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Sub floor ventilation to suspended concrete floor

Postby kevtubb » Fri Aug 03, 2007 10:11 am

I have recently purchased a house (9 years old) for which the surveyor advised there was insufficient ventilation (just 1 air brick) for the suspended concrete floor - witha longer term risk of condenstaion and resulting damage.

Can anyone advise what is involved in correcting this? Is it a case of taking out bricks and replacing them with air bricks, or something more complicated requiring them to somehow be duct in under the floor?

Really appreciate any views,
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Postby mikric » Sun Aug 05, 2007 5:40 pm

have a look for telescopic air vents in your builders merchants once you have seen them you will have a good idea on how to fit them they are the standard modern norm for new builds etc .
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Postby TheDoctor5 » Thu Jan 22, 2009 9:06 am

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Postby pmgltd » Thu Jan 22, 2009 5:55 pm

I am pretty sure that the building regulations 9 years (part C) did not require the provision of sub floor ventilation - unless there was potential for the accumilation of ground gases in the sub-floor void.

Fitting additional air bricks, would require the removal of existing bricks and the provision of a telescopic ventilator to duct the air flow to the sub-floor void. An air brick is then provided in the external wall. A cavity tray should also be provided in the cavity over the ventilator.

Todays regulations would generally require the provision of 75x225 plastic air bricks at approx 1.8m centres.

Any internal walls which extend below the floor level, would prevent the effective cross-flow of air, therefore, carefull detailing would be required to ensure that suitable cross-ventilation is achieved

Hope this helps
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