The number of tower blocks found to be wrapped in potentially flammable cladding has risen to 120 across 37 local authority areas, Theresa May said.
The Prime Minister also announced that the cladding on Grenfell appeared to be in breach of fire safety regulations.
She urged councils to carry out urgent additional safety checks on properties with cladding before waiting for test results at PMQs today.
Every single sample of cladding so far has failed to pass safety tests called in the wake of the Grenfell Tower fire that killed at least 79 people.
At Prime Minister's Questions, Mrs May said 282 good quality temporary properties have been identified for victims of the Grenfell Tower disaster, 132 families have had their needs assessed, and 65 offers of temporary accommodation have been made.
The Government has provided nearly £1.25 million in discretionary payments and will be giving an extra £1 million to a local group of charities, trusts and foundations "which have been doing such important work", Mrs May said.
The PM said she expects to name a judge for the public inquiry into the disaster "soon".
She clashed with Labour leader Jeremy Corbyn over where blame should lie for the safety failures identified in the wake of the disaster.