From UK AIC No. 80/1962 we find this table:
Calculated Effect on Take-off Performance of a Uniform Layer of Slush or Water on a Runway
Aircraft type and % Increment to the Take-off Field Length required for a Depth of Slush or Water of 0.5" (15 mm).
Boeing 707-436 20
Comet 4 20
Ambassador 50
Argonaut 45
Britannia 30
Constellation 35
DC-3
(Fingertrouble - I try again)
From UK AIC No. 80/1962 we find this table:
Calculated Effect on Take-off Performance of a Uniform Layer of Slush or Water on a Runway
Aircraft type, and % Increment to the Take-off Field Length required for a Depth of Slush or Water of 0.5\" (15 mm).
Boeing 707-436, 20
Comet 4, 20
Ambassador, 50
Argonaut, 45
Britannia, 30
Constellation, 35
DC-3, 20
DC-4, 45
DC-6, 30
DC-7C, 30
Bristol 170 (Freighter), 20
Hermes, 45
President, 30
Prince, 30
Viscount, 50
Vanguard, 20
Viking, 20
Note.-
These figures are based on the assumption that, for nose-wheel aircraft, the nose-wheel is kept in contact with the runway until the aircraft is rotated. Smaller increments than the above may be justified in special circumstances.