Heat Insulation

Tin foil ? Maybe there is some body nearby who needs heat/energy (though I doubt it)and you can collaborate with a heat extraction scheme. I think you need to give more data - location /temperatures/budget etc.The more data , the better response you will get. Good luck.

Thank you.

I am living in a tropical country,India,where the temperatures can reach in Summer to around 45 degree centigrade.

I've always thought about this but don't know enough to say that it will be effective:

You might try putting soil on your roof and planting grass on it. That should serve as an insulation of sorts. This solution presents other problems, however, like:

• Keeping the soil on the roof. You have roof drains for sure and the soil will be washed out by rain.
• If you make the drains too small, the soil may clog it and you'll have flooding problems on your roof. Not good.
• You'll need to water the grass and that means additional water consumption.

Having grass on the roof seemed an attractive idea. I could put a recliner up there and relax a bit and maybe do my star gazing in comfort.

Your suggestion to 'Putting soil on roof and planting grass on it' can be the real solution. I am also fascinated with your idea to 'put a recliner up there and relax a bit and maybe do my star gazing in comfort'.

However,the following aspect needs clarification:

Due to watering the grass,the roof may remain permanently wet/damp.This may cause water seepage problem through the roof/walls. Perhaps my presumption may be wrong.Please advise on this also.

Due to watering the grass,the roof may remain permanently wet/damp.This may cause water seepage problem through the roof/walls.

You're right. That's an additional problem but not insurmountable. You could waterproof your roof. There must be several methods to do that mostly requiring a coating of some kind. Some of those can be sprayed on, painted with a brush or roller, or a sheet that you can lay down on the roof before putting the soil.

What do you think?

place 4-6 inch foam on the roof. Cover with pllywood and secure to the under roof with long screws on 8" centers. Then apply 1 layer of fiberboard and a rubber membrane roof. I did this on my flat roofed place and it cooled it by 20F on a hot day.

Being handy, I did it myself, it was easy, flat roof with a little slope. Contractors cost more.

The only other way is to do the same inside on the celing and cover it with plasterboard (gyproc) for fire approvals. It makes the room 6" lower, if you can tolerate that.

In germnany we have many experience with this kind of insulation.

And the results seem very good. The main advantage is: cooling in summer by convection and insulating in winter by the grass structure and the earth!

Years ago, I consulted with an architect whose passion was to build "earth sheltered" homes to ideally obtain a 180 day phase shift in extracting stored heat during the winter and storing heat in the mass of the structure during the summer. (Initially, I thought he was a kook, but I soon learned that he wasn't. I subsequently learned to not judge people frivously.)

I went to visit his home in South Carolina (he designed and built several in New Mexico) one 101 deg. F day in the summer to discuss electronic instrumentation so that he could quantify his efforts, and his home was very comfortable at 81 deg. F with low humidity (he only ran a dehumidifier -- no cooling).

The home was entirely concrete built in five bays with arched roofs. Each section had different thicknesses of earth ranging from 1 foot to 5 feet so that he could determine the point of diminishing returns on thickness of earth and structural strength needed for support.

Nonetheless, his home turned out to be quite energy efficient, but it was designed from the start to be earth-sheltered, and drainage was certainly taken into account, among other things.

One other suggestion: What's the feasibility of supporting and anchoring a light weight shading structure several inches above your existing roof so as to provide air movement (by convection if no wind) and protection from direct radiation? I suppose that sectional construction may be desirable for access to existing roof.

Good luck!

Use Tar sheets

Many of the replies are about the so called "Green-Roof" (grass over the top surface); this solution is effective but time consuming and sometime critical.

We suggest to look for "Cool Roof" coating.

It's very popular in the States (South area) and we import in Italy , you'll find a lot of Suppliers in USA

So it's not something new then? I've never seen a house with grass on the roof, not even on TV. I know of some houses or apartment buildings that have plants in pots on the roof and they use it like a park or picnic area but you're still stepping on concrete.

Anyway, that's how I plan to build my house...once I can afford to get one .

Australia's Parliament House in Canberra has grass on the roof. Several "eco" houses in Victoria also use this method. Sounds like trouble waiting to happen to me.

I once had to deal with a flat concrete roofed substation that got excessively hot, it was tar membrane sealed which made it worse. We got a local contractor called "Tempest Coat" to spray it with a polyurethane foam and skin system. It was the cheapest option and it worked (it stopped the water leakage too). The contractor arrived with a specially equiped 8 tonne truck and finished it quickly. Our other alternatives were to erect a gable roof and insulation or a tropical roof ( a steel sheet roof with an air gap between to ventilate any heat.

There is a special paint produced in Perth Western Australia (supposedly from Aboriginal technology). The name eludes me right now, but it is advertised in the newspapers, so try a search of Sunday Mail or the West Australian.

I've just dug up a back copy of the Sunday Mail. The product is called "Insulpaint" and is made by Cameleon Paints in WA. The Brisbane distributer's phone number is 38865684. They claim it is suitable for rainwater catchment and is good for your concrete. There are no web addresses in the ad, but I hope that helps.

One might simply cover the roof with a highly-reflective surface. Aluminium-painted roofs are not unknown.

One might fit a solar collector to the roof to provide a hot water service for the building, thereby also reducing the roof temperature.

One might fit a solar collector to the roof to generate electricity for storage and use locally, thereby also reducing the roof temperature.

