Screw size - squeaky stairs

[jacko555]

I have squeaky, old stairs. At least 100 years old and repaired / new treads added in a odd way.

Each tread is now made of 2 pieces of wood and moves/squeaks independently of each other.

Plan is to cut 18mm ply and glue and screw this to the underside using this https://www.screwfix.com/p/evo-stik-polyurethane-wood-adhesive-310ml/40778

Once done, then add 44x44mm batons glued /screwed through the ply and tread, and glued / screwed to the risers. This is to replace the missing glue blocks and wedges.

Like this but up into the tread as well as into the riser.

Finally glue and screw more batons to the ply and stringers to support the ply.

I'm hoping this will sort out the creaks.

Questions:

1. Is the EVO-STIK POLYURETHANE WOOD ADHESIVE a good choice of glue? Is there a better one?

2. For the screws going through the ply into the treads. Ply is 18mm, treads are 23mm. Total thickness 41mm. What length screw and what diameter would you suggest? 30mm or 35mm? What width? I will drill pilot holes.

3. For the screws going through the batons, ply and tread (23mm + 18mm + 44mm) =85mm. What length and width screw?

Cheers!

 

[Deleted member 174758]

DON'T use any form of polyurethane glue - it will expand (foam-up) and push the plywood off the boards you are trying to stabilise. You are better off using a non-foaming glue like Everbuild D4. For the plywood - use 4.0 x 35mm screws and also put a couple of screws in near to the front to pull the plywood up to the tread before applying the glue block - just don't oversink them. For the 85mm thickness use 5.0 x 80mm screws, but make sure you rub glue the battens properly to the backs of the risers and undersides of the plywood before screwing in place. TBH I'd also put a few screws through the fronts of the risers as well,m something like 4.0 x 35mm

Surely your existing stairs have glue blocks beneath them, though? How do you intend to deal with those?

BTW, the backs of the treads may well not marry with the risers in the way your drawing shows - there are several methods of making that joint so the suggested repair (as in the drawing you posted) may not be appropriate. Also consider knocking the wedges in tight if they are loose and replace any that are missing (assuming that there are wedges under there!)

 

[jacko555]

Surely your existing stairs have glue blocks beneath them, though? How do you intend to deal with those?

I see the ghost marks of where lived 2 per tread.

Not a single one remains on the entire flight, probably explaining the squeekyness.

Thank you for the tips.

 

[Deleted member 174758]

When I was involved in refurbing houses (a while back - mainly terraced house, although some of those were pretty big) we used to get some Victorian builder's horrors plus the odd DIY nightmare like yours. Almost without exception I deemed them as not worth the effort and simply replaced them with a new stair on a like for like basis (which is permitted). I reckon that once you get past spending a couple of days repairing them a new stair is going to be cheaper with less come backs later on (but bearing in mind that it's my trade and making up a basic straight flight was maybe 1/2 to 1 days work most of the time with maybe 1 man day, or rather 2 x 1/2 man days, to install)

 

[jacko555]

I reckon it'll take me half a day to glue and screw and I've spent near £100 on materials.

Part of me would love to get replacement stairs built, however I don't have the skill to make one and a decent carpenter would cost thousands in labour and material.

Not to mention (if you ignore the grotty paint) it looks fairly grand and aged. The pantina is part of the charm. It's 1m wide, has a midway landing with a 1.5x3m window and almost comical newel posts. Far grander than called for.

Replacing it would be a shame. I just want it to not groan every time I climb it. Properly prepped, painted with a sisal boucle runner and it'll be perfect

 

[Deleted member 174758]

Go to a CNC place and it's a few hundred for a straight flight. It's when you start adding hand rails, ballusters, kite winders, etc that the prices go up