Wood filler 'flexibility'?

RainbowsInTheSpray

I have a number of very small gaps between the risers and the treads in some old wooden stairs - 1mm-3mm at most. I would get straight on and use wood filler before painting over BUT in some cases there is some very minor flexing of the treads when walking up or down.

Would anyone know whether attempting to fill would be a waste of time? I'm wondering if covering these gaps with some small quadrant dowel or plastic right-angle section might not be simpler.

maisie_cat

When we had similar I used long thin slivers of wood to fill the gap. My dad used to use matchsticks shaved to size and put them a few inches apart to provide support, then caulk across the gap.

twopenny

You can still buy matches.
Long ones available which is even better.
I've used matches for filling all sorts of wooden holes where they shouldn't be.
Strike them or cut off the end obvs.

RainbowsInTheSpray

Thanks guys but, whilst extremely narrow, some of these gaps run the length of the interface between riser and tread... I've never seen a match that long...

GrumpyDil

Use more than one match? 

FreeBear

twopenny said: You can still buy matches.
Long ones available which is even better.

I've taken to using bamboo skewers - They take being hammered in to holes much better.

Lorian

Consider everbuild stixall in the nearest colour to the paint. It's excellent at small gap filling, has great grab, can give forced into cracks from a gun and sets to a rigid but slightly rubbery texture. And it's paintable when dry.

ThisIsWeird

Hi RitS.

Could we see photos of these cracks, please? And, can you get access to the underside, say from a cupboard?

Are the stairs currently carpeted? Will they be?

In general, what I'm going to suggest is to run a nice bead of PVA adhesive along and into any cracks and joints in your staircase - say where treads meet risers. A good dollop, and force it in with yer finger if you can - otherwise just let it 'soak' in under gravity. Once you feel there's a goodly amount in there, wipe away any surface PVA with a damp cloth - ie, from any surface that could be painted later.

Use the stairs - if there's a creaky step, or one that has obvious movement in it, then have a particularly good jump around on that one. But keep using the stairs - each flex will pump the PVA further into the cracks. Add more PVA if it's clearly going in well and doing good - but check it ain't dripping through to the cupboard...

If you can get access to the underside, then slightly dilute the PVS - say 10% with water - and brush it along and into every joint you see. Keep going over these cracks with the brush - force it in as much as you can. 'Stipple' it in, even, if the gaps are large enough for bristles. Wipe away excess as before.

Allow to dry - a couple of days.

See if that reduces flex and movement.

If you can cut suitable slivers of timber to coat in PVA and tap in there to fill the gaps, then that's ideal. But I'd hope that decorator's caulk might now be good enough to make them good. Just be aware that most caulks cannot be sanded, so you need to get it smooth as you use it - a dampened filling knife can work well. And again wipe away any 'surface' excess using a damp cloth before it sets.

RainbowsInTheSpray

Sadly no way of giving a picture but am very grateful for your reply and those of others. I suspect I can probably now tackle this on the basis of them.