Walls Damp Tanking

Tanking with solid wall insulation Remove existing fixtures and fittings and set aside for re-use where possible. Remove existing skirting boards, wall and floor tiles, floor coverings, services, and built in wardrobes from the rear bedroom. Disconnect the electricity and remove the distribution board in #specify location#.  Hack off wall plaster from floor to ceiling to expose brick/blockwork, in the following areas: - All external walls - All partition walls - All party walls - This includes the front cupboard under the external steps. Remove built in, non-structural timbers which would be vulnerable to rot if sealed behind damp-proofing. Embedded structural timbers should be replaced with materials less sensitive to moisture. They can only be retained if they are sound and of durable material and if dampness can be minimised in the supporting structure. The walls to be sealed must be firm and relatively even, and its surface free from voids, gaping cracks or ridges. Bitumen, oil, grease or remains of paint have to be removed by suitable means. Laitance and unsound concrete has to be removed by bush hammering or sand blasting. The substrate should be well pre-watered and slightly damp at the time of application. Allow for dubbing out/keying to provide a smooth surface for the application of a cementitious mortar tanking system. Services must be run in recesses in the walls. Add a Cementitious Mortar Tanking/Damp Proofing system to the following wall areas: - All external walls.  - All partition walls. Timber door frames in partitions must be protected by continuous damp-proofing around the sides and base of the opening  - All party walls. An envelope treatment will be required around the chimney breast.  - The damp proofing layer must be taken into the door and window reveals to abut the door or window frame. Interior sills, of durable or preservative-treated timber, should be affixed to the lining wall. - Isolate the door and window frames from masonry by a physical damp proof course which laps the wall damp-proofing. Dependant on the specific manufacturer’s instructions, this will include: The application of a waterproofing slurry mixture to a minimum of 1.5mm for ground moisture sealing, 2mm for pressureless surface water seepage and 3mm for areas of high water pressure seepage such as underground room areas. The application of the waterproofing slurry with a masonry bush, trowel or spray equipment and a finish with a thin rough cast of sand and cement in the ratio 3:1. The application of the cementitious, ready mixed, efflorescence-free surface waterproofing and repairing mortar in a minimum of three layers between 6-12mm thickness in accordance to manufacturer’s recommendations. The final coat to be left unfinished but floated smooth ready for the application of insulation board. Fix solid wall insulation to the internal side of the external walls to provide a u value of #specify value#. The insulation boarding shall be fixed in such a way that the cementitious layer is not punctured. Restore the removed fixtures, fittings and surface finishers such as wall tiles and redecorate. Special wall fixings must be used to ensure cementitious layer is not punctured. All damp proofing works are to be carried out by a competent specialist contractor, for example, who is a member of the Property Care Association (PCA). A guarantee certificate on completion shall be issued and a copy forwarded to the council. There are alternative methods of tanking – The Environmental Health Officer will accept any alternative scheme provided by a damp specialist who is a member of the PCA, provided that appropriate data sheets and methodologies are provided for the system chosen.