18 January 2016 Last updated at 20:09 GMT
Ben Frost, 27, barricaded himself into his girlfriend's flat in Princetown on Dartmoor on 18 January.
He was arrested two hours after breaking through the roof, Plymouth magistrates heard.
Unemployed Frost of no fixed address admitted two charges of causing criminal damage and two of threatening behaviour.

A Vauxhall Astra and a Peugeot 206 were involved in the crash on Blackburn Road in Sheffield at 01:00 GMT.
Joshua Fothergill, 19, of Rotherham was in the Astra and died at the scene as did Liam Parkin, also 19, of Sheffield who was in the Peugeot.
A 20-year-old man, held on suspicion of causing death by dangerous driving and failing to stop, has been bailed.
Three other men who were travelling in the Peugeot were injured and taken to hospital for treatment.
They were a 24-year-old and an 18-year-old from Rotherham, and a 21-year-old man about whom no other details were released by police.

Mr Opstelten had said the trafficker was paid less than he actually was for money wrongly confiscated by the state.
He also said details of the payment - authorised by Mr Teeven as prosecutor - had been lost, but this was not so.
The resignations are a blow to the Liberal party as it faces an election.
Mr Opstelten and Mr Teeven are both from the conservative wing of the party, which faces a challenge from Geert Wilders' far-right Freedom Party in provincial elections this month.
The resignations are also expected to place a strain on the Liberal's coalition with the Labour party, which has been very critical of Mr Opstelten and Mr Teeven.
The justice minister had claimed that a convicted drug trafficker, Cees Helman, was paid much less than the compensation of 4.7 million Dutch guilders - worth â‚¬2.1m (Â£1.5m; $2.3m) in current terms - that he in fact received.
He also said that the details of the payment had been lost.
On Monday, however, Mr Opstelten said a record of the transaction had been found.
"This information could have been found earlier," he told reporters. "I take full responsibility for this and have just now offered my resignation to the king."
The payment was made after the authorities were unable to prove that money they had confiscated from Helman had been obtained illegally. Mr Teeven, who was a prosecutor at the time, had authorised the settlement.
The payment was not illegal. However, both ministers said the misinformation had made their positions untenable, Reuters news agency reports.

According to The Hollywood Reporter, the film will not be a biopic but an action adventure set in the 1970s.
No writer, director or actors are yet attached to the project, which will be produced by the brains behind the Twilight and Maze Runner franchises.
Born Stanley Lieber in 1922, Lee teamed with artist Jack Kirby to create such iconic comic-book properties as the X-Men, the Hulk and the Fantastic Four.
Spider-Man and Daredevil are among the other characters he co-created.
Lee's cameo appearances in the Marvel blockbusters have become a staple of the series, while his "Excelsior!" sign-off is legendary in fan circles.
Mary Bowen and Wyck Godfrey, co-founders of Temple Hill Entertainment, are on board as producers of the 20th Century Fox picture.
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A man who sparked a drug-fuelled roof-top siege after breaking up with his partner has been given a suspended prison sentence.
[NEXT_CONCEPT]
Two teenagers who died when two cars collided in the early hours of Saturday have been named by police.
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Dutch Justice Minister Ivo Opstelten and his state secretary, Fred Teeven, have resigned after misleading parliament over a 2001 compensation payment to a convicted drug trafficker.
[NEXT_CONCEPT]
A film about comic book maestro Stan Lee is reportedly in development.