Replace floorboard nails with screws?

[Spoilt Victorian Child]

I have a handful of loose floorboards from a rewire/replumb. I asked the builder not to nail them all down again as I think I'd prefer screws, for if the boards ever need lifting again it's less likely to split them.

My question is, what screws should I use?
Is it ok to use the existing nail holes or is that asking for some sort of trouble?

The boards are 18mm thick and are not tongue & groove.

The room I'm doing at the moment will be carpeted, and the boards aren't in great condition so unlikely to ever be on show.

Later I need tackle the hallway, which will have sanded/varnished floorboards eventually, so need screws which will look OK/go unnoticed.

I can't believe I'm starting a thread about frikkin screws! But I just wanna get it right first time and be happy.

 

[plasticpigeon]

I'm not sure there is a right way. I would try and use the old holes and see what happens. If the holes are too big, make new ones! If the room is to be carpeted then it doesn't matter. Floor boards on show are more problematic. I have used normal size 8 posidrive wood screws, but have sunk the heads by a couple of mm, which involved drilling a slightly bigger hole that the head can sink into. The best way is to use a stop collar on the drill bit. I haven't finished the boards yet, but I am planning to fill the holes with coloured wax to help them blend in.

 

[paulc]

I've got a few floorboards that had been lifted in the past for plumbing and electrical work. Most were screwed down using the original nail holes, and they creak & move every time I step on them. When I have need to lift the carpets over the affected boards, they are being screwed back down with 38mm long plasterboard screws avoiding the original nail holes and any pipes or wires.

I suppose the original nail holes could be reused if the holes in the joists were plugged with wooden wedges, but quite a few of my boards are split at the ends...

 

[bennoa1]

You should be OK with countersunk screws. I only use brass or stainless ones now after lots of screaming and shouting trying to remove rusted up steel ones, same with the cars, just use stainless bolts/self tappers. If you use stainless you may need a pilot hole as they tend to be a bit softer.

 

[Hobden]

Spax flooring screws seem to have a good reputation if your pockets are deep ...

 

[MikeG]

You should be OK with countersunk screws. I only use brass or stainless ones now after lots of screaming and shouting trying to remove rusted up steel ones, same with the cars, just use stainless bolts/self tappers. If you use stainless you may need a pilot hole as they tend to be a bit softer.

Brass and stainless are both weak metals, particularly the former. If they get stuck, you will easily snap the head off trying to unscrew them. I would absolutely avoid brass personally, for this reason. Stainless, as you say, approach with caution. Mind you, if the timber is high in tannin, such as oak, then stainless is a must as oak "eats" mild steel for breakfast.

 

[88v8]

If they'll be visible, brass. Slot-head, ie traditional. Pozis in the period house set my teeth on edge.

If not visible, then upstairs away from damp I'd use steel.
Downstairs where likely to be damp, back to brass,

Someone said ''' you may need a pilot hole'... The only time you can get away without a pilot hole is with modern screws in rubbish wood. In old timber, I always always drill a pilot hole. Indeed, for large screws the pilot may involve up to three different drill sizes so as to make the hole tapered. No! That should be four drills. I forgot the shank. Plus a countersink bit of course. It takes time to do things properly.
If I had a lot of screws to drive I used three drills, a hand drill with the shank bit in it, an electric for the countersink, and another hand drill or perhaps my mains drill with the pilot drill(s).

[Confusing, isn't it, that we use the same word for the drill that drills the holes and the drill that powers the drills.]

The screws need to be tight so the pilot needs to be the right size - rather than screwing the brass screws in and out to test as you drill the pilot, use a steel screw the same size, then when you are happy with the pilot, put in the brass screw.
The screwdriver needs to match the screw. If the screw had a wide slot the blade of the screwdriver needs to be thick so there is no chatter otherwise the screw head will burr.

You may be able to reuse the nail holes but I doubt it. The original nails would/should have been driven in on the skew, whereas your screws need to be upright so the heads sit flush and parallel to the surface.
Drill new holes.

Your boards at ¾" are quite thin. I'd use 2" x 10s.
http://www.ebay.co.uk/itm/No-2-3-4-6-8-10-12-Solid-Brass-Slotted-Countersunk-Head-Wood-Screws-All-Gauges-/161260393647?var=460299713986&hash=item258bde54af:m:mFUyCFjdHlEWr8tRpmjUUBg
Or if the boards are out of the way of foot traffic, perhaps 2" x 8s.

If they creak - good. It's part of the period ambience.

When drilling beware of services.

Ivor

 

[Spoilt Victorian Child]

Thanks guys, esp. Ivor, I knew there'd be some science to this.

The floorboards are pine. The whole house creaks like a ship so I'm not gonna attempt to solve that side of things, just want ease of access for the future.

The 2" x 10s screws mentioned - what are those numbers/measurements in relationship to?
How do the 2" x 8s differ?

 

[Hobden]

The 2" x 10s screws mentioned - what are those numbers/measurements in relationship to?
How do the 2" x 8s differ?

2x10 means 2" long and number 10 gauge, which means about 5mm in diameter, or about 50mm long by 5mm diameter, which is how you'll probably find them described in Screwfix etc. The bigger the gauge the thicker the screw. A 2x8 is 2" long and about 4mm in diameter, so thinner than a 2x10.

 

[CliffordPope]

Pozis in the period house set my teeth on edge.

Ivor

Like people saying "drill" when they mean "bit"

 

[Keith Bowman]

I too would only use slotted screws - but the slots must be aligned with the run of the board

 

[Feltwell]

I agree with Ivor. The nail holes won't be the right size or shape to take a screw head, if they were created with cut clasp nails (most likely). I'd consider filling the holes with a pine coloured wood filler and then re-drilling and countersinking, if they'll be visible. Getting the nails out may damage the boards, you may find you're better off carefully punching them through once the boards are lifted rather than trying to knock them out.

Brass countersunk slotted-head screws are I think the only way to go to look visually acceptable - the brass will dull down and blend in quite nicely after a while, at least on any bits that feet don't regularly touch - and personally I'd use No.10 gauge, No.8 is a bit light for floorboards.

Experiment though - you may find that using the old nail holes means the screws aren't getting a god enough purchase in the joist underneath. If you really wanted to then you can drill out the holes in the joist and glue a dowel into them first - but that's a lot of faffing around just for floorboards! I've done that successfully in door frames where the hinge screws can't get a purchase any more, drilled the hole out and tapped a beech dowel in with a bit of wood glue before re-drilling for the screw - works OK I find.

Another option, depending on how you've lifted the boards, cut the nails off underneath and put the screws in new holes alongside the old nail heads. Will give a better result I expect, for all the reasons above.

As well as drilling a pilot hole and then countersinking, if using brass screws then I'd drive a modern steel pozidrive screw in and out first - very quick to do with a cordless impact driver - and I like to lubricate the brass screws so they go in easier, as you'll have to screw those in by hand. I've got a pot of silicone grease (meant for car brakes!) that I use because it's clear and not messy, but you can use all kinds of stuff really - Vaseline would work OK - just helps the screw go in and makes it less likely that you'll damage the head.