Which Insulation Material under the Roof?

[4MyEgo]

1 minute ago, Kwasaki said:

I would say many will agree with your findings nothing wrong with that,  you have achieved what you like. 

 

You can justify them as much as you like and they are beneficial.

 

As I have said personally from architectal and aesthetic point view and the type of house design they will look ugly in many cases and there are many other alternative ways to achieve house heat insulation. 

Fortunately for me, I took in the aesthetics as you say, the whirly birds are at the very back of the house and cannot be seen from the road, e.g. we have a high covered outdoor area which blokes you from seeing them, i.e. unless you want to see them, there is one angle from under the high covered roof area that you can see one of the whirly birds so as to see if it's spinning, the other is on the rear side so cannot be seen.

 

If you asked me what I preferred, heat or whirly birds being seen by air, whirly birds win hands down.

 

In my opinion, they are a must, along with a high clearance in your roof space, Sisalation, Insulation and vented eaves, if one wanted to add the ridge vents, well that would be their personal choice, but the point I always make is that when those whirly birds get spinning they are like a vacuum sucking the hot air out, all you have to do is stand under one when it's happening and you can feel the hot air being sucked up, so I get peed off when someone says they don't work, they work better than ridge vents because they don't suck out the hot air.

[unheard]

1 hour ago, 4MyEgo said:

I get peed off when someone says they don't work, they work better than ridge vents because they don't suck out the hot air.

That's all great that you're satisfied with their "performance."

The point being made here is that for anyone else who's just considering installing whirlybirds - go online and research the subject for yourself in order to make an informed decision.

There's aplenty of available material online.

[unheard]

1 hour ago, 4MyEgo said:

If you value a more subtle look, the ridge vent wins in that category. ... Still, despite running the entire length of your roof, ridge vents are static and won't move air the same way turbines do. As long as there's a healthy amount of wind to power them, turbine vents will provide superior ventilation for your attic.Jul 21, 2564 BE

Totally disagree on the statement that "ridge vents are static and won't move air the same way turbines do."

Yes, ridge vents are static as no moving parts involved (first advantage), but they will also move an enormous amount of air by volume as compared to turbine vents. (second big advantage).

You can simply compare the dimensions of the opening provided by the whirlybird against the opening provided by the full length of vented ridge.

[Kwasaki]

26 minutes ago, unheard said:

Totally disagree on the statement that "ridge vents are static and won't move air the same way turbines do."

Yes, ridge vents are static as no moving parts involved (first advantage), but they will also move an enormous amount of air by volume as compared to turbine vents. (second big advantage).

You can simply compare the dimensions of the opening provided by the whirlybird against the opening provided by the full length of vented ridge.

Whatever you do and whatever method you use you make comparisends by taking temperatures before and after. 

 

When I insulated my upstairs bedroom ceiling in a compact way over the area the best thing apart from the air-con producing results quickly and not kicking in and out for long periods of time was the the noise level. ????

[grin]

We have a steel frame roof with concrete tile and a reflective foil under it. We also have StayCool laid on top of our suspended drywall ceilings. We have two forward facing gables so what I did was have fans installed at both gables facing outwards. I have two switches wired to each fan. One switch is wired through a thermostat and the other wired directly to the fan. That way the fan can be switched on or off or under thermostat control.

 

Last but not least we increased the number of soffit vents  in our eaves. The original plan only had about 20% of the eave area vented. We changed that to 80%. The vents are just wood slats backed by wire screens. With the large amount of soffit vents we seldom have to use the gable fans but on really hot days the fans help as well.

[connda]

We rewired the electric in PVC cable runs and installed batting at the same time.  Major improvement.  Inside temperatures stay moderate even when it's very hot or very cold outside. 
That was worth the time and expense.  I highly recommend it.

[gejohesch]

1 hour ago, connda said:

We rewired the electric in PVC cable runs and installed batting at the same time.  Major improvement.  Inside temperatures stay moderate even when it's very hot or very cold outside. 
That was worth the time and expense.  I highly recommend it.

