Parking area - TarmacDry SuDs system

TarmacDry at Withywood Community Centre, BristolTarmacDry has been used on the parking area at the front. This is a porous paving system that comprises an advanced membrane and underground cavity - it is designed to capture surface water, before either releasing it immediately into the sub-grade, performing a controlled release into the existing drainage (infiltration), or storing it for recycling (attenuation).

TarmacDry is a Sustainable urban Drainage System (SuDS). SuDS as TarmacDry, combine a series of environmentally friendly elements to manage surface water run-off as close to its origin as possible, before it enters the watercourse. Importantly, SuDS remove the need for any additional drainage systems, making them much more cost-effective. 

It provides an alternative to conventional drainage systems and improves outflow water quality. TarmacDry consists of 2 or 3 permeable asphalt layers on top of a granular coarse graded sub base layer. Geotextiles can also be used depending on the job requirements. The TarmacDry system is unique to Tarmac and is patented.


Rainwater collection, Drainage and Soakaways

All rainwater that falls on the roof of both properties will be collected (via guttering and underground pipework) in an underground storage tank in the back garden. Waterbutts at the front of the property will store circa 80 litres of rainwater for use in the garden. Once full, they will overflow into the storage tank.

Once full, the storage tank will overflow into a soakaway designed to take the rainwater to the most permeable layer of soil on the site.

The Code 6 house will use rainwater from the storage tank for flushing toilets.

For more information on TarmacDry please see the deicated microsite (new window)

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Fact 41

Solar hot water panels can provide 60% - 70% of your annual hot water needs.
Source: Self Build ABC