Cooling The Roof Down

[CS Chua]

I read form other thread you have sensitive nose problem..!!

Beware of rock wool, check how the rock wool is installed

The tiny fibre from the rock wool certainly won’t do much good to sensitive nose..

My opnion is :
No need to re-invent the wheel, if you don't spend long hous there, just install an air-cond and pay extra for electricity (maybe the incremental is just 30-40 ringgit a month).

You got a point there about my nose! Completely forgotten about that. Maybe I should stick to my trusty air con by switching it on one hour earlier before I sleep. As for the kitchen I am going to find a big ventilation fan!! The one the fried koey teow uses.

[fRaNkY]

add a layer of attap roof, there r many coconut tree around subang

[Minuteman]

I have had some bad experience with "rock wool". I bought and renovated my house in 2000. Rock wool was installed on the underneath of the roof. About 4-5 years later, I had a small leakage and decided to get my contractor to repair it. When he opened up the roof, I was shock to see that many parts of the rock wool has turned from yellow colour to greenish black. Aparently the dampness from the leakage as well as the humid air in M'sia cause the mold and fungus to growth. In the end, I had to spend more money to remove it (some part of the wooden beam was affected as well). It is also true that hot air gets trapped underneath and cannot ventilate out (unless you have a turbine ventilator installed). Rock wool is quite hazardous to handle as in overseas I see workers doning breathing apparatus and full body suit when installing and removing. I found small dust/ needles all over my ceiling board after they have removed it. Had to spend some time vacuming all of it.

All methods mentioned has their pros and cons. Using sprinkler is good but a waste of water and can cause molding/ fungus growth in the surrounding due to dampness. It is not so environmentally friendly as well. This is the same with using electrical sunction fan. When I was in Australia recently I saw many of their milk/ dairy silos painted white. I was told by them that they painted it with a "hollow ceramic" paint, a type of paint used by Nasa for their space shuttle. Apparently it is very effective to keep the heat away. I don't know if it the same mention earlier in this same thread but it is probably the more environmentally way of doing it.

[currymee]

Bro,

Before you said best way… you know I always have the best way

Stay in a condo , no roof ---->no roof heat problem at all …

Hahahaha Ok, I concede on this logic of argument True, no roof, no problem !!

Looking at CS Chua "problem", it is basically (IMHO) about getting sufficient VENTILATION and AIR-CIRCULATION to remove the trapped heat (forced convection since the cycle of natural convection is blocked by the 4-walls and roof) - let's face it, we are living in Malaysia, inside ANY BUILDING, there will be trapped heat !!

I remember that the "old houses" (including the one I was raised up as a child) were build with wire mesh "netting at the top" or perforated brickworks near the ceiling, and with the aid of the ceiling fan, this is to allow the natural convection and escape of heat - see our "ancestors" got it right all along

Fast forward to today, because everyone is scared of crooks climbing in through these "air-ducts", we brick up all the way to the roof - I like the idea of "perforated bricks" in my future renovation and to avoid mosquitoes, just put a layer of aluminium mosquito nets - the ONLY HAZARD, I have not figure out how to prevent coming in is the Indonesian SMOG !! - maybe add a small window, so 3-layers -
1) perforated bricks (allow air movement but prevent crooks)
2) mozzie nets
3) windows (like the bathroom ones) to keep out the Indonesian smog !!

And I THINK the estimated cost should be LESS THAN RM2K (within CS Chua budget) - BUT DON'T QUOTE ME !! - environmentally friendly and no additional cost whatsoever in terms of electricity of choking on rock wool.

[Henry T]

Google CSR CoolBatts.

The Rockwool is wrapped in insulation foil. I did it recently. Makes a big difference. Was told 70% of the heats comes through the roof, 30% through the wall.

In your case they will have to lift up the tiles on the outside to insert the Rockwool blankets. If there is a ceiling they will just place them on top of it.

