| Fri Jul 06, 2012 | Post #1 | sanjeev kumar
Join date: Jul 2012 |  Post subject: Hair line cracks in the ceiling on new 6 month o...
I can only see the crack in ceiling from below and do not know if it is on the floor of the roof as the roof is covered with polythene, wood and 1.5 inch thick bricks. Also, 10 mm rods were used across the lenght and width with 6'' spacing. | | |
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| Fri Jul 06, 2012 | Post #2 | ravi seth
Join date: Mar 2008 | Post subject: Hair line cracks in the ceiling
You must have put plastic conduits in the roof for electric wiring which must be going to the center where fan hook is.These cracks occur mostly at the bottom of the conduit when plastic conduit is not covered with wire mesh to improve its biding with concrete.Since these cracks are only limited to the bottom of plastic conduit it is not a worrisome issue but it does creates panic.Just next time when you repaint the house get these cracks filled with cement putty.
If you want to have a permanent solution , then get scratched the underside roof where the cracks appear till the bottom of that conduit say 2" -3" wide and depth till the bottom of conduit is., put a strip of chicken wire mesh and repair the same with cement putty and paint.Remember to use 1:6 cement : sand mix than a rich mix, otherwise you may get cracks again.... which then won't be due to plastic conduit but hair line cracks due to different expansion coefficient of a rich mix than used in the concrete above. | | |
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| Mon Jul 09, 2012 | Post #3 | S L Gupta (Civil Engg)
Join date: Mar 2008 | Dear Sanjeev
I agree with Sh Ravi seth that this crack is under the plastic pipe laid for electricity wires.The other cause may be that use excessive fine sand cause cracks in the RCC, it may due to not giving proper cover under cement concrete. As you stated the thickness of slab is 7'' than your RCC may be under reinforcemet etc. Please watch the crack for some time and if it not widened than it is OK and repair it as suggested by Sh Ravi Seth or visit the website gharexpert construction section here the article about cracks and their remedy is given. | | |
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| Fri Jul 20, 2012 | Post #4 | sam_m400
Join date: Jul 2012 | Sir
What is this wire mesh you are talking about? I have seen construction where electrical guy passes these conduits under the rods without any covering passing it to different rooms.
what precaution we should take asking the electrician while doing the conduit where barbenders are laying the rods across for the roof?
Regards
Sam
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| Sat Jul 21, 2012 | Post #5 | S L Gupta (Civil Engg)
Join date: Mar 2008 | Dear Sam
Do not place the conduits under the MS steel bars. First complete the bar binding and than on the bars lay conduit.In this process you have not cracks stated by sh Sanjeev and there is no fear of breakage in the pipe during laying of salb by walking of labor. | | |
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| Sat Jul 21, 2012 | Post #6 | sam_m400
Join date: Jul 2012 | Sir
In the mail he states "These cracks occur mostly at the
bottom of the conduit when plastic conduit is not covered with wire mesh
to improve its biding with concrete" . What does it means?
Your recommendation is that Do not place the conduits under the MS steel bars, so do we need to put conduit parallel to Stell bars or above it ?
do we need to tie the conduit along with the steel bars?
If it is above then there is chance that they will broken when somebody stamps while laying the concrete , but toeing along in parallel is good as it won't broken. which is best option?
Regards
Sam
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| Mon Jul 23, 2012 | Post #7 | S L Gupta (Civil Engg)
Join date: Mar 2008 | Dear Sam
If you put conduit under steel than the chances of breakage are more. lay conduit on the ms steel bars and tie them with steel bars. | | |
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