Waterproofing
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What is the remedy for leakages from RCC flat
roof?
It is
necessary to inspect the existing roof terrace and assess the reason for the
leakages.
Generally
the leakages may be on (a) account of the failure of the IPS of China Mosaic,
(b) the cracking and failure of the insulation layer, (c) the failure of both.
For
case (a) follow the steps below:
- Remove the finishing layer totally to expose the insulation layer. (Brick bat coba)
- Clean the insulation layer.
- Provide a 1:3 cement-sand levelling and smoothening course about 10 to 15 mm thick over it.
- After the layer in (iii) has hardened say 24 to 48 hours, on the wetted surface, apply Polyalk WP and cement slurry in the ratio of 1:1.5 (by weight).
- At 24 hours interval apply two more brush coats of the Polyalk WP Cement slurry.
- Cure with damp gunny bags.
- Finish as required.
In both case (b) and case (c)
follow the steps given below:
- Remove the finished & insulation layer to expose the structural reinforced concrete slab.
- Clean the slab and inspect for cracks and defects.
- Seal the cracks if any. First by applying a priming cum bonding coat of Polyalk EP Cement slurry in a proportion of 1:1 (by weight) to cracked concrete area (no water to be added).
- Level and smoothen the surface with 1:3 cement mortar about 10-15 mm thick.
- Moisten the RCC slab with water.
- Apply slurry of Polyalk WP and cement in the ratio of 1:1.5 (by weight) by brushing.
- At twenty four hours interval apply 2 more brush coats on the already applied coating.
- Allow setting for 48 hours.
- Cure the coating with wet squeezed gunny bags.
- Finish the surface as per requirement.
Please note that it is the
‘Polyalk WP’ – Cement Mix that provides the waterproofing.
