INDESTRUCTABLEX:
Hello pro builders in the house. I will be starting my building project soon and I have been thinking about roof designs. Personally, I like the feel of flat roofs. But I had lived in a house that leaked heavily (just decking, no roofs). And this has given me reason to rethink.

The typical roof designs in Nigeria are pitched. Is this because of our weather? Is it more expensive or cheaper in the long run?

The idea for a flat roof is because I intend having a vegetable garden on the roof and of course DIY solar assemblies. Will this decision cost me more in the long run? And yes, I have limited funds

Good post! From a structural perspective both the flat roof and pitched roof are very do-able. It just depends on what you want. For the flat roof ensure that the roof is slightly slopy and make sure you add a tar coat on the roof to prevent inflow of water through the concrete and off course add room drains/pipes to expell runoff due to rain.

We used this method in constructing the control building in the substation.

Flat roof should be also more expensive but once done maintenance cost should be minimal compared to the pitched roof.

I hope this helps

mank1234:


What's building dimension? And what's the area of the roof?

26m x 14m.. Area of roof about 580 sqm

nextstep:


This is BRILLIANT!!!

Thank you sir

EfeEj:


Hello guys,

I love this discussion.

I stand for flat roofs over pitch any day any time. But i prefer to use a different technique to dodge concrete slabs in a flat roof as much as possible.

What I do is I make the roof parapet high enough that it can accommodate the slope of a flat aluminium roof in a way it Is still not visible from the outside. It depends on the design of the house and hence the roof design. So in most cases it comprises of;

A flat sloping roof to one or 2 directions covered with long span aluminium roofing sheet

Gutters that drains the runoff water from in-between the alu minium roof and the concrete parapet

Gutters should be treated with water sealants

Drain pipes to channel runoff water from the roof to the waste water system.

I guess with this it's a problem solved. No need to bother about the disadvantages of decking.

I hope this helps.

Regards,

Arc. Efe

i love the idea u just shared. i always love flat roof design because it is sexy and makes your building classy and unique from the uniformized pitched designs of nigeria homes. pls do u have any picture of what u just described now?

Flat roof is more than twice as expensive as pitched roof, apart from leakage concern which can easily be taken care of by tanking ( applying bituminous sealant/ felt) to prevent water from percolating, the issue of heat retention during the day and dispersion during the night , I.e it gets really hot at night.
That's is you get to spend more on cooling your apartment.

INDESTRUCTABLEX:


Kai. And I was so into growing vegetables on the roof. I am a space junkie, sorry.

You can also be a 'spliff junkie'...you can actually grow weeds on top of da roof. It won't smell in your house and the law enforcement wouldn't dare climb such height. They won't even know. The wind will disperse the 'aroma'.

Sniff dogs will be running round the neighbourhood trying to pin point the exact location.

Learning

KolaShangOne:


WE did something like that here on this project.

In fact you can collect water and pass it through drains in the pipes embedded in the columns as we did here.

After the deck, we applied felt (bitumen) on the parapet wall and controlled flow into the drain pipes..

Guy you just nailed it. You can used a concrete roof or hidden hip / flat roof. I done several buildings with such roofing method in the south. But instead of bitumen, I used sealant. And its working perfectly.

gbosaa:

You can also be a 'spliff junkie'....

You are not serious oooo

KolaShangOne:


WE did something like that here on this project.

In fact you can collect water and pass it through drains in the pipes embedded in the columns as we did here.

After the deck, we applied felt (bitumen) on the parapet wall and controlled flow into the drain pipes..

please is there a name to the particular bitumen you applied?

SwissGeneva:



Guy you just nailed it. You can used a concrete roof or hidden hip / flat roof. I done several buildings with such roofing method in the south. But instead of bitumen, I used sealant. And its working perfectly.

what kind of sealant? How and where did u apply it on the deck?

INDESTRUCTABLEX:
Hello pro builders in the house. I will be starting my building project soon and I have been thinking about roof designs. Personally, I like the feel of flat roofs. But I had lived in a house that leaked heavily (just decking, no roofs). And this has given me reason to rethink.

The typical roof designs in Nigeria are pitched. Is this because of our weather? Is it more expensive or cheaper in the long run?

The idea for a flat roof is because I intend having a vegetable garden on the roof and of course DIY solar assemblies. Will this decision cost me more in the long run? And yes, I have limited funds

These roofs are not necessarily concrete flats roof, you could make a low pitch roof by taking your wall higher, introducing gutters at at

least two points from you head course beams, Then you slant rafters to the gutters that will discharge to 6" pipes outward.


Questions to floodplain9@gmail.com

This is the design I made for my client and I'm also planning to construct it as well. Can someone help me with the name of the additive to be added during decking and the bitumen /sealant to use after. If possible where I can acquire then. Thanks for helping.
@KolaShangOne @ SwissGeneva

My own little contribution as a structural Engineer..

