emmanilly:
You don't have a roof over the decked house and u re complaining of having a damped and leaky decking. Regardless of how many bags of cement used for the decking, it most retain some amount of water. Portland cement is super hydrophilic in nature so it must absorb water when expose to water. Try as much as possible to complete the building put a roof on the building. My two cents

wrong sir you don't roof it that's y it's called decking it's function is to carry that tank u see on it

Slawormir:
Damnnnnn niggarrr
Isoright
Let me learn

Be a real niggarrr
You are talking to a real niggarrr who is on the verge of roofing his building
Initially, I started it with the Idea of stone coated( metro tiles and parapet )
But when i realize the expenses halfway, coupled with the fact that i was spending money on steel rod i was left with no choice than to settle for a metcoppo or step tiles aluminium immediately it gets to roofing stage With 18ft wood work
still everything about the aluminium roofing and wood work according to my engineer is supposed to cost about 3million. To me the thing is still very expensive.
The only reason i will proceed now is the fact that i was told that those aluminium company gives discount when you patrionize them be it long span, step tiles and metcoppo. Atleast with that discount. A real niggarrr can have something remaining in his account to smoke some weed, bang enough Pussy and drink enough bottles

But you nor dey Benin city na. Na Benin city i dey.
Okay.. maybe next time. But I wonder if i go try this matter again next time because this building stress me. I nor know say to build house dey stressful and expensive o. I just dey see small small boys dey build house. Na im i say make me still start my own.

thanks my brother... nothing good comes easy. to me it worth the stress

tonididdy:


Yes it's quite reddish or pinkish and 1001% starchy clay... Everyone who has used the sand have rated it a 10 out of 10 not even a single stone can be found init

Ok bro.
I now understand

Hello bro,
First of all, I wish to console with you for the unexpected condition of the under- deck.
Secondly, I wish to comment that there is no amount of comments here that can give u the precise solution or cause of the defect. However, I will recommend that u look for a sound builder, Technically and academically trianed, to visit your site, so as to give u a precise diagnosis of your project.
It is often better when an experienced professional sees it himself.
My opinion.

tonididdy:


It's ok fam.
We are also looking at the possibility of excess heat because like I said before, the room is damped looking and the window glass sweat from the inside.

That's the building with two tankers untop... The water in this home is continually hot on a sunny day (the radiation and heat from the roof next to it keeps the water hot all day long, we are suspecting this to be the cause of the excess humidity level in the decked room.

What do you think?

Is the Area water logged?
Was there proper Damp Proof Membrane(DPM)?

danchuzzy:


The fact that most people who are not qualified professionals state something doesn't necessarily make it true mate.

Just like saying because you've owned a car, you now understand the intricate workings of the engines, cylinders and so on.

Except you give yourself to, and are really interested in the study of a particular subject, you'd basically be working with hearsay and not facts.

I can categorically tell you that the reference to what people have said so far lack facts. They've probably encountered a lot of "shady" builders who don't understand the workings of building materials and write off certain concepts they don't and cannot wrap their heads around.

There's nothing wrong, structurally or otherwise, with having a tank on a concrete slab sir, is what I'm trying to say, as far as the platform is properly built.

Cheers mate.

Everyone is entitled to their own opinion really, I guess this is yours. But people have stated a lot of sound reasons why it shouldn't be so. But of course you are quick to dismiss it because they aren't professionals and you want to flaunt your knowledge.

In my opinion its better to have a separate stand for the water tank. Instead of doing the way of the op, hoping your contractor isn't shady and actually knows what he is doing. Because in the end you will be the one to bear the extra cost if it isn't done properly.

This is Nigeria, so no I won't be so trusting especially if you personally don't know the exact structural requirements for something like this.

And I want to add this, just because someone isn't a professional at something doesn't mean whatever he says about something is untrue. Also your missing the point. No one is saying they will know the intricate stuff of every thing. The Bill Gates example I gave, did you hear me say he knows everything about infectious disease? Obviously not but experience and research has given hin enough information to give educated opinion.

Your third paragraph completely state what I am saying. Experience and research, need I say more? Now people armed with this can speak facts. But while speaking facts you need to understand where you are and how unscrupulous people are here. Its best to do something that will give you rest of mind. Thats the point.

Cheers

Are u not a nairalander?

obiekunie2:


if this ratio is acurate then the problem is from curing - it wasn't properly cured.

maybe you should try re-plastering those sections that are dripping.

sorry for my stupid reply - sometimes i behave like nairalanders.

jikins:


Everyone is entitled to their own opinion really, I guess this is yours. But people have stated a lot of sound reasons why it shouldn't be so. But of course you are quick to dismiss it because they aren't professionals and you want to flaunt your knowledge.

