Critics have to fight the urge to label Sinéad Ní Mhaonaigh, who likes to avoid categorisation of her work , she tells Aidan Dunne.

Over the past few years, Sinéad Ní Mhaonaigh's spare but richly coloured, boldly stated paintings have built up quite a following. At first glance their broadly brushed expanses, their fresh, invigorating surfaces, suggest affinities with landscape. That, together with the fact that her name is Irish, might encourage a generic identification of her work with the west of Ireland. But although Ní Mhaonaigh uses a limited, tightly organised palette, she doesn't shy away from bright, intense colours, remote from the moody tonality of conventional Irish landscape painting: she has her sights set on something different. And she is east-coaster, born and bred, and still resident, in Bray.

The title of her exhibition at the Mermaid Arts Centre, An tImeall, translates as edge or border, and that of her previous show, Eatramh, at the Kevin Kavanagh Gallery, as an interval or lull, a respite such as a space between showers. In both she is invoking spatial and temporal references of some kind, but the spaces and times remain metaphorical.

The spaces in her paintings may be real or purely notional, mental spaces, but the one thing they don't seem to be is landscape as such. Ní Mhaonaigh, who in person cuts an athletic figure and gives the impression of possessing boundless energy, is keen not to be pinned down. "I love not being specific in the paintings," she says frankly. "I love being evasive and vague."

In one sequence of three paintings, for example, she used the title Stage, but she was taken aback when observers commented on the obvious theatrical connotations of the imagery. The rectangular expanse outlined in the centre of the composition in Stage III could indeed be interpreted as an arena for performance, and the idea of an empty stage, charged with anticipation, is altogether in keeping with the mood of her paintings, but that was the last thing on her mind, she protests.

"I was actually thinking of the stages of evolution within the group of paintings, you know, stage one, two, three . . ." she laughs. "I know it sounds naive, but the thought that it would be taken as a theatrical stage never occurred to me."

It's not that she wants to be evasive for the sake of it, more that she sees the paintings' ability to function as being dependent on their not being tied to a genre, or even too specifically to an image. More than once she says that she's worried about being identified too strongly as something - as a landscape painter, for example, or as an Irish-language artist. She was educated through Irish and speaks it. All her shows so far have had Irish titles. The first was closely related to Pádraic Ó Conaire's Scothscéalta.

Still, she observes: "The Irish language is a huge part of my life, but it's not everything and it doesn't define what I'm about. I would hate to be in that position. I think using Irish titles . . . it's something that you work through. In a way I feel I probably don't have to do it any more." But, she adds, she loves the texture of the language.

Her approach to Ó Conaire was anything but illustrative. As ever, her paintings visualised an ambiguous, indeterminate space. As Catherine Leen has written, in this context the space can be thought of as equating to the emigrant's state of dislocation. It's a state of uncertainty that clearly appeals to Ní Mhaonaigh, the difference between potential and actualisation, longing and satisfaction.

There is something like a recurrent iconography in her painting, albeit in a very sparse, outline way. It includes a vessel shape, central expanses or perhaps even buildings bounded by various kinds of linear markings, and the use of rhythmic patterns and intervals.

The surfaces are often thickly, irregularly textured. They are built up layer on layer, and on occasion scraped drastically back as well. It's a process of "rejecting and accepting". She wields a palette knife with vigour in both respects. "The knife. I love those incisions. They're like moments of clarity."

The vessel or chalice unmistakably recalls early Christian Irish artefacts. A ritualistic quality is suggested in the linear patterning. Yet the social and cultural spaces suggested by these symbols is pointedly empty. The paintings are not about a nostalgia for lost certainties, in other words.

Ní Mhaonaigh is, she says, attuned to a sense of "a living, mythical history", a richly textured narrative tradition wrapped up with the physical and cultural landscape. She points to Ó Conaire in this regard. She shies away from some of the more obvious icons of an Irish cultural tradition.

"It's not that I wouldn't have a high regard for them, but there is this feeling that we have just exhausted Yeats and Beckett. It's hard to see around them."

She has a studio in Henrietta Street in Dublin city centre, where she works on several paintings at any one time.

"I'm a bit of a workaholic, and I've come to realise that the trade aspect is so important in painting. Every aspect of it is important. I don't use reference material any more, for example, I love thinking in the work as it goes along. I would hate to be in the position where I felt the content is more interesting than the work."

Pressed, she goes along with the idea that the paintings might in some sense be "records of journeys". Hence her painting Pilgrim I, perhaps, and those vessels, and the constant evocation of an indeterminate space or "non-space": an edgy, provisional, potential space, one that it is up to us to define.

An tImeall, paintings by Sinéad Ní Mhaonaigh, is at the Mermaid Arts Centre, Bray, Co Wicklow until Nov 25