Retrofitting underlay from the inside
The ‘protruding lath’ forms a valley and drains any water that has entered to the middle of the area between the rafters (away from the rafters) and towards the eaves.
Affix a batten at the sides (min. height of 2 cm, e.g. 2.5 x 4 [1" x 2"]). Screw a ‘protruding lath’ that is 1.5 - 2 cm thicker (e.g. 4 x 6 [2" x 3"]) to the roof battens in the space between rafters.
Install the membrane
Install SOLITEX longitudinally or perpendicularly, proceeding in turn from one space between rafters to the next. Ensure that the overlaps are waterproof.
Fastening and water flow
Affix battens at the sides. Alternative: Use DASATOP FIX. Ensure drainage through the knee wall into the eave area.
Completed underlay retrofitted from the inside.
Install insulation in the space between the rafters. Install the airtightness layer, e.g. INTELLO, install inner cladding. You’re finished!