atal's Type C system is an internal groundwater management system.  This is usually provided using an internal cavity drain membrane (atal Flo Board 508iR).  The system relies on a cavity between the external skin and internal finish of the structure, groundwater is guided to an appropriate sump and pump system or a suitable drainage outlet with a non-return valve. 

Our internal cavity drain membranes are available in 3mm (walls), 8mm (walls and floors) and 20mm (floor).  Our 3mm and 8mm membranes are available with a mesh backing to provide a ‘key’ for renders, plasters, or Dot & Dab.

Although a Type C system can be used in high risk situations, groundwater should be stemmed to prevent the system becoming overwhelmed.  The outer leaf of the structure should be capable of controlling the amount of water entering the cavity drainage system. 

Where the walls or floors are constructed of concrete or masonry the substrate should be treated using atal Lime Inhibitor, reducing the risk of free lime leaching and obstructing the drainage system. Type C systems should be maintainable and inspected at regular intervals throughout the lifetime of the structure.

We specify a maintenance point every 10 linear metres of channel where possible, external inspection ports may be used on semi basement projects where ground gas is present.  The first inspection should be within 3 months of project completion and every 12 months thereafter.

Our sumps and pumps are specified on a job-by-job basis.  We expect to see one sump per 50m of perimeter channel.  Once the expected flow rate into the sump is established the sump specification can be provided.  Our pump systems are specified to industry best practice, this includes a suitable dual pump system (two inlets and two outlets), with high level alarm and battery backup.  Depending on budget and project needs various upgrades to are available including telemetric systems. 

If you need help or advice regarding any of the Type A, Type B, Type C Structural Waterproofing options for your project or property, please contact us on 01495 717202, or alternatively you can contact us online and one of our team will get back to you.


Thankyou so much to atal for inviting me to todays meeting. I've learnt a whole lot about building physics, Type B Waterproofing and seen some really interesting case studies. The product looks absolutely fantastic and will do very well i'm sure of it!

- Adam Meyrick

I have worked with the guys at Atal for a number of years now whilst working for a number of companies & I would recommend them to other potential customers. I like their proactive approach, customer service, technical knowledge & speedy deliveries. 


If I ever have a problem or detail that needs resolving there is normally  someone available to help, even if it means them jumping in the car & visiting one of our sites at short notice!

- Richard Cleghorn MCIOB, P Chapman Construction

Great service on pricing enquiries for supply and Install, also repairing work - friendly and efficient staff.

- Simon Marsh

I would go with atal for waterproofing on any of my projects!

- Mike Mansfield, Intelle Construction

MJL Contractors Ltd have worked with Atal for a number of years now. We appreciate the professional & approachable manner offered by all of the staff at Atal & we know that if we have a problem we only have to pick up the phone & they will do their best to solve it. Prices are competitive & deliveries arrive as agreed.

- Richard Cleghorn MCIOB, MJL Group Limited

‘’Project architects, RDA liaised with Atal to bring forward a set of waterproofing and tanking details to ensure a water tight lower ground floor level within the setting of the original Bristol Evening Post print factory basement.  Atal provided us with design drawings and specifications founded on their product range and comprehensive industry experience, with which we were able to confidently develop our working drawing package.’’

- Rich Brown – Russ Drage Architects

‘’We had the fortune of being introduced to Atal via our main contractor. We were very pleased with the work they carried out. Although we had some challenges with some leaks with our new build Atal was able to identify the source of the problem very quickly and resolve it immediately. I would have no hesitation in recommending Atal.’’

- Prakash Patel – Hertz

‘’We have completed the groundworks package and almost completed the RC frame package at ‘’3 Glass Wharf’’ in Bristol on behalf of HMRC through Wates Construction. Throughout this project 4D Structures worked alongside Atal UK to ensure the waterproofing elements involved were installed to the highest standard. It was a pleasure working with Atal from design stage right through to the final sign off. They provide a brilliant service from design, supply of materials and also on site help and pre pour inspections. I would highly recommend them and look forward to working with them again in the near future.’

- Jordan Keyes – 4D Structures

‘’Atal have provided consistently quality products, on time at very competitive prices when compared to other high spec structural waterproofing brands. Customer Service has also been consistently, and the inclusion of detailed design documents tailored to specific projects goes above and beyond what other waterproofing companies are often willing to do. Overall, Atal have provided reliable, high quality products and customer service every time we have required their expertise’’ 

- Tom Luscombe – D Wall Construction Services

‘’We have been working with Dave and his team since the inception of the company and it is no surprise at all that the company continues to flourish. The services that Atal offers are unique and un-rivalled in the UK waterproofing industry, and it’s the reason why we as designers and our supply chain partners continue to use them. Keep up the good work Atal!’’

- Gavin Fairclough – Austin Partnership

“We always use Atal for their waterproofing expertise because of their technical ability to provide bespoke waterproofing design solutions tailored to our structural requirements in a proactive and efficient timescale”

- Matt Jones - Vale Consultancy

"Atal have a comprehensive product range, they always offer practical achievable solution and delivery on time results. David is very knowledgeable, and his positive approach is refreshing, hopefully we will continue to enjoy our mutually beneficial relationship, long into the future.”

- Simon Monk - McDermotts

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