:-)

[LMei]

I read that the best and simplest way is to paint your roof white. Question is, do you want a white roof?

[Henry T]

I read that the best and simplest way is to paint your roof white. Question is, do you want a white roof?

Not good enough. What we need is insulation. Polyurethane, Rockwool or Fibreglass. The higher the density the better. Polyurethane can add to any fire, Fibreglass is going out of fashion. So that leaves Rockwool.

Our mass produced houses are bare-bones. Underneath the concrete roof tiles is just a thin aluminium + paper foil and nothing else. Then you have a thin layer of plasterboard as the ceiling.

In a tropical country like ours, our houses can be better designed. But why do they care when even poorly designed houses sell like hot cakes. By this I mean functionality and not aesthetics.

We spend a lot on electricity just to cool the house down.

Another good product for our hot climate is ALC blocks (Autoclave Lightweight Concrete). Use it for the walls, replacing the conventional clay or cement bricks when you renovate your house. You can Google it.

[DarkNite]

Another good product for our hot climate is ALC blocks (Autoclave Lightweight Concrete). Use it for the walls, replacing the conventional clay or cement bricks when you renovate your house. You can Google it.

Use for building Tesco.

[kwchang]

... for the kitchen I am going to find a big ventilation fan..

I don't think you need a hurricane fan. Just get yr contractor to make a small hole at the highest point in the kitchen wall and install an extractor fan. But be aware you don't cut any hidden power cables or security system wires as wiremen like to run wires at the highest parts of the wall. Simple physics - hot air rises, so you put an extractor fan at the highest part of your kitchen and suck out the hot air.

[USJ27Resident]

I don't think you need a hurricane fan. Just get yr contractor to make a small hole at the highest point in the kitchen wall and install an extractor fan. But be aware you don't cut any hidden power cables or security system wires as wiremen like to run wires at the highest parts of the wall. Simple physics - hot air rises, so you put an extractor fan at the highest part of your kitchen and suck out the hot air.

Told you so, in my PM.... I put that extractor on the ceiling itself... which sucked any of the hot air out of the kitchen into the low roof... which also kinda raised the 'pressure' in the roof and help push the hot air out of the roof thru the roof tile gaps...

Worked wonders... till we added a floor over the kitchen...

but if you have a concrete slab as your ceiling... then your alternative is to put a turbine (under RM350 I think ) on the roof lorrr...

[CS Chua]

I don't think you need a hurricane fan. Just get yr contractor to make a small hole at the highest point in the kitchen wall and install an extractor fan. But be aware you don't cut any hidden power cables or security system wires as wiremen like to run wires at the highest parts of the wall. Simple physics - hot air rises, so you put an extractor fan at the highest part of your kitchen and suck out the hot air.

What is an extractor fan? If I put a fan pointing upwards, wouldn't the rain water go into my roof? Are you referring to those turbine thingy? Oh, you mean hole in the wall. Well, I have one already for the cooker. However, it will also draw in the afternoon heat. It is the heat between the roof and ceiling that needs to be taken care of.

[kwchang]

What is an extractor fan? If I put a fan pointing upwards, wouldn't the rain water go into my roof? Are you referring to those turbine thingy?

The thing on the roof is USJ27resident's idea - I think he meant a fan blowing into the attic space above the ceiling but yr kitchen ceiling is flush with the roof tiles, so it is not the solution.

No, I am not suggesting a turbine installation. The extractor fan is placed on the wall (u need to have a hole made on the wall first). This fan blows outwards (hence extract). Some houses install this in their kitchens to redirect the cooking fumes outside when they do not have a cooker hood.

[Naka]

I think the water sprinker system is easy but maybe expensive in the long run.

[bslee]

I think the water sprinker system is easy but maybe expensive in the long run.