Many thanks to you and everyone else in this discussion, even if there are a few clashes of opinions. Clearly, there are a number of things one can do to improve the cooling of the house, as advocated by all of you. Not everything has necessarily to be done together but a combination of a few seems to be the right approach. As a recap, I will do the following:

- A) install isolation batts - everyone agrees on that I think;

- B) put in place better roof sheets, with an insulation layer of 25mm (I'm worried about the extra weight on the ceiling of the 50mm option);

- C) discuss with my builder if it is reasonably practical to make the new roof 1) single pitched and 2) standing higher than the current roof. I think we could consider an extra 30 cm making the height from the ceiling to the ridge 170cm instead of the current 140cm.

- D) We already have the saloon type slatted windows in the gables. We'll consider the possibility of getting a vented ridge (we'll ask the builder) - after all, even without the vacuum effect of the whirly birds, sucking out warm air, if there is warm air under the roof, it will want to rise up anyway (that's what warm air always does, is it not?) and a vented ridge would have to be helpful in evacuating that warm air.

[sometimewoodworker]

@gejohesch 
A) yes

B) 50mm insulation is better and makes virtually no difference in weight.

C) get the recommendation of pitch required from the maker of your tiles. If you go for steel sheet you can go as low as 15^o but with tile probably 35^o is your minimum. DO NOT BELIEVE YOUR BUILDER WILL GIVE CORRECT ADVICE. He may be a Thai unicorn, but like unicorns that almost never is seen.

D) ridge vents and whirly birds are OK if you don’t get sugar cane burning or large amounts of airborne dust. If you have either of those your life will be very uncomfortable as SWMBO or SWDTC (She Who Does The Cleaning) will make clear every day exactly why you made a terrible choice. 
 

I did suggest ridge vents in my design process and SWMBO swiftly told me in no uncertain terms why we were not having them.

[gejohesch]

33 minutes ago, sometimewoodworker said:

@gejohesch 
A) yes

B) 50mm insulation is better and makes virtually no difference in weight.

C) get the recommendation of pitch required from the maker of your tiles. If you go for steel sheet you can go as low as 15^o but with tile probably 35^o is your minimum. DO NOT BELIEVE YOUR BUILDER WILL GIVE CORRECT ADVICE. He may be a Thai unicorn, but like unicorns that almost never is seen.

D) ridge vents and whirly birds are OK if you don’t get sugar cane burning or large amounts of airborne dust. If you have either of those your life will be very uncomfortable as SWMBO or SWDTC (She Who Does The Cleaning) will make clear every day exactly why you made a terrible choice. 
 

I did suggest ridge vents in my design process and SWMBO swiftly told me in no uncertain terms why we were not having them.

Thanks

[Kwasaki]

59 minutes ago, sometimewoodworker said:

steel sheet you can go as low as 15^o

In one length ridte to eaves you can as low as 5 degrees.

[spidermike007]

It sounds like you have a standard drop ceiling. We do too. We installed rolls of R-22. Just laid them flat on the inside of the ceiling. With no ventilation in the attic, it made a huge difference. It is a rental property, and would have required modifications to install exhaust vents, though I am sure that would have helped even more. 

 

Our house used to be an oven. Now, it is 3-5 degrees  cooler, everyday. It is a remarkable difference. Many days with no AC required. Cost of insulation was around 11,000, and labor was only 2,000. Worth every baht. It is like a different house now. Not only does the AC work better, the rooms stay cool for hours after they are shut off. 

[sometimewoodworker]

29 minutes ago, Kwasaki said:

In one length ridte to eaves you can as low as 5 degrees.

Right. I was being conservative, I think we have about 7.5 degrees.

[gejohesch]

7 hours ago, spidermike007 said:

It sounds like you have a standard drop ceiling. We do too. We installed rolls of R-22. Just laid them flat on the inside of the ceiling. With no ventilation in the attic, it made a huge difference. It is a rental property, and would have required modifications to install exhaust vents, though I am sure that would have helped even more. 

 

Our house used to be an oven. Now, it is 3-5 degrees  cooler, everyday. It is a remarkable difference. Many days with no AC required. Cost of insulation was around 11,000, and labor was only 2,000. Worth every baht. It is like a different house now. Not only does the AC work better, the rooms stay cool for hours after they are shut off. 