In my opinion its better to have a separate stand for the water tank. Instead of doing the way of the op, hoping your contractor isn't shady and actually knows what he is doing. Because in the end you will be the one to bear the extra cost if it isn't done properly.

This is Nigeria, so no I won't be so trusting especially if you personally don't know the exact structural requirements for something like this.

And I want to add this, just because someone isn't a professional at something doesn't mean whatever he says about something is untrue. Also your missing the point. No one is saying they will know the intricate stuff of every thing. The Bill Gates example I gave, did you hear me say he knows everything about infectious disease? Obviously not but experience and research has given hin enough information to give educated opinion.

Your third paragraph completely state what I am saying. Experience and research, need I say more? Now people armed with this can speak facts. But while speaking facts you need to understand where you are and how unscrupulous people are here. Its best to do something that will give you rest of mind. Thats the point.

Cheers

Oh well. I'm glad you see we agreed on something. .

Again, why I countered you is because you said just looking at the pictures, the water tank is not supposed to be there. And you asked me to go through the thread to get my reason for why and how you came to the conclusion. Again, those reasons are hearsay and there is no substantial evidence to support it. If you can show me research or evidence supporting your claim, then fine.


And citing Bill Gates doesn't hold water because he has spent a lot of time on research and collaborated including sponsored research on infectious disease.


Maybe if you say, based on research, that this isn't true, then I'd budge. FYI, there is a reason why concrete is specified for water retaining structures.



From my experience, People could be shady, it's better to do steel than concrete tanks stands et because of things like this... Okay no problem.


That water tank should not be there, merely looking at the picture. That's totally different.

Get my point, it's not enough to condemn something because you look at it and a lot of other people, I still posit, who don't have an experience on the subject matter, condemn the concept.

And for the record, I didn't say someone cannot give a factual opinion about something if he isn't a professional in that field. What I did say is, don't base those opinions on hearsay.

And to think I'm flaunting knowledge is also laughable. But your opinion not mine.

I hope you understand my point.
And no be fight baba.

Cheers again.

Are you waiting for it to collapse before you remove water tanks from the deck?
What are you coming on nairaland to look for? The deed has been done. Is it ordinary tank stand that you can't afford to build?
Remove those tanks and cover that particular deck with proper roofing.

dangoteinlaw:
my engineer I greet you, this is the only response worth reading coz you spoke using our terminology instead of those up there claiming to know too much. Problem with this our profession is that it’s been crowded with so many quacks that even the real engineers are now seen as irrelevant. Well I won’t state any solution, you see the whitish columns right there, well I pray the building collapses, one or two end up in the hospital and the artesian located and arrested then ppl will seek professionals to build even something as small as a store.

By looking at that slab soffit alone I am sure there’s been enough weeping to take away approximately half the strength of that binder but anyways it’s thier problem.

You have spoken well with bountiful sense.

If you have ever worked on a state or federal job, you won’t ignore the relevance of the machine even when your concrete is made workable.

sirlop:

When your concrete is made workable, you don’t need a poker vibrator. The problem should be either from curing or from the tanks at the roof top

Mayng01:
If you have ever worked on a state or federal job, you won’t ignore the relevance of the machine even when your concrete is made workable.

In such projects, you make use of panels for bracing. This guy obviously used a Carpentar to prepare his form work. Making use of a vibrator may scatter the form work. It’s best advised to make the concrete workable.

Yusful131:

What you are seeing is a result of do it yourself (DIY). next time try and consult a professional to handle your project to avoid lost of lives and property.
Solutions
1) try and vet the upper part of your suspended slab where you have your water tank. Your tiles might not be treated with waterproof materials like cilikagel and the likes. Concrete is permiable and can absord water at any time.
2) if the leaking continues, you have to remove the water tank from the slab and create a stantion for it.
3) never put any water tank in between your structure in your subsequent constructions.

You lots are so something else...

... Do you guys read at all?
I said this leakage isn't in the water tank area.... Anyway thanks for the advice.

frozen70:


Have you considered the weight of that tank, weather effects on it anytime it fulls and pour down

There is no way water will fill and off immediately without pouring or overflowing

I stand on my advice that its the effect of the over head tank that is affecting it

It will definitely continue like that until its removed

Talk about rainfall effects,

How often those the rain falls

Then how regularly does he pump water

Rain falls effects has no impact as the tank seating on a decking

It's never a good idea to mount a water tank on a concrete roof of a building

Ty

Hello OP,
From your post, I observed you used tiles to cover the decking. I'm assuming it's to prevent water seepage through the deck, #IMO that's not the best practice. The best practice would have been employing "Felt deck protection" to protect your decking. I do not advice clients to build roof decking in Nigeria because Nigerians (both Engineers & Artisans) do not have the technical know-how. So no matter how they build it, it'd rarely last for a decade before it turn leaky.

