Re-Roofing a Building when in Use: Vue Cinema Doncaster

When this multi-screen cinema on the outskirts of Doncaster needed a section of its asphalt flat roof refurbished as part of extension and maintenance works, the owners needed the building to stay open to the public throughout the installation.  In this post we explain how this was done.

The 750m2 central cinema roof which needed repair was located right above above a stair and lift core and projection rooms, and was covered with a great deal of mounted plant, equipment and trunking, making it too disruptive and noisy to take up and replace the existing asphalt. A cold-applied liquid product would be much more effective in any case, in order to avoid any complex edge and penetration detailing associated with membrane products.

Many cold-applied liquids contain solvents. Not only was the client concerned that these might pose a health and safety risk, but any odour might put off customers. With the cinema screens in operation a few feet away there was potential for the fumes to enter the building through air conditioning intakes on the roof.

An odour free waterproofing liquid

With these concerns in mind our specification manager Cameron MacAndrew chose to recommend Hydrostop AH-25, a wet-on-wet cold applied liquid waterproofing system that contains no solvents or isocyanates, and also has a very low VOC content.

‘Hydrostop AH-25 emits no fumes and no odour, which meant the cinema could continue business as usual for the week. Installers like AH-25 because it goes down wet on wet in a single pass install and no additional respiratory PPE needs to be worn at installation.’ – Cameron MacAndrew

For the installation process, the roof was first cleaned; then a base coat of AH-25 was applied, into which a 110gsm layer of polyester reinforcing fleece was embedded. The second coat of liquid can be applied immediately, saturating the reinforcement and completing the waterproofing. AH-25 is totally impervious to standing water, and as a single component liquid, it does not require a catalyst to be mixed into the product before use. The product comes with a 25-year guarantee for SIG’s DATAC accredited installers.

Re-Roofing a flat roof with liquid waterproofing: Vue Cinema Doncaster

Re-Roofing and New Roofing: Quick to Install

The Hydrostop AH-25 liquid roofing system is now even quicker to install. The system can be applied directly to the face of the specified insulation board and only requires the application of a 100mm wide self-adhesive jointing tape to the joints of the insulation, rather than having to apply an entire bitumen carrier membrane over the insulation as some other liquid systems do.

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