Most drummers are unused to being the centre of attention. Radiohead's Phil Sel­way is no different; it's taken him 20 years since the inception of Radiohead to finally find his own voice. But it has been worth the wait.

His debut solo album, Familial, is a tender affair featuring Selway's hushed vocals and acoustic guitar. Its creation has been con­voluted, taking in a side project with Crowded House's Neil Finn, but sadly also the sudden passing away in 2006 of his mother, Thea, to whom Radiohead dedicated their last album, In Rainbows.

Selway certainly recognises the oddness of the situation. "You learn to write songs when you're a teenager, or when you're in your 20s, so you have a particular slant from those experiences," he muses. "Coming across a new songwriter who's starting in his late 30s, that's a different slant on things."

Before concentrating on drums, the Radiohead founder had written lyrics as a teenager, but when the group started he found himself overshadowed by Thom Yorke's intense style of composition. "When we first started as a band, I'd bring stuff in, but there's no dearth of material there," he smiles. "So I didn't really write anything for a good decade and a half."

It was three years ago, on the verge of turning 40, that Selway took his songs more seriously. "It was now or never, that thing of looking at your list of life's 'to do's. It had been in there for a little while, but those big changes, like my mum dying, those things shake everything up and lyrically everything came out of that sense of taking stock."

A key similarity between his solo work and Radiohead is a tangential quality to the writing. He admits that in the first song where he found his voice, the stately 'Broken Promises', he directly addresses his departed mother by reminiscing about his own youth.

"I got to the end of it and thought, 'that rings true'. It gave me the confidence to believe I could bring all these scraps of lyrics together, without thinking too hard about them. Throughout the songs, there's a warmth to them, but I didn't want them to feel mawkish or over-precious. So there's an honesty in that one, about the process of working through grief and being at that point with your own children where you look back at your own childhood. It actually makes you a lot more generous-spirited about it all; you understand the complexities."

Selway quietly laid down some demos, but was not sure he should sing them in public until he collaborated with Finn. He had appeared behind the drum kit on the Crowded House frontman's 7 Worlds Collide, the 2001 album for the charity of the same name. Then he returned for its follow-up, The Sun Came Out – a studio project written and recorded over a fortnight in New Zealand during January 2009. In the august company of Johnny Marr and Wilco's Jeff Tweedy, Selway contributed two numbers, 'The Ties That Bind Us' and 'The Witching Hour', both of which have been reworked on Familial.

Even when he turned up to work on The Sun Came Out at Finn's Auckland studio, the drummer had no intention of contributing his own lyrics, but Selway fell under the spell of the Kiwi's can-do attitude.

"There was so much going on in the studio, an explosion of creativity and activity, I just found my spot in there. I took up residence on Neil's staircase and hadn't sung to anybody before, but something felt right. People started picking up on it as they walked past me and suddenly this band fell into place very quickly." He was later able to call on some of his Auckland collaborators to record Familial: veteran solo artist Lisa Germano, former Soul Coughing bassist Sebastian Steinberg and two members of Wilco – drummer Glenn Kotche and multi-instrumentalist Patrick Sansone.

An intriguing side-effect of his work outside Radiohead is that he feels more positive about his regular band and the idea of recording another album, a feeling that Yorke must share himself. After In Rainbows, he suggested the band would not make another album, though that outburst has been forgotten. "We say that after every record, don't we?" Selway laughs, though he admits that side-projects help.

"We have our fairly defined roles within the band and you try and develop within them, but they are fixed. Working outside the band, you always gain a broader view and you get stuff out of your system, which prevents some frustrations coming into the process of working together. And you appreciate what you've got."

'Familial' is out now on Bella Union Records