urgent help with building a step, please! Post your questions and get answers regarding all areas of drives, pathways and patios

[manic monkey]

Hi. I'm building a big step today, 2100 mm across, from a lounge into a kitchen. The step will be made of ply then covered with hardwood. I don't want to leave an expansion gap with the hardwood as the step is within an arch and the two sides of the arch aren't exactly the same size (dodgy builder). Any skirting/quadrant I put over a gap will only emphasise this point. Am I ok to have only 1-2 mm expansion gap on each side of the step? thanks

[speedwell]

Hardwood expands and swells more in the winter months. Even if central heating is on, the abient moisture content in the air is higher november to march.
If you lay hardwood now with 2mm gap it is only gonna swell. You could chance 5mm each side and put a little quadrant beading on.
The next appealling is to blind screw the last lengths of hardwood planks between the arch every 4". It will still swell a little but might just do the trick.

The best answer is to use engineered flooring, Thid is dimensionally stable with hardwood finish and is used in hot/cold rooms like conservatories for this very reason. But you still need a little gap around the edges.
speedwell.

[manic monkey]

Thanks. In the end I had to do the work so chanced it with a 2-3 mm gap for the smaller top step but cut into the plasterboard for the big bottom step. Now I'm holding thumbs! Boards are solid wood as engineered won't give a decent face to the step. I've used pink grip as well as wood glue along the edge and secret nailing, so I'm hoping they'll have to be pretty damp to shift...............