Based on what been told to me by the applicator(sorry if its not correct) it can last 10-15yrs...we are talking about the same material that has been used on big project, bridge, tunnel etc

The question is still whether it can take all the expansion and contraction(thermal movement) due to weather.

Here's something I found:



Source: http://www.waterworld.com/index/display/ar...filtration.html

This post has been edited by tehtmc: Feb 18 2012, 01:49 PM

just use this method to settle the swimming pool leaking problem



solve/ stop the water with grouting first lar, it may come back later but u have no choice now...

That's true, it's not as if you have other choices though it may not be 100%.

How much does it cost?

the cost depend on how many packers/point u need to use, i think the rate now around rm80-150 per point.. , u can ask them to put less first, then see if it still leak or not

my 2 posen

This post has been edited by sn4: Feb 18 2012, 01:52 PM

Why don't you try to put metal roof right on top of the slab with a little bit inclination for water to flow down. Maybe it will work if no water come in contact directly with the slab.

The keyword here is "no water should touch my flat concrete roof" .

Yes, this is the best solution and it is permanent. Have to spend more though.

my house flat concrete roof leak after 4 months.i will try to ask the contractor to use the pu grouting.just hope it can be solve once and for all.concrete roof is sure a pain in the s

dig up 1 - 2 inch concrete, reapply proofing. Else sun may just kill it on surface

If it is for bathroom I'm sure it will work as I have tried. For outdoor, I don't think it is 100%.

most of the flat roof leakage at house extension will occur at the cold joint with the existing structure, due to minor settlement of the new structure built by the reno contractor, without proper footing/ foundation...

mine is for the newly built extension room

mine don have proper footing as he said bakau cant enter the earth.so it is ok not to use footing

Can't imagine a room having a concrete slab over a room. Contractor's suggestion?
Isn't it hot?

This post has been edited by tehtmc: Feb 21 2012, 11:04 AM

yup.quite hot.he say is is cheaper than renovate the whole roof for the house.just use concrete slab instead is cheaper.now the cause of the leaking maybe is becoz of the slight crack on the wall due the earth movement?or maybe due to his skill in foundation


if i ask him to reapply sealer and water proof inside wall and recement it.then use pu grouting.is this the best idea?

If that is the case, my advice is to have metaldeck roofing over - the factory-type roof.
The slab is not wasted as it provides the support for the metal roof.
You need to have insulation for the metaldeck to overcome the noise problem or it would be noisy when it rains.
You not only solve your waterproofing problem, your room would be cooler and more livable.

so now the top layer is
metal deck --> insulation --> concrete slab?

what should i do to have the insulation?

You need to have a few steel C purlins on the slab to receive the roofing and lay it with a gradient(few degrees)

steel purlins (4"x2" abt 5 ft spacing) ---> a layer of chicken wire netting---> rockwool insulation ---> 0.48mm metaldeck Zincalume roofing

I don't know how your flat roof joins the existing roof. Any picture?

Get a roofing contractor to give you a quote. Probably a 1-day job.

This post has been edited by tehtmc: Feb 21 2012, 11:35 AM

sorry,no pic of it.i din went to have a look b4.will have a look at it this sat as the contractor coming to see the problem.

and thanx for the advice.i hope it could take care of it once and for all

---

Added on February 21, 2012, 10:43 pmdo u have any roofing contractor number for penang?

This post has been edited by noien: Feb 21 2012, 10:43 PM

and here is the pic of the existing roof and new concrete slab


Attached thumbnail(s)

The 2-3" clearance between the old roof and slab is not enough to have the new metal roofing underneath.
You need to modify the end of the existing roof to do a valley gutter. /\/\
What is the depth of the extension?

No, I don't have contact in Penang.

P.S.
Another way to do it, the simplest way:

Forget about purlins and insulation. Lay the metaldeck roofing sheet directly on top of slab, tilt it to fall to back as much as you can (2"-3").
The edge of the roofing sheet below the existing roof eave should be turned up ___]
Roofing sheet to project 1 ft beyond the edge of slab on all three sides.

This post has been edited by tehtmc: Feb 22 2012, 12:20 PM