In Singapore, inclined structures are added above the roofs of temporary structures so as to deflect rain and reflect heat; this provision is mandatory by local legislation.

One might investigate the possibility of insulating the underside of the roof so as to slow down the heat transferred to the interior.

Regarding adding soil over the top and other additions, beware adding significant weight to the roof before structural calculations have been completed and assessed, remembering to add in the weight of any water the soil may contain from time to time to the calculation.

I am delighted to observe CR4 forum could contribute so many suggestions / options within very small time. For convenience, these options are listed below:

1. Tin foil – Kris
2. Putting soil on your roof and planting grass, after waterproofing (by paint / laying sheet over roof) – Vulcan
3. Place 4-6 inch foam on the roof. Cover with plywood and secure to the under roof with long screws on 8" centers. Then apply 1 layer of fiberboard and a rubber membrane roof. Other way is to do the same inside on the ceiling and cover it with plasterboard (gyproc) for fire approvals. It makes the room 6" lower - ---Aurizon
4. Use Tar sheets ---- Guest
5. To look for "Cool Roof" coating. ----- MGEngineering
6. Tar membrane sealed which made it worse; spray it with a polyurethane foam and skin system. It was the cheapest option and it worked (it stopped the water leakage too); Other alternatives were to erect a gable roof and insulation or a tropical roof ( a steel sheet roof with an air gap between to ventilate any heat.; Use of special paint produced in Perth Western Australia; "Insulpaint" made by Cameleon Paints in WA ---- - Emjay4119
   

Next task is to shortlist and arrive at optimum solution.

All of the siggestions are good. Not knowing the intended use for your roof, my first suggestion is solar water heating, followed by reflective coating. But, many reflective coatings cannot within prolonged standing water.

There are several companies that manufacture sod-on-roof systems. They require the roof to be resloped for drainage, and roof drains to be installed. They usually consist of a 3 inch high supporting platform laid on the roof. Then a layer of geotextile is laid on the platform, then the sod. Of course, the roof and supporting should be analyzied to ensure that it can support the additional load and be stable in dynamic conditions.

Insulating is the most common for non-traffic roofs. And is relatively inexpensive, and easly to install. Your climate is similar to my area, and the membranes must be recoated about every 7 years here to prevent leaks.

With the green roof remember the weight it will add especialy in the wet. Collecting the suns energy is good but can be expensive, the reflective coating might work but could cause problems. The other way is to add an outer layer of timber and tiles so you have an air gap between the end are filled but have air bricks to allow for ventilation allow for a 12" to 15" gap between the two roofs. Just another random thought.

Paint the roof with the brightest white such as titanium dioxide white paint. We lived in the Mojave desert for 15 years where summer temperatures would often be in the triple digit range (F). Nearly everyone had a white roof, either with white paint,crushed oyster shells or gravel. A coating of white will reduce a roof temperatures by at least 15-20 deg.F.

I aerate ceramic cement (ambient cured) to 10 PCF (pounds per Cubic Foot)

This can withstand placing a 3,000 degree torch and not transfer enough heat through a 1" thick strata to be perceptable.

If you need info on how to do this let me know

Jonathan Hampton

tesla-was-right@hotmail.com

dear Mr Jonathan,

I was very inetrested in your idea of aeration of ceramic cement. Can u please elaborate on that. My email id is kohlis2005@yahoo.co.in

Regards

Kohli

Mr.Mani,

I responded to your email but it was returned. Do you have another email address. Or you can call me at 720-308-8906

Jonathan Hampton

^{Dear Mr Jonathan,}

^{Sorry to note your mail was returned.}

^{Can you please try to send the mail to my alternate e - mail address <nvmani34@hotmail.com>. Thanks.}

^N.V.Mani

I like the idea of a 'green' roof , though I wander what restrictions the local climate may impose . Another factor would be do you have a tropical storm season. A final thought is do you have a potential heat-dump such as a stream/river - is it a possible to collect low temperature water , pass it through a pipe array on the roof and return it to source . Even possibly just use water pumped up to the roof (into a large area shallow pan ) to evaporate heat . That may be a thermodynamic nonsense but every possible idea may help.

Regards , Kris

Mr.Mani ,during my previous visit to Kerala I have observed that many RC roofed houses having additional corrugated top roofing at height of eight to ten feet above the RCC roofing . I was told that this is to protect the house from water leakage caused due to heavy rains in Kerala. My visit there was in summer and one thing I observed was that this additional roofing gave a lot of cooling effect in the house .Probably this can solve your problem too. The white coating of the roofing is a good idea but if the there is exes rain in the locality you live this will not be advisable as you will have to paint it every time before summer.

INSULPAINT works unbelievably well. It reduced our sheds' temperature by 15 degrees cels. It is not ceramic rather made of plant fibre embedded in a styrene acylic base. It water-proofed small leaks also and the finish is beautiful like powder-coat. www.insulpaint.com.au

Very useful information.
Can you please give some information on cost aspect?
I am living in India.This product is not available in India,to my knowledge.
If the product has to be imported it may be very expensive.
It will be helpful to know whether any equivalent product is available.
Thank you.

You/they approach the problem of too much heat by insulation or preventing heat from coming inside your house. Why not cool it instead?

Use evaporative cooling. How? buy a sprinkler, install it on the roof, recirculate the water. Very common in Malaysia.