Great, thanks for your comment

[gejohesch]

A few weeks later..... Right now in the middle of the works to modify that roof and insulate better. One question comes up, in addition to all that has been said so far about roofing, insulation batts etc: what about the windows?

 

We only have a rather basic type of windows with only a thin glass pane. Double glazing tends to be unknown in rural Thailand. And it is no surprise that all those windows become like radiators, radiating the external heat into the house. Hopefully, all the roofing work will make a big, welcome difference to the heat cycle inside the house, but I'm now thinking that we could also think of improving the windows. To start with, they do not fit perfectly i.e. there are gaps around the edges (have you ever checked windows built by villagers in rural Thailand?). I have done what I could applying as much silicon as I could around the windows. Next, I'm thinking of dressing the window panes themselves with insulation film, so here is the question:

 

- has anyone got experience worth sharing with insulation films for windows here in Thailand?

[sometimewoodworker]

17 minutes ago, gejohesch said:

A few weeks later..... Right now in the middle of the works to modify that roof and insulate better. One question comes up, in addition to all that has been said so far about roofing, insulation batts etc: what about the windows?

 

We only have a rather basic type of windows with only a thin glass pane. Double glazing tends to be unknown in rural Thailand. And it is no surprise that all those windows become like radiators, radiating the external heat into the house. Hopefully, all the roofing work will make a big, welcome difference to the heat cycle inside the house, but I'm now thinking that we could also think of improving the windows. To start with, they do not fit perfectly i.e. there are gaps around the edges (have you ever checked windows built by villagers in rural Thailand?). I have done what I could applying as much silicon as I could around the windows. Next, I'm thinking of dressing the window panes themselves with insulation film, so here is the question:

 

- has anyone got experience worth sharing with insulation films for windows here in Thailand?

You have start with good frames, once you have done that you can reduce heat transfer using low-e glass. If you don’t want to get proper IGUs there are various methods from adding a second sheet of glass, using shutters etc to using bubble wrap. 
 

bubble wrap is effective (I have used it) and cheap but not pretty and is temporary.

Edited March 10, 2022 by sometimewoodworker

[gejohesch]

5 minutes ago, sometimewoodworker said:

You have start with good frames, once you have done that you can reduce heat transfer using low-e glass. If you don’t want to get proper IGUs there are various methods from adding a second sheet of glass, using shutters etc to using bubble wrap. 
 

bubble wrap is effective (I have used it) and cheap but not pretty and is temporary.

Thanks. Is adding a second sheet of glass straightforward?

[Will B Good]

We have a steel roof covered in concrete tiles and large eaves with soffits in every corner......no insulation of any kind.

 

There seems to be no method of venting the roof space.

 

Will hot air naturally vent through the overlapping concrete tiles or do I need to add whirlybirds, fans or special tiles?

[sometimewoodworker]

21 minutes ago, gejohesch said:

Thanks. Is adding a second sheet of glass straightforward?

That depends on your abilities and the existing windows. For me and wood frames it’s simple & even making supplementary secondary frames isn’t particularly difficult. You will need to ensure that you have sufficient drainage so a hermetic seal isn’t required.

[gejohesch]

Work on the roof has progressed to the point that I can now start reporting back, sthg I feel I owe to all those who contributed to this discussion a few weeks ago. A recap will also be useful to myself. It’s been quite an adventure so far!

 

Let’s start with the essence of the project: the idea was to renovate the roof of one of the 2 houses we have on my wife’s compound, in a village somewhere in rural Isan. The roof is made of metal sheets, as opposed to being tiled. The motivation was the need to improve the temperature management inside the house. Specifically, I’m talking of the heat problem familiar to anyone living in Thailand.

 

To achieve that, we did the following:

1-      Replaced the old double-pitched roof with a single pitch roof, adding to the volume between the roof and the dropped ceiling. Extra volume will improve the air circulation and reduce the heat build-up beneath the roof. I join a front view of the house showing the respective positions of the old and new roofs (Pic 1). The façade looks straight south, which means a lot of exposition to the sun.

The new roof ridge is 35 cm higher than the old one (point M). The height from ceiling to roof ridge changed from 1.8m to 2.15m.