Water sprinkling isn't good when applied to roof tiles that are mostly common cheap cement roof tiles. Water will cause the tiles to disintegrate, deteriorate or breakup in due course. Not only that, fungus and mould will also form and make it look unsightly. The power of water, what more should I say.
Actually there must be some form of heat insulation installed during the building of homes, but due to obvious reasons, its almost never unless one design and build own home with cost no object. Its all a compromise for cost, value and effectiveness when doing this kind of thing after the home is already built. Cost?..definitely always a primary reason towards whatever is decided on. I recall when my dad built our family home in the mid 60's, the roof was lined with rockwool insulation, no wonder the home was very cool all the time. I knew of this much later on when I used to climb into the roof to do maintenance works and had to access it by opening some roof tiles. My brother who lived there later on, later replaced all the roof tiles to terracotta tiles after 30years, and the house became even cooler then.
Comparing my home to a neighbor's house which is virtually standard from build, its HOT AS HELL upstairs compared to mine, with entirely UNECCESSARY WASTE OF PRECIOUS energy to switch on airconditioning just to ensure upstairs rooms are cool and comfortable. All the money wasted on energy all the years could easily have paid for new roof tiles and heat insulation measures. Penny wise, pound foolish.
BTW, Rockwool insulation with so called "bad effects" and ROOF LEAKING is TWO different issues. You don't mingle them together. First YOU ENSURE your roof system is near perfect without any leakages and all tiles are intact for all purpose and intent. For a fact EVERYTHING in a home need some form of inspection or maintenance and so is one's ROOF tiles. Don't wait for it to leak, then do something. It was from one own particular inspection that I detected a leaky mains water pipe to the water tank and rectified it immediately before dripping water will make holes in my upstairs plaster ceiling. The ori as**** contractor who installed the piping didn't do a perfect job, it leaked at the pipe joints. I inspect my roof area every 6 months or so for any visual defects including water system.
If I have the money now, you bet I'll replace all my roof tiles to terracotta tiles without flinching. Make own home even better for my lifetime.

[Naka]

Water sprinkling isn't good when applied to roof tiles that are mostly common cheap cement roof tiles. Water will cause the tiles to disintegrate, deteriorate or breakup in due course. Not only that, fungus and mould will also form and make it look unsightly. The power of water, what more should I say.
Actually there must be some form of heat insulation installed during the building of homes, but due to obvious reasons, its almost never unless one design and build own home with cost no object. Its all a compromise for cost, value and effectiveness when doing this kind of thing after the home is already built. Cost?..definitely always a primary reason towards whatever is decided on. I recall when my dad built our family home in the mid 60's, the roof was lined with rockwool insulation, no wonder the home was very cool all the time. I knew of this much later on when I used to climb into the roof to do maintenance works and had to access it by opening some roof tiles. My brother who lived there later on, later replaced all the roof tiles to terracotta tiles after 30years, and the house became even cooler then.
Comparing my home to a neighbor's house which is virtually standard from build, its HOT AS HELL upstairs compared to mine, with entirely UNECCESSARY WASTE OF PRECIOUS energy to switch on airconditioning just to ensure upstairs rooms are cool and comfortable. All the money wasted on energy all the years could easily have paid for new roof tiles and heat insulation measures. Penny wise, pound foolish.
BTW, Rockwool insulation with so called "bad effects" and ROOF LEAKING is TWO different issues. You don't mingle them together. First YOU ENSURE your roof system is near perfect without any leakages and all tiles are intact for all purpose and intent. For a fact EVERYTHING in a home need some form of inspection or maintenance and so is one's ROOF tiles. Don't wait for it to leak, then do something. It was from one own particular inspection that I detected a leaky mains water pipe to the water tank and rectified it immediately before dripping water will make holes in my upstairs plaster ceiling. The ori as**** contractor who installed the piping didn't do a perfect job, it leaked at the pipe joints. I inspect my roof area every 6 months or so for any visual defects including water system.
If I have the money now, you bet I'll replace all my roof tiles to terracotta tiles without flinching. Make own home even better for my lifetime.

I see, so it's 'cheap cement roof tiles'