Any kind of design of roof by client should be made achievable.. Architect and Engineers should brain storm on how to archived the desire of the client..

Is only in Nigeria here that professionals like to do building construction the same way... Don't blame them, because that is what they are sure of...

There is what is called composite materials.. Engineers in the house will know this..
Example of composite materials is CFRP, carbon fiber reinforced polymer...

CFRP is what is been used now for our latest car body because of it high strength / weight ratio.. Our grand parent 504, 505 peugout Car are made of pure steel and alluminium.. That is why they are very heavy....CFRP is replacing steel which is known to be heavier compare to strength...

To cut the technical details, I will advice we professionals, Architect and Engineers to always think outside the box like other professional in the art do.. Even lawyers have started thinking out of the box this days collecting different restraining order..

Together.. Let us try and achieve clients idea..

Engr. A.L Onakomaya MNSE, RCoren..

micgray100:
My own little contribution as a structural Engineer..

Any kind of design of roof by client should be made achievable.. Architect and Engineers should brain storm on how to archived the desire of the client..

Is only in Nigeria here that professionals like to do building construction the same way... Don't blame them, because that is what they are sure of...

There is what is called composite materials.. Engineers in the house will know this..
Example of composite materials is CFRP, carbon fiber reinforced polymer...

CFRP is what is been used now for our latest car body because of it high strength / weight ratio.. CFRP is replacing steel which is known to be heavier compare to strength...

To cut the technical details, I will advice we professionals, Architect and Engineers to always think outside the box like other progression in the art do.. Even lawyers have started thinking out of the box this days collecting different restraining order..

Together.. Let us try and achieve clients idea..

Engr. A.L Onakomaya MNSE, RCoren..

I'm an Architect and because there's limit to what is available to us in the market, we are constrained. Now that you have shared the knowledge of this helpful materials, can you shed more light on it's usage in reference to the discussion at hand. If possible, where and how to get these materials.

CASTOSVILLA:
I'm an Architect and because there's limit to what is available to us in the market, we are constrained. Now that you have shared the knowledge of this helpful materials, can you shed more light on it's usage in reference to the discussion at hand. If possible, where and how to get these materials.

Thanks for your reply Architect.. As I believe we all are sharing knowledge here at no cost..
On the market constrained issue of CFRP.. Majority of composite materials including architectural and structural use are still ordered outside the country.. CFRP is no exception .. China, England, Germany and Italy produce CFRP with the specification you have provided.. As we have different grade of CFRP too.
It availability in Nigeria is restricted to magnitude of project for now e.g Shell Structures
One of my project using CFRP was a mobile hanger I constructed for a government Aviation Training School in Zaria.. Sent all my specifications.. And I received it in 30 working days from England..

The problem I see is the cost... Because is twice the price of normal steel.. But the training school know what they want and they were ready to pay the price.

Like I said in my previous comment, a client's desire should be worked out between Architect and Engineers and communicated to client without shying away from cost..

Yoruba adage says.. Soup wet sweet, Nam money Kill am..

Back to the topic on this trend ...my initial view on CFRP was just an example... But if I may come in on the issue of flat roof vs hipped roof..

The two is good depending on what the client desire..
Hipped roof is what is commonly used in Nigeria..
But if you want flat roof.. Will advice you do flat slab tilted with a little slope to run off rain water..the concrete must be very rich.. Grade 25.. Small screening can be allolowed to form another form of protection but is not a must..
Seallant like bitumen and epoxy sheets is always use.. The epoxy sheets are laid to cover the entire slab while the bitumen act as binder..

The problem I see here is that it needs constant maintenance.. And the maintenance involves changing the entire epoxy sheets within 4 to 6 years.. This is not economically good..

But engineers came up with what is known as shell structures to solve all these problems.. Many new generation churches and mosque in nigeria have embraced it... You can do a little research on google..

micgray100:


Thanks for your reply Architect.. As I believe we all are sharing knowledge here at no cost..
On the market constrained issue of CFRP.. Majority of composite materials including architectural and structural use are still ordered outside the country.. CFRP is no exception .. China, England, Germany and Italy produce CFRP with the specification you have provided.. As we have different grade of CFRP too.
It availability in Nigeria is restricted to magnitude of project for now e.g Shell Structures
One of my project using CFRP was a mobile hanger I constructed for a government Aviation Training School in Zaria.. Sent all my specifications.. And I received it in 30 working days from England..

The problem I see is the cost... Because is twice the price of normal steel.. But the training school know what they want and they were ready to pay the price.

Like I said in my previous comment, a client's desire should be worked out between Architect and Engineers and communicated to client without shying away from cost..

Yoruba adage says.. Soup wet sweet, Nam money Kill am..

Back to the topic on this trend ...my initial view on CFRP was just an example... But if I may come in on the issue of flat roof vs hipped roof..

