) but same basic concept.  My electric bill around same as yours.

Do you ever check the attic at around 10 pm on a hot day to see if it is still like an oven ?   Mine always were, but my

open sided gable helps a lot now to cool down after sun goes down.   Daytime....still hot as hell up there.  Your 4"bats

should help to keep that heat from filtering down (touch ceiling during day to see if it is warm?)

Edited September 20, 2018 by rumak

[kannot]

1 hour ago, rumak said:

I like what you did !  I did not go to such extremes(no double wall) but same basic concept.  My electric bill around same as yours.

Do you ever check the attic at around 10 pm on a hot day to see if it is still like an oven ?   Mine always were, but my

open sided gable helps a lot now to cool down after sun goes down.   Daytime....still hot as hell up there.  Your 4"bats

should help to keep that heat from filtering down (touch ceiling during day to see if it is warm?)

It  will get hot in the day even with foil under the tiles and  venting, my ceilings  dont get hot as I have the fibreglass insulation, I havent been up there since I did the electrical wiring about 6 years ago and no plans to either hahahaha

For sure the venting will help a great deal, at the time the AAC blocks were quite expensive so I used the cheap  concrete blocks  doubled  up and the R value  was  higher than the single   aac's. That and the now  fully  grown surrounding foliage keeps the sun wholly off the walls.

Edited September 20, 2018 by kannot

[Don Chance]

There real problem is your porch deck. The tiles are not water proof. There needs to be a plastic underlay that prevents water from penetrating the slab - which no doubt they did not use. It will take a few year but soon the water will penetrate under your tiles in your living room and cause mold!

The other issue was a plastic vapor barrier put under the slab foundations? No doubt probably not, means wet slab and mold under the tiles.

 

[kannot]

On 9/21/2018 at 9:43 AM, Don Chance said:

There real problem is your porch deck. The tiles are not water proof. There needs to be a plastic underlay that prevents water from penetrating the slab - which no doubt they did not use. It will take a few year but soon the water will penetrate under your tiles in your living room and cause mold!

The other issue was a plastic vapor barrier put under the slab foundations? No doubt probably not, means wet slab and mold under the tiles.

 

or could have added  waterproofer into the concrete

[kannot]

On 9/21/2018 at 9:43 AM, Don Chance said:

There real problem is your porch deck. The tiles are not water proof. There needs to be a plastic underlay that prevents water from penetrating the slab - which no doubt they did not use. It will take a few year but soon the water will penetrate under your tiles in your living room and cause mold!

The other issue was a plastic vapor barrier put under the slab foundations? No doubt probably not, means wet slab and mold under the tiles.

 

 

[Don Chance]

What is that? Looks like some sort of plastic canvas carry bags. Doesn't inspire my dreams of long term water proofing but ok. Still be a good idea to have eaves trough for the water not land around the slab. Also weeping tile system.

 

As for your porch tiles they will get wet, i would apply some sort of sealant on the grouts to keep the water from penetrating.

[kannot]

On 9/28/2018 at 5:03 PM, Don Chance said:

What is that? Looks like some sort of plastic canvas carry bags. Doesn't inspire my dreams of long term water proofing but ok. Still be a good idea to have eaves trough for the water not land around the slab. Also weeping tile system.

 

As for your porch tiles they will get wet, i would apply some sort of sealant on the grouts to keep the water from penetrating.

Thats there to slow down the concrete curing, the concrete is actually waterproof  as  well.

[kannot]

On 9/28/2018 at 5:03 PM, Don Chance said:

Still be a good idea to have eaves trough

I  guess you mean guttering, I have that all round (upvc) but i think u maybe be confused with my house photos and the Op's who has none