As for your building, during the construction, rather than employing the service of an engineer, you came to NL to get advice from every Tom Dick & Harry. I'm glad you can see the result for yourself (because you are about to spend twice if not more than).

My advice:
1. Create a proper roof gutter on your decking (if none is in existence)
2. Slope your decking towards the gutter (by adding materials(like mortar), I know it will increase the load)
3. Apply felt deck protection on the entire deck. pay special attention to the roof gutter and don't economise. Otherwise, you will have to fix your roof decking every raining season.

Ciao!

captainjay:

For your information I have 18yrs experience. I am a registered civil engineer. So I can't count. Do you have issues with your building?

Not at all

Can you please snap the pictures from the outside

dangoteinlaw:
my engineer I greet you, this is the only response worth reading coz you spoke using our terminology instead of those up there claiming to know too much. Problem with this our profession is that it’s been crowded with so many quacks that even the real engineers are now seen as irrelevant. Well I won’t state any solution, you see the whitish columns right there, well I pray the building collapses, one or two end up in the hospital and the artesian located and arrested then ppl will seek professionals to build even something as small as a store.

By looking at that slab soffit alone I am sure there’s been enough weeping to take away approximately half the strength of that binder but anyways it’s thier problem.

Respect bro. You see why we have so many quacks. People giving professional solutions online . How will Professional Engineers get jobs. I like how you ended it with all the possible consequences. I ain't giving any solution but my advice for him is to patronise Professional Engineers. End of Story!

captainjay:
Op. I am not sure you engage an engineer.this is a building that will last for 40-50yrs. Is the slab designed by structural engineer to carry the weight of the water tank? I can't see any beam under the slab which is wrong. don't let a mason who picked his experience on the road dictate technical things to you, seek the advice of qualified engineer .
The below list are What might have caused the dampness
1. The slope of the floor is not enough , this will cause water retention at the centre of the slab. Water will surely find it way through any concrete slab if the slope to the discharge pipe is not adequate.
2. The engineer should have advised you to lay polythene (water proof) which will cover the area of the slab before tiling the floor.
3. The engineer should have advised you to use water repellant chemical or cement mixed with ordinary Portland cement for wall plastering and floor tiles.
4. You can also cover the slab area with bituminous felt if you can bear the cost.
5. When you have done the 1-3 above ,pour enough water and put your discharge pipe to where the water gather at the wall.

And for the remaining part you don't have water tank make sure you cover it with roof, water will still find it way in the future.

Take care of what I listed above and thank me later.

So apt sir. But you just spilled a solution that ought to be paid for .
Nigerians will never learn...

hakeem4:


I’m sure you use C12/15 grade concrete. This is what you get for using low grade concrete

Yungmin micxwell

Hmm bro. I got your mention. The guy got recommendations on how to build from nairalanders .

tonididdy:

Oh no of cos am not angry.
I came here for responses and I don't mind in what manner it will come.
About the structure, it's about 14sqm and consumed exactly 14bags of cement... I can't remember the ratio exactly but it was a...


1: 3: 3 or 1: 3: 4 or 1: 2: 3 ( I remember I got the ratio on here on NL, accompanied with some good engineering sites)

The wall plastering may have being of poor quality but the under decking plastering was a ratio of 1 bag to 6 or 5 buckets.

Also untop the decking before the water tanks were placed is partially tiled.

Do you think we were still highly economical?

Modified: the water drops don't actually drop on the floor from the ceiling... They just hang there and I noticed that area is the lowest point in the under decking plastering.

It's also good to note this drops are not found anywhere close to underneath the water tank area. They are far away from where the tanks are. The decking underneath the tank area is 1001% completely dry always.

Chat me on WhatsApp for the solution.
08033702220 Engr. Frank

tonididdy:
Hi NLanders and Engineers.
Good evening.

This structure was built in December 2019.
I noticed the room is always moisty.
When the room windows and door is shut... The glass sweat from inside.

Now it's the roofing(decking), just this part of the decking.

The room is well ventilated but since no occupant the windows and doors are always shut.

Above the decking is completely tiled and two brand new water tanks are sitting untop.

