Stair problem - Gap between tread and riser

[STephen]

Hi there

I am replacing the carpet on the stairs of my victorian terraced house with a runner. This will leave a margin of about 6 inches on either side where the 'naked' steps are visible.

Unfortunately on three of the steps, the riser has slipped down from thne tread about half an inch on the right hand side. I'm not sure how to go about filling the gap. Ideally I'd like to insert a wedge of wood but it would have to be very long and thin so instead I was toying with the idea of just filling the gap with flexible polyfilla and inserting one screw to provide some stability.

What do you think? Is there any other way to tackle this?

Stephen

[Albatross]

Have you tried going under the stairs to tap the offending risers back into place and then secure them. I would also check to ensure none of the tread or rise wedges have come loose which may account for the rises slipping in the first place

[STephen]

Unfortunately I can't get to under the stairs as the underneath has been plastered long ago.

Should I think about removing this plaster? Its just in a cupboard so removing it wouldnt cause a visible change.

[Newshound]

It does seem an awful lot of movement, I think I'd expect it to make the stairs squeaky if not flexy. I'd be inclined to explore and try and fix it properly.

[John Rumm]

How about temporarily screwing a block of wood to the riser in the middle (where the carpet will ultimately hide the screw holes) and then using the block to tap the riser back to where it ought to be?

Failing that, a bit of Scotia moulding under each nosing would hide the gap.

[STephen]

The stairs dont squeak at all. They are fixed securely in the stringer and the gap between tread and stair is only on the right hand side.

However there is a certain amount of flex in the board especially in the middle.

I inserted a screw down from the tread into the riser hoping that it would either pull up the riser or make things a bit more firm. It didnt pull up the riser at all but seems to have provided some stability at the right hand side.

I was going to see if I could have some wooden wedges made up to fill the gap so that the board doesnt flex at all but I'm worried that all i'm doing is providing a temporary fix and what I really need to do is fix it properly, even if it means pulling down the plaster that covers the underneath of the stairs.

I take it you think I should go for the permanent fix.

[STephen]

A previous owner has actually drilled 2 inch holes into the middle of every riser so I tried to insert the claw of the hammer into the hole to pull up the riser but that didnt work.

I take it that it needs a fair amount of force to lift the riser. If i did manage to lift the riser, i guess it would have to be held in place with a screw or two.

As I mentioned in a previous post I'm leaning towards actually pulling doiwn the plaster under the stairs so i can get direct access to the offending steps.

Do you think that is the best idea?

[John Rumm]

Yup, I would anticipate you would need to hit it reasonably hard to get them to move.

It is. Stairs are usually built from the underside - so that is where you really need to be to do a proper job.

If you look at how I built a set here:

should give you an idea of how they normally go together.

[STephen]

Hi John

Thanks for the pictures. That has really helped me visualise how the stairs fit together.

I see that that the recess in the stringer is actually shaped so that the wedges can be inserted.

It looks to me like the vertical wedge is what holds the riser up. Is that right?

Stephen

[STephen]

Hi again

A picture is worth a good few words so I've also created a little gallery of pictures to show you what I mean.

1: The lowest step that has a gap. Picture 2. Another pic of this step Picture 3: Another pic of this step Picture 4: The other 2 steps where I have filled the gap with flexible fill polyfilla Picture 5: The other 2 steps where I have filled the gap with flexible fill polyfilla Picture 6: The complete staircase Picture 7: Under the stairs showing the plastered 'cover' Picture 8 Under the stairs looking at the lowest steps (covered by vertical coating of plaster)

Hopefully this might help.

Regards Stephen

[Pete C]

Might be worth wedging/jacking the two stringers apart /just a little/ to see if that frees the riser up, maybe the riser is being pinched between them.

cheers, Pete.

[John Rumm]

Yup, well it helps - it ought to be fixed to the back of the tread below as well, and partly held by the arris blocks at the top.

[STephen]

Hi John

What are the arris blocks? Are they the triangular blocks fixed between riser and tread?

Also, did you see the pictures I posted up on the website?

Stephen

[John Rumm]

Yup. Arris (or somethimes aris) is a generic term for a corner of something or the angle formed by the meeting of two surfaces in architecture. Arris rail is typecally 2x2" ripped across the diagonal. Stairs usually have small blocks of it under the riser to tread join (I used longer strips rather than just short blocks on my stairs)

Yup, looks like someone has made an attempt to stick some mastic on the gap. It may look better, but won't add any strength.

The other likely problem you may have is that the risers may be painted into position and hence stuck there. I expect you would need to work from the underside, hammer the treads back into position, take out the old wedges and re-glue them, then hammer those tightly into place. Finally screw the base of the risers to the back of the treads.

[STephen]

Hi John

Thats it! Youve made up my mind that I have to rip down the old plaster and lathe to get at the underside of the stairs.

Do you forsee any problem with doing this?

BTW thanks for your help/advice on this.

Stephen

[sm_jamieson]

I think these days the fire regs require plasterboard under the wooden stairs. My last house had it, current 1930s house does not. I'm sure no-one will miss it. People tramping up and down the stairs may appear to make more noise without it. But to fix stairs properly you have to get underneath. I need to fix my stairs soon ... Simon.

[STephen]

This morning I removed the plaster and lath from under the stairs. Bit messy but all done now.

And I was instantly able to tap the risers back into place.

I'm not sure whether to see if I can remove the wedges and coat with glue before inserting back into place.