At the house corners (points A and E), the new roof is 20 and 55 cm higher; at the old pitch change points (C and D), the new roof is 70 and 75 cm higher (left and right sides, respectively). The overall volume between the roof and the ceiling has increased from 74 to 117 cubic metres, i.e. an appreciable 60% increase.

2-      Having lifted the old roof out, we laid insulation batts over the dropped ceiling. We used SCG 6” sheets.

3-      The new roofing sheets have a 25mm insulation foam glued to the metal (the old ones were of the standard basic type seen everywhere in Thailand). We opted for a straight white colour to maximise heat reflection.

 

Before going any further, I should say that I used the Trimble Sketchup software to model the house in 3D and search for the possible modifications. I spent a tremendous amount of time measuring the house to quite some detail. The house was built by local builders with standards rather different to what one is used to in the western world. As a result, if it looks straight and square enough at first glance, in reality not much is really straight, vertical or horizontal! People with experience in rural Isan will know what I’m talking about. Nevertheless, I achieved a precision of a few cm anywhere around the house, the other house that is connected to it via an internal courtyard (our outdoors kitchen), and pretty much anywhere else around the compound.

 

One of the reasons to make a model on my laptop is that the left side of the house (point A) is very, very close to the wall that separates us from our immediate neighbour. I’m talking of cms here! I wanted to make sure the new roof would come at the right length so as not come too short and also not to reach the wall. The neighbour would certainly not be happy with water gushing out from our roof to his compound at times of heavy rain! Pic 2 is the roof model we ended with, with the individual sheets shown on the left side. That’s where the roof is irregular due to the proximity to the neighbour’s wall –neither that wall nor the house is straight!

 

I also wanted to have a good model at hand to make sure the builders would get the new roof right, with both sides pitching at the same 12 degrees angle, give or take 1 degree. I arrived at these 12 degrees because of 2 constraints : 1) the roof ridge could be moved higher than 35 cm because it comes under another existing roof which we did not want to modify (see Pic 5); 2) the roof had to arrive at about the height level of the wall separating from our neighbour.

 

The building work is now going on its 6th day, and will be completed today or tomorrow (5 men). I will give a few comments on how it progressed in following messages.

Edited March 15, 2022 by gejohesch
forgot sthg

[gejohesch]

1 minute ago, gejohesch said:

Work on the roof has progressed to the point that I can now start reporting back, sthg I feel I owe to all those who contributed to this discussion a few weeks ago. A recap will also be useful to myself. It’s been quite an adventure so far!

.......

I will give a few comments on how it progressed in following messages.

Day 1: old roof lifted out; started placing new beams and rafters.

o   Pic 3 shows the structure that supported the old roof. Note the wires hanging the dropped ceiling to the battens.

o   Pic 4: left side of the house (Point A). Note how close the house comes to the wall that separates from the neighbour. Also, this shows how flat the old roof was lying over that side of the house, meaning that heat was directly transmitted from the roof to the habitation. That was one of the main issues as our bedroom is on that side of the house (on the far side) and we often felt like living in an oven!

o   Pic 5: view from the left side to the central part of the roof (Points C and M). On the right side of the pic, you see that the roof ridge comes underneath another roof. This fixed the maximum amount by which we could move the ridge upwards. That other roof, btw, lies over a terrace built in between the 2 houses my wife has on her compound.

o   Pic 6: the builders started on the right side of the house, simpler because there is no neighbour issue there. I made sure they positioned the ridge level correctly, as well as the new roof level at the extreme end (Point E). Having those 2 points right, the roof pitch was determined and the builders could proceed without too much monitoring. Pic 6 shows how the column was extended upwards at Point E, on top of which a beam and a rafter could be positioned (I hope I’m using the right terms, I’m not a professional builder!).

o   Pic 7: progress by the end of the first day.

[sometimewoodworker]

23 minutes ago, gejohesch said:

One of the reasons to make a model on my laptop is that the left side of the house (point A) is very, very close to the wall that separates us from our immediate neighbour. I’m talking of cms here!

Just a point of information. The actual building regulations in Thailand require the house to be 2.5 metres from the boundary, this reduces to about 1 meter if there are no windows facing the boundary.
 

