Flat roof waterproofing materials??

[Tapster]

I've searched the forum but I can't find any references.

 

I have a leaky flat roof.

 

What can I buy to waterproof it, and where can I buy it?

 

Ideally, I want a simple paint-on coating, but I'm happy with any advice.

 

Thanks for all comments.   ????

[uwe_rayong]

I had success with SIKA Roofseal, 20kg about 3000.- THB.
Do you already know where the leak is? Water runs everywhere. Can be very tricky, especially if you have a leak only when it rains very hard or for a lengthy time. I had that problem.
It was a tiny crack in a wall  near the ceiling. The water came through the ceiling in the middle of the room, 3 metres from the wall. The water was running in the Aluminium construction for the ceiling.
Took me a couple of month to find the tiny crack in the wall, I painted the flat roof three times ????????????. before I found the crack in the wall.

 

 

 

 

Edited November 11, 2018 by uwe_rayong

[Tapster]

@uwe_rayong

 

Great, thank you.

 

I suppose I can get that at HomePro, can I?

 

Did you apply it with a roller or a brush?

 

The roof is very small, approx 2m square. If I can't find the leak, I'll just do the whole roof. In fact, I'll probably do the whole roof anyway.

 

You did just one coat? Is that what they recommend?

 

Cheers   ????

 

 

[eyecatcher]

There are several brands that all seem to do the same products re water seals. Looking for what you think you need will take you an hour just to compare the 6 companies doing the same.

most of them are geared to be brushed on or troweled on but I have tries both ways and troweling is easier from a tub and you feel a better thickness has been applied, brushing on always ruins the brush and difficult to guage what you have applied.

More often than not, it will recommend 2 coats as a minimum so bear that in mind when you look at the coverage on the tub.

 

 

if you are certain where the leak is, and feel theres no point doing a full area then you can buy the sika plugs, a cement putty applied directly into the crack. Dam walls easy!!

 

for 2mx2m there is no need to go for the 20kg bags of sika as you will only use a third of it, probably better to get a couple of 4kg tubs (and latex) for about 400bt each (Besbond for example)...remember when its mixed it is applied at a few millies thick that's all.

 

[Tapster]

@eyecatcher

 

Thank you very much.

 

What's the latex you mentioned?

 

????

[eyecatcher]

2 minutes ago, Tapster said:

@eyecatcher

 

Thank you very much.

 

What's the latex you mentioned?

 

????

Most of the waterproofing products come as two components, the powder (which is to my mind simply weber floor tile adhesive re branded) and a bag of latex waterproofing "milk"

 

if you buy buy the 20kg sika bags, you get a 5 litre (I think) tub of latex to mix in.

with the 4kg tubs the latex is in a plastic bag inside the tub, and you mix the whole lot in the tub itself...straightforward really. 

 

my reference to weber floor adhesive before, came about when I bought some of this. the powder was identical, and the same colour and it smelled the same. Add the latex and you have a waterproof floor adhesive for bathrooms and ….don't forget they hike up the price to make it special. its not!

 

give it a go, for me n future I will buy a regular 7kg bag of 200bt weber and add the latex into it,...worth experimenting sometimes.

[Tapster]

Thanks for the explanation. 

 

Last question: don't they have any good old petroleum-based black gloop as might be used in temperature climates? Maybe that would never set in the tropics. 

[uwe_rayong]

4 hours ago, Tapster said:

@uwe_rayong

 

Great, thank you.

 

I suppose I can get that at HomePro, can I?

 

Did you apply it with a roller or a brush?

 

The roof is very small, approx 2m square. If I can't find the leak, I'll just do the whole roof. In fact, I'll probably do the whole roof anyway.

 

You did just one coat? Is that what they recommend?

 

Cheers   ????

 

 

All the major hardware stores have several of these products. I bought it at a"Harwarehouse".
Sika Roofseal is already mixed. Consistency is like a thick paint. 2-3 layers are recommended. First coat diluted. For just 2sqm one or two 4kg buckets should be sufficient. 
They have a like 2-3 colours of that stuff. It is easy to apply.

 

 

 

[rawhod]

For a simple paint on coating we had good results with TOA 201 Roofseal on our kitchen extension roof.