Builder and part time barman Anthony Bird, 49, has been cleared of murdering partner Tracy Kearns after he found out that she was having an affair.
After a retirement of 11 hours and 20 minutes the jury found him guilty of manslaughter by a ten to two majority.
Mr Justice Clive Lewis said that he would sentence Bird on Wednesday.
He said “I think we need time to reflect on the verdict given.”
The judge said that it would inevitably still be a period of custody “measured in some years” to reflect the unlawful killing of an innocent victim.
The defendant did not react when the verdict was returned.
Suspicious Bird lay in wait outside her mother’s home in Llandudno one Sunday morning in May and watched as she returned home from two nights at The Imperial Hotel in Blackpool with lover Andrew Jones.
Mold Crown Court heard how he appeared to take it well, suggested that they stay together for the sake of their two young daughters, and even spoke amicably to Mr Jones, a regular customer at the club where she worked part time as a bar maid.
Bird said he wanted to talk to Tracy after she returned home from her job as a part time barman at The Sandy Cove Club in Kinmel Bay, where he also worked as a builder and barman.
She entered their home in nearby Cader Avenue at 9.20pm. and was never seen again.
Prosecuting barrister Ian Unsworth QC said that it was a sustained and prolonged attack in which she suffered 40 separate injuries.
She had been strangled and possibly smothered – and Bird told family and friends that she had a new man and had simply walked out.
The truth was that he had killed her, cut her clothes off, wrapped her naked body in plastic and stuck her in a tree house, or Wendy house, which he had previously made for the children.
It lay there for three days.
But her family and friends knew that Tracy would never have left her two beloved daughters and quizzed him.
When the police were told, Bird dragged her body through the house, including one of the girl’s bedroom, into his trailer.
He covered the body with debris and left the trailer behind a high wall at the club where they both worked.
The prosecution said that he was desperate to get rid of the body and had been seen riding around looking for possible disposal sites.
After police found the body, Bird changed his story and claimed he acted in self-defence.
He said that she came at him with a pair of scissors and threatened to kill him, he pushed her back and restrained her by the neck, and that she died.
In evidence, he claimed that it was necessary to kill her in order to defend himself.
Bird also alleged she humiliated him by telling him of the sex she was having with her new lover and the kinky underwear that she wore.
Defending barrister Gordon Cole QC said Bird admitted the killing but claimed that he had simply lost it. He urged a manslaughter verdict.
The prosecution said that he was making up false allegations against her – to blacken her character – in a bid to save his own skin.
Bird denied murdering Tracy Kearns, a former Asda manager, who he met in work, between May 7 and 11 this year.