A temporary structure, like an outdoor kitchen or parking area, is permitted to have its own (again “temporary” in name) roof. So you will see many houses with different roof sections. Continuing the main roof over the “temporary” structure will not fly as it is then absolutely clear that it’s not temporary.

 

You may be OK if the OrBorTor never gets interested and the neighbours are all happy with you and always remain happy or your house is so far into the boonies that house plans are not required.

 

it is probable that it’s a “Topsy” house (it just grew) and that the difference in roof pitches is to skirt the regulations.

 

 

Edited March 15, 2022 by sometimewoodworker

[dddave]

On 2/4/2022 at 5:42 PM, itsari said:

Air flowing through the roof space is far superior to insulation in a tropical climate . That has been my experience 

Wasn't there an extensive discussion about the topic of attic/roof ventilation on this forum a few years ago?

AFAIR, a number of common misconceptions about handling airflow and the positioning of vents and fans were hashed over.   I recall that daytime heat build-up resulting in an overheated house at night was also discussed. 

I couldn't find it on search (big surprise!) but maybe somebody has it saved.

[gejohesch]

8 minutes ago, sometimewoodworker said:

Just a point of information. The actual building regulations in Thailand require the house to be 2.5 metres from the boundary, this reduces to about 1 meter if there are no windows facing the boundary.
 

A temporary structure, like an outdoor kitchen or parking area, is permitted to have its own (again “temporary” in name) roof. So you will see many houses with different roof sections. Continuing the main roof over the “temporary” structure will not fly as it is then absolutely clear that it’s not temporary.

 

You may be OK if the OrBorTor never gets interested and the neighbours are all happy with you and always remain happy or your house is so far into the boonies that house plans are not required.

 

it is probable that it’s a “Topsy” house (it just grew) and that the difference in roof pitches is to skirt the regulations.

 

 

Official regulations? In rural Thailand????

As you say, as long as neighbours do not raise an issue....

[gejohesch]

5 minutes ago, dddave said:

Wasn't there an extensive discussion about the topic of attic/roof ventilation on this forum a few years ago?

AFAIR, a number of common misconceptions about handling airflow and the positioning of vents and fans were hashed over.   I recall that daytime heat build-up resulting in an overheated house at night was also discussed. 

I couldn't find it on search (big surprise!) but maybe somebody has it saved.

I anticipate a bit on the reporting I have just started this morning: when all the new steel structure was put in place, and before putting the new metal sheets on top and closing the sides, we started laying the insulation batts on top of the drop ceiling. At that stage, the house was open at the top (no roof yet) but we immediately noticed a big change of temperature in the habitation beneath. Proof that the insulation batts were effective.

 

That of course is not to say that air circulation is not important.

 

It's not, I think, a matter of "do only this" or "only that works".

[sometimewoodworker]

33 minutes ago, gejohesch said:

Official regulations? In rural Thailand????

As you say, as long as neighbours do not raise an issue....

Thailand does have official regulations despite all appearances to the contrary. If they are enforced at the moment in your area is dependent on the local governments. It is often dependent on distance from a town or city.

 

That they are not getting enforced in any area is no guide to the future. 
That nobody is being pulled up on breaking the regulations is no guarantee that someone is never going to get proactive.

 

That, not only your neighbours, but everyone in the village doesn’t have a problem doesn’t mean that if you or anyone living in the house gets someone upset enough (something that’s the life and sole (pun intended) of villages) that they aren’t going to cause a problem for the house if they can.

Edited March 15, 2022 by sometimewoodworker

[gejohesch]

6 hours ago, sometimewoodworker said:

Thailand does have official regulations despite all appearances to the contrary. If they are enforced at the moment in your area is dependent on the local governments. It is often dependent on distance from a town or city.

 

That they are not getting enforced in any area is no guide to the future. 
That nobody is being pulled up on breaking the regulations is no guarantee that someone is never going to get proactive.

 

That, not only your neighbours, but everyone in the village doesn’t have a problem doesn’t mean that if you or anyone living in the house gets someone upset enough (something that’s the life and sole (pun intended) of villages) that they aren’t going to cause a problem for the house if they can.