What could this imply?

Zinc your house and it will stop.

tonididdy:
Hi NLanders and Engineers.
Good evening.

This structure was built in December 2019.
I noticed the room is always moisty.
When the room windows and door is shut... The glass sweat from inside.

Now it's the roofing(decking), just this part of the decking.

The room is well ventilated but since no occupant the windows and doors are always shut.

Above the decking is completely tiled and two brand new water tanks are sitting untop.

What could this imply?

I am just seeing this. I hope u have gotten the correct solution preferred to you in one of the many pages of this thread. If not, consider these carefully.
1. Ur slab(decking) fabric is heavily saturated with water sipping into it steadily in small amounts.
2. The colour of the water droplets is brown because it has some ferrous content due to stains by your reinforcement.
3. I can see ur riser and main supply pipes are surface-laid. Definitely the problem is not from there.
4. The most likely culprit is ur overflow discharge pipe. Check the floor drain. For all my kobo, that's where the problem is.
5. Check around the edges of the floor drain for possible sipping holes. You might need to grout the edges properly with pure cement paste.
6. If No5 above doesn't apply, tell ur plumber break open the floor drain and replace it. Its likely that he didn't use enough gum to hold the floor drain and the overflow pipe together.. Peace be unto you IJN

As a waterproof engineer.

An exposed roof slab is supposed to be waterproof.

Even the best construction companies in Nigeria waterproof their exposed roof slabs and other wet areas, like terraces and toilets.

All you need to do is create some floor drains, channel the pipe down.

Apply a waterproofing membrane coats.

Do a rich screed on it preferably (1:3 I.e 1 bag of cement to 6headpans of sand )

,don’t use Buckets this time around use an head pan .

Make sure your screeding is sharp slope to the floor drains

Your dampness issue is solved.

poor construction, that deck needed a DPM

hakeem4:


I’m sure you use C12/15 grade concrete. This is what you get for using low grade concrete

Yungmin micxwell

I do not think the problem is about the concrete grade. Infact, it's definitely not the concrete grade. This mainly a ventilation issue that revolves around thermodynamics. He should try to insulate the building to some extent. Painting it and perhaps pop on the slab would work. Install air extractors if possible. What kind of blocks were used? If it solid blocks, it could be a cause as well. But it is definitely not the class of concrete used.

troubleshooter:

I am just seeing this. I hope u have gotten the correct solution preferred to you in one of the many pages of this thread. If not, consider these carefully.
1. Ur slab(decking) fabric is heavily saturated with water sipping into it steadily in small amounts.
2. The colour of the water droplets is brown because it has some ferrous content due to stains by your reinforcement.
3. I can see ur riser and main supply pipes are surface-laid. Definitely the problem is not from there.
4. The most likely culprit is ur overflow discharge pipe. Check the floor drain. For all my kobo, that's where the problem is.
5. Check around the edges of the floor drain for possible sipping holes. You might need to grout the edges properly with pure cement paste.
6. If No5 above doesn't apply, tell ur plumber break open the floor drain and replace it. Its likely that he didn't use enough gum to hold the floor drain and the overflow pipe together.. Peace be unto you IJN

Ok sir thanks will keep you posted.
The water drops btw aren't brown... Crystal clear colour just like normal water.
Once again thanks

yungmin:


I do not think the problem is about the concrete grade. Infact, it's definitely not the concrete grade. This mainly a ventilation issue that revolves around thermodynamics. He should try to insulate the building to some extent. Painting it and perhaps pop on the slab would work. Install air extractors if possible. What kind of blocks were used? If it solid blocks, it could be a cause as well. But it is definitely not the class of concrete used.

Yes 9inch solid blocks not hollow.

iamademola:
As a waterproof engineer.

An exposed roof slab is supposed to be waterproof.

Even the best construction companies in Nigeria waterproof their exposed roof slabs and other wet areas, like terraces and toilets.

All you need to do is create some floor drains, channel the pipe down.

Apply a waterproofing membrane coats.

Do a rich screed on it preferably (1:3 I.e 1 bag of cement to 6headpans of sand )

,don’t use Buckets this time around use an head pan .

Make sure your screeding is sharp slope to the floor drains

Your dampness issue is solved.

Will surely be done.
Do you advice I mix water sealants with the cement mixture?

tonididdy:

Yes 9inch solid blocks not hollow.

Lol, there you have you problem

Why would you use solid blocks for such? You don't know the holes in a hollow blocks serve a purpose? The best you can do now is to install air extractors or provide some insulation for the building interior