Ventilation: The Delta-PT membrane can be ventilated via the ventilation profile, which is placed at the top and bottom of the system. Other options include; Ventilating the ‘air gap’ by installing a passive air vent through an external wall which has access above ground level. This acts as a vapour pressure release duct without cooling the cavity.  Contact our technical department for further advice. Tel. 01992 523811

4. Plaster/render options

Option 1 Two coats of Tarmac Whitewall High impact plaster are applied to a total thickness of 15mm. The first coat is trowel applied and is pushed into and behind the mesh filling the stud structure and giving a cover of approx 6mm. This should be scratched to create a key for the second coat.

After 24 hours a second coat should be applied to approx 9mm. The second coat should be sponged and trowelled to a finish.

Tarmac Whitewall plaster is based on mineral anhydrite (anhydrous calcium sulphate). This product has high impact qualities also.

Option 2 Carlite bonding can be applied in two coats. The first coat 5-7mm is pushed into the mesh and is scratched to create a key for the subsequent 8-10mm coat which can be applied 24 hours after the first coat has been applied.
A skim finish of 3mm is applied to create a smooth finish.

Note: Carlite bonding is not suitable for areas where high humidity is expected to persist, i.e.: bathrooms, kitchens, or where condensation is likely.

Option 3 Two coats of cement/lime/sand are applied in a 1.1.6 mix respectively. Each coat should be approx 7-8mm to a total thickness of 15mm. A minimum of 7 days should be left between coats to allow for stress cracks in the first coat, which are created during the drying process.

Option 4 Using the dab fixing method, sheet finishes such as plaster board or thermal insulation board can be dab fixed using Drywall dabs. Normal dry lining procedures apply, and 50% of the wall area should be covered with adhesive dabs, including strips across the top and bottom of the wall. The dabs should be placed directly over the lath plugs fixing heads.

No other plastering specifications would be recommended.

5. Heritage

This system has been used on many heritage type structures. The two main benefits being that it is sympathetic to the structure, and that it is also a reversible process, unlike conventional coating type systems.
All types of structure, suffering the effects of dampness, contamination from salts, carbon deposits, will benefit from the use of the Delta-PT.

6. Note - This information is for internal wall use only. For advice on external (outside) applications, contact the manufacturer.

The Delta-PT system can be considered as a safe method of work, with no significant risks, and is not affected by C.O.S.H.H

However when drilling and hammering, the use of safety goggles and ear defenders or ear plugs, are recommended.

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