You are right about how villagers can cause problems with each other. As a matter of fact, when I asked my wife why she had already built walls around her compound, before I knew her, she said that was because her 3 neighbours had caused her problems and had tried to push her around. They probably had seen her as weak when she inherited her parents' compound, and when she ended up alone after her firts husband's death on the road. Years later, she is still not on talking terms with 2 of the 3 families involved.

 

Now, if ever, the neighbour to whose wall our new roof is nearly reaching makes problems again, we will buy his house! He has already approached us a few times about it. Not too expensive and that would give us a lot of extra breathing space ????.

[KannikaP]

On 2/10/2022 at 3:10 PM, unheard said:

Whirlybirds do not provide any vacuuming effect - it's a prevalent misconception.

I'm not going to argue with your "evidence" here, just trying to warn others from spending money on a myth.

Totally agree. I had two x 22 inch professionally fitted, @ Bht 7000 each. Not noticed any difference even though there are soffit vents at many corners of my roof.

[Will B Good]

On 2/10/2022 at 3:10 PM, unheard said:

Whirlybirds do not provide any vacuuming effect - it's a prevalent misconception.

I'm not going to argue with your "evidence" here, just trying to warn others from spending money on a myth.

Is the spinning simply caused by warm air rising through the whirlybird?......If so the whirlybird will act to decrease the rate at which air vents out of the roof space.......if the spinning effect is caused by passing wind (not you personally)  then surely it would give some assistance to venting the roof space?

[gejohesch]

Not sure this really interests anyone anymore (I see recent messages on the whirly birds...., which I did not get into). But as I already have it ready, here is a recap of the works on Days 2 and 3.

 

 

Day 2: Continuing with the new steel structure (1)

By the end of Day 1, the first elements of the new steel structure had been placed on the right side of the house. Day 2 was all about continuing that work and moving on to the left side. As said before, the left side is more complicated because it nearly touches the (irregular) neighbour’s separation wall. That is shown on Pic 8. In the forefront, it shows a short vertical piece of steel 4” x 4” welded on top of the old structure. With the beam – rafter – batten combination that would come on top, that would bring the new roof to about 35 cm higher than the old roof, and ensure that the new roof pitch would be 12 degrees on that side also (as the ridge level had already been fixed in Day 1). Obviously, I made sure the builders would get that right (give or take 1 or 2 cms), as everything else would automatically follow from there on.

 

Pic 9 shows the progress made on the left side of the house by the end of Day 2. The last battens are being welded by the roof ridge. Note that the battens extend by several metres away from the house. That’s where we have an internal courtyard between our 2 houses, which serves as an external kitchen. The idea is to extend the new roof to cover that courtyard, where we often have problems with the heat and the rain. On the right of the pic, you see the terrace that covers the entrance of the house, and that connects to the second house (not shown here).

 

 

Day 3: Continuing with the new steel structure (2)

Not much to say in addition to the above. Just continuing with the same. A lot of work cutting steel, welding etc...

Edited March 16, 2022 by gejohesch
adding a line

[gejohesch]

Day 4: Hanging the dropped ceiling on the new structure; Starting to lay insulation batts

 

By the end of Day 3, the new roof steel structure was 100% in place. Pic 10 shows how crowded the top of the house had then become, with two sets of steel belonging to the old and new structures, respectively, plus a forest of wires attaching the dropped ceiling to the old structure. To be clear, the dropped ceiling is mounted on rails, which themselves are hung to the steel above.

 

We had all the dropped ceiling rewired up to the new steel structure, a matter of 2 or 3 hours only, which allowed to cut out most of the old steel out. This cleared the way (Pic 11), and we inherited a lot of steel, mostly 2” by 1”, that could be used somewhere else again. The insulation batts could be rolled out on top of the dropped ceiling – Pic 12. The rolls of 60 cm width fitted well enough in between the ceiling rails. Gaps were left out here and there, but nothing that I would consider as a major problem.

 

To give an idea of what a work site looks like in Thailand, Pic 13 shows the scene on the right side of the house (where we have our garage – to be renovated as well). We put a few old roofing sheets against the windows to protect them while welding steel above. I have never seen so far Thai workers (at leats in our part of the country) taking any special care of what’s around when they work. As a result, we’ve had a number of floor tiles and window panes badly damaged due to welding work in the past.