Cooling Systems For Roof

In this summer heat,when electricity is is off for 12 hrs ,and the sun heat boils the tanks waters on roof along with the roof itself, hot to the unbelievable level , and transmitting that heat down inside the rooms, where one cannot sleep or even sit,
My queries are 1= how can we insulate the roof ,so that its cool?
2= can we place some sheets at 3-4 feet height on roof or place some green house type mechanism,
3=or place some light weight plants check at some height suspension on roof ,
4= the idea of cool tiles or white cement will increase the weight on already heavy roof?
So what to do?
5=another mechanism can be thin [very low weight ]steel sheets suspended above roof to not allowing heat transmission down the roof?
Its a great puzzle. So please have your say and solution

Very important questions, answers of which will be very useful for all of us. Experts please do give your detailed views. Thanks.

I have some answers to it. But will post in parts. I just made my home and spent a lot on insulation. I did Jumbolon 2 inch foam. Than placing 3 inch concrete over it to protect and make its life long. I did everything by book.

Allhamdolillah heat transmission from lenter in absolutely zero. No exaggeration. Most welcome to cone and check it. I also did water tank insulation. It was not expensive. Just prior planning was needed. Unfortunately I couldn't find any solution to pipe insulation from water tank. All solutions were not long lasting. So hot water comes at start like normal homes, but than cold water starts.

Spent 4-5 lakh on total solution of insulation. At that time everyone said I am mad. But now its first season and proving its worth.

Now I will post some solutions to already built homes in next post.

By the way I also did proper double glazed windows towards sun side. But not much help honestly. Seem to be waste or extravagant spending of money. Only chicks can stop heat. Even curtains cannot stop heat as much as chicks do. Heat should be stopped at source. In heavy curtains, sun still enters our room and heat creeps in slowly. Heat from windowd should always br stopped from outside.

Continued.....

Now for built up homes.

UN-Habitat did research on insulation options and it's results. You can find on net. I read it many times. Discussed with a few experts.

Roof tiles is absolutely bad option. Just makes difference on 2-3 degree.

In my view, and its my own idea, that it would be great to build iron frame on roof. Have fiber on it. This way one can have more space in house.

Fiber reduces a lot of heat from entering the RCC slab. But it should be full roof because one part of exposed roof can make problem.

Whole concept hinges on the fact that Roof has iron bars in it. If one part heats up, it quickly transmits heat to other part of roof which is cold.

Even having green cloth on roof can make difference. But not much. Than, green cloth can tear/blow away in strong windstorms. All investment is wasted.

Having white paint type thing available in market named as roofflex etc on roof gives immediate relief. But it lasts for 2-3 months only. Further it becomes brittle and broken layer of that material goes into rain water drainage and chokes it.

Since stopping direct sun attacking roof can make some difference than why not have one time investment and make iron frame from lohaar and putting fibre on it. Fibre rolls are available in market like G-8 and city saddar road. One can enjoy rainy weather under it. No legal hiccup in almost having another storey.

In next post, would let you know a few options to reduce heat from interior of the house.

Nice information

Helpful Post.

What is the solution for houses which are already built.

I think there is some misconception here about double glazing. Double glazing works very well if done properly. You have to insulate the whole house and not just the windows facing the sun.

For built-up homes, if they can do such tedious thing, than remove the existing marble/tiles and mud from lenter, make it bare, put the jumbolon or Master EPS foam. Again some concrete on top of it and than fix marble or tiles on it. But all process is extremely difficult.

I think good option is to give shade to whole roof. Either fibre or green net cloth.

Insulated roof tiles are not very effective. Some companies sell tiles, enveloped with thermopore etc, but all these are not effective though these companies market it a lot.

Now if someone living in flat or some rented place where he/she can not invest on whole roof, he/she should try to insulate one room at least from inside.

Easy solution is ceiling. It also has limited efficacy but still cost effective.

Another good solution seems to be from an organization named Ghonsla. It was basically an NGO initially. They has project in Gilgit etc. They mix some local material like dry grass or hay. They do ceiling from inside. Interior wise they have good option for aesthetic purpose. The material is insulated and they probably seal it after installation.

I think this option would be good in the sense that it reduces a lot of heat. One room should atleast be insulated where kids has comfort at time of loadshedding when we cannot switch on AC.

Ghonsla can be searched on Internet.

Or you could use a room cooler. Its expenditure is almost equal to a normal ceiling fan. Its energy consumption will allow it to be used on a generator.

And you will see that you will have to turn it off in the last part of night because it would be very cold. :)

@ B.R Malik very nice info. Please tell about the rate of jumbolon.

B.R Malik Sahib, very useful information indeed. Thanks a lot.

@B.R MALIK

brother so kind of you

very nice contribution,i want to draw your attention to another observation,

AS i searched this foam jumbolon formula. And what i found was , that ,:if you place jumbolon [foam] on raw lenter,and then place 2 inch concrete on top of it,:the problem will be that the top most 2-3 inch lenter will not adhere perfectly on foam jumbolon, and as a result ,the top concrete will crack and allow water to dissipate down the jumbolon foam ,so more problems,

i don't have such an experience or observation , but just found this on net [ hope there are solution and better adhering formulas of jumbolon foam]

Thanks All for encouragement.

2 inch jumbolon board is Rs 85/sq ft. They give rate of Rs 100 initially followed by negotiations. 1 inch was Rs 42/sq ft.

Dk, you are absolutely right about that cracks. But one has to put thinnest iron bars in that concrete so that it holds together. I think it cost me around 30, 000/- for steel bars of 500 Yard roof. I have pictures when we did it. If anyone needs, I can email.

It was difficult for me to do whole process. No one understood exact procedure. Jumbolon people gave little information. But I did everything by book. Never paid heed to contractor advise or anyone else. I had to stand all the time in hear during installation and 3 inch concrete because everyone had strange attitude towards these things. No problem emerged till now. Even in last monsoon, 6 inches water remained for days on roof as rain water drains were not fixed yet. It was Eid and no one was available to drain the water. But no seepage issue. Till now zero problem

But Allhamdolillah, its really worth. Zero heat from lenter is something really great experience.

But unfortunately, double glazed windows towards sun side experience was not good. Finally I installed chicks in pindi facing windows and it had miraculous effect.

I opted not to do wall insulation. Walls are relatively cool. RCC slab absorbs a lot of heat and than transmit it back whole night. Than sun comes again.

Bricks are cooler and less thermal mass. Than we had houses on three sides. Jumbolon people were not technically very helpful. Than an important thing was that wall insulation means thick walls and your living area is reduced. Every inch is important in islamabad houses due to bye-laws restrictions on covered area.

Any more help, would be happy to answer.

Very detailed and helpful tips Malik sb !

And Dk thanks for bringing this question into discussion, it really unveils many things.

By the way, probably I missed one thing. People think that Mud is useful for insulation and it's waste of money in modern methods. Conventional wisdom is cheap. It's absolutely wrong.

Conventional wisdom cannot apply on modern houses. Of course mud is better than bare lenter but it has a lot of thermal mass. It absorbs heat slowly and release it even more slowly. More mud, more you will store energy in your roof to be transmitted later in the night.

Mud is cool only on mud I.e earth crust. Not on lenter.