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How to join old and new concrete roof slab

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  5. How to join old and new concrete roof slab
Asked: 2019-11-17 05:51:57
Some solid advice required here please, I have to join flush a new rcc roof with the existing rcc roof that rests on a load bearing brick wall. The new roof slab is supported by columns on the other side. Help?


Answered: 2019-11-17 16:55:00

You can put a stopper on both sides of the joint. One stopper should have a canopy at the top and extend over the other stopper. Treat this with good waterproofing coating. Then, if you don't want dripping, put a drain (half cut pipe) under the joint and give a slope joining it into a down drain. Good luck.


Answered: 2019-11-19 03:13:51

Newly laid RCC slab can be jointed with the existing slab if you put in a suitable construction joint. How to do this? Taper the edge of the slab 45 degrees backwards. Ensure that the bottom shuttering is perfectly in level with soffit of the previous slab and is well plugged to prevent leakage of grout. Clean the taper edge with water and apply thick cement grout scrupulously and cast the new slab.


Answered: 2019-11-18 00:59:43

New RCC slab can be joined with the existing one. Follow these steps:Chip off the existing slab up to a certain depth (preferably around 15 cm) Drill reinforcement bars into the existing slab Apply a bonding agent so as to act as a bonding agent for new and old concrete. With the support of formwork cast the new slab.


Answered: 2019-11-18 06:04:54

People will say it can't be done, but they are wrong! I found this video pretty good, hope it helps you. description


Answered: 2019-11-18 01:54:26

It's kind of hard to attach old concrete to new. I'd get it inspected before you go tinkering with it. Concrete is no joke and if you have too much weight you could collapse the roof. I know cos it happened to my brother. So, you might have to do the whole roof.

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