Date - August 2019
Summary - The external Courtyard area has allowed tracking of water to lower basement rooms for a number of years. Investigation of the substrate highlighted a debonded and ineffective mastic asphalt layer providing the waterproof barrier, overlaid with a hard packed sand/cement bedding with granite slabs. There was no drainage provision below the slabs and the hard packed sand/cement prevented free flow of water, effectively resulting in a reservoir effect on the surface.
Deck Prepared and Cracks Sealed with Flexible Bandage
2 coat WP with Lap to existing Mastic Asphalt
Primer Coat being Applied for WP Membrane
Protection and free drainage with Cavity Drainage Sheet
Prior to placement of any membrane applications, we also installed a 4” drain outlet through the concrete slab to assist in removing water from the surface, to prevent build-up of water to any significant levels. The WP membrane was coated into the new gulley to provide a seamless layer across the full area.
Bedding layer of 6mm granite for free tracking of water
Caithness slabs reinstated onto granite bedding
Using the 6mm granite and the cavity drainage layer allows free draining of water to the sealed surface. The revised installation should prevent surface build up of water and will prevent the passage of water to the basement rooms due to the excellent bond and flexibility of the application.
Products: RIW Flexiseal & Flexiseal Primer