The two is good depending on what the client desire..
Hipped roof is what is commonly used in Nigeria..
But if you want flat roof.. Will advice you do flat slab tilted with a little slope to run off rain water..the concrete must be very rich.. Grade 25.. Small screening can be allolowed to form another form of protection but is not a must..
Seallant like bitumen and epoxy sheets is always use.. The epoxy sheets are laid to cover the entire slab while the bitumen act as binder..

The problem I see here is that it needs constant maintenance.. And the maintenance involves changing the entire epoxy sheets within 4 to 6 years.. This is not economically good..

But engineers came up with what is known as shell structures to solve all these problems.. Many new generation churches and mosque in nigeria have embraced it... You can do a little research on google..

Thank you sir for your constructive reply. The use of shell roof is good development but many of my client have rejected the idea in many cases. Until someone decides to import these materials at least for some clients who doubt a lot (though they have the money) to see the usefulness of the CFRP you mentioned, alternative methods will always be the case.

In the long run if properly done will last. When I lived in North Africa and East our roofs were flat concrete. Parties on the roof and chilling out there.
In Delta State the building I'm staying has flat concrete roof but e dey absorb water like!! It's an old building and felting was used. Coal tar or recent but it's a mess. You can't get a competent person to resolve the problem. If you can't get it done right go for the roofing sheets. Almost every sick and Harry can do that. I'm already contemplating on doing that to give me peace of mind

INDESTRUCTABLEX:
Hello pro builders in the house. I will be starting my building project soon and I have been thinking about roof designs. Personally, I like the feel of flat roofs. But I had lived in a house that leaked heavily (just decking, no roofs). And this has given me reason to rethink.

The typical roof designs in Nigeria are pitched. Is this because of our weather? Is it more expensive or cheaper in the long run?

The idea for a flat roof is because I intend having a vegetable garden on the roof and of course DIY solar assemblies. Will this decision cost me more in the long run? And yes, I have limited funds

in Nigeria roofs with high pitch are encouraged due to our climatic system but terms of aesthetics flat roof looks better.
how would you water your roof garden and control the drainage from runoff water

Lules:
in

Sack or hydroponics

Thanks op for introducing this topic. I'm have a building plan with one flat roof and two shed roofs and hence this flat roof question has always been bothering me. Thanks for the exposition

Daud

Kola is very much on point with his terminology and technical summition
Slab is quite expensive compare to pitch roof
Please need a civil engineer That's good in structural design softwares to call me on 08029192813,09094538736
Oduntan.akeem@yahoo.com

I don't know much about building too but I have seen decked top of houses mostly found in high rise buildings which are covered with thick black materials that resist water - they look like leather but highly water resistance.

You will have to consider a tilt design of the deck so water can run down and not be retained. With this, you can be rest assured of a perfect design as you desire. #eucane_storm

INDESTRUCTABLEX:
Hello pro builders in the house. I will be starting my building project soon and I have been thinking about roof designs. Personally, I like the feel of flat roofs. But I had lived in a house that leaked heavily (just decking, no roofs). And this has given me reason to rethink.

The typical roof designs in Nigeria are pitched. Is this because of our weather? Is it more expensive or cheaper in the long run?

The idea for a flat roof is because I intend having a vegetable garden on the roof and of course DIY solar assemblies. Will this decision cost me more in the long run? And yes, I have limited funds

check my signature...

CASTOSVILLA:
please is there a name to the particular bitumen you applied?

no particular name sir

wetin I do you?

You can also be a 'spliff junkie'...you can actually grow weeds on top of da roof. It won't smell in your house and the law enforcement wouldn't dare climb such height. They won't even know. The wind will disperse the 'aroma'.

Sniff dogs will be running round the neighbourhood trying to pin point the exact location.

As a waterproofing expert I recommend you go for a decked roof bcoz the advantages it offers cannot be overemphasized when given the appropriate waterproofing solution to forestall seepage problem. Moreover it is cheaper cost wise when compared to roofing sheets

Virgindollars:
wetin I do you?

My company use APP (Actatic Polypropylene) membranes or SBS (Styrene Butadiene Styrene) membranes to protect the roof deck from seepage and leakage problems

You can call me on 08030537514 for more details on our waterproofing solutions

KolaShangOne:


no particular name sir

My company use APP (Actatic Polypropylene) membranes or SBS (Styrene Butadiene Styrene) membranes to protect the roof deck from seepage and leakage problems

You can call me on 08030537514 for more details on our waterproofing solutions

The roof is one of the main parts of the house. You can never save on this, as a good roof will serve you for a long time. If I were you, I'd take a nice sloping roof with tiles to keep the water out. I recently did roof repairs with the help of these guys www.roofcalgary.ca, as my roof was leaking. It's just a nightmare when it comes to eliminating messages.It is better to immediately make a good roof, so that you do not have problems with the fact that water enters the rooms, and can get on the wires, causing a short circuit and damaging the wooden parts.

I guess this picture is germane to this thread. A flat aluminum roof hiden by a raised parapet