Green Building Forum - 18mm Floorboard options

18mm Floorboard options

Victorianeco — Mon, 08 Jul 2024 11:41:41 +0100

We have 18mm t&g solid timber boards which we are taking out to require and replumb the upstairs.

What would you replace with? 18mm OSB? 18MM P5 boards?

Also a good option to perhaps fit underfloor heating spreader plates?

18mm Floorboard options

tony — Mon, 08 Jul 2024 13:09:04 +0100

Reuse the existing floorboards !

18mm Floorboard options

Peter_in_Hungary — Mon, 08 Jul 2024 13:33:32 +0100

Take then up carefully and reuse.
If you are strapped for cash then take them up carefully and sell them and then use either P5 or OSB. If you are paying someone to relay the P5 or OSB will be cheaper to lay.
(reclaimed t&g floor boards are 20 - 30 quid / m2)

18mm Floorboard options

Victorianeco — Mon, 08 Jul 2024 17:26:39 +0100

These are 40mm planks that have been secret nailed with 3" nails. These won't be salvageable unfortunately

18mm Floorboard options

Jonti — Mon, 08 Jul 2024 19:31:11 +0100

Posted By: VictorianecoThese are 40mm planks that have been secret nailed with 3" nails. These won't be salvageable unfortunately

Use a multitool to cut through the nails and reuse the T&G

18mm Floorboard options

Peter_in_Hungary — Mon, 08 Jul 2024 19:48:24 +0100

40mm t&g planks that have been secret nailed - so no nail holes on the top - Hmm there will be a queue at the door!!

18mm Floorboard options

Dominic Cooney — Tue, 09 Jul 2024 08:15:28 +0100

You can also fit UFH spreader plates from below with a different type of plate. Called “fit from below”
Just a thought.

18mm Floorboard options

owlman — Tue, 09 Jul 2024 10:22:36 +0100

18mm x 40mm T&G; what a strange size?...........Secret 3" nailed on every joist ( 100s of 'em ) ? You are going to need a big bag full of multitool blades to get through that lot.

18mm Floorboard options

Gareth J — Tue, 09 Jul 2024 10:31:19 +0100

A 1mm cutting disc on a small angle grinder will be quicker/easier/less consumables heavy than a multi tool, once you have access. But dirtier.

As painful as it is, I can see why you may decide that total loss is the most cost effective/practical solution.

18mm Floorboard options

tony — Tue, 09 Jul 2024 11:44:49 +0100

I have taken up similar floors by easing up several of the boards (six) at a time, once the nails of the first four are out of the joists each board seperates from its neighbour with it nails still in it, then lift the next section.

18mm Floorboard options

Peter_in_Hungary — Tue, 09 Jul 2024 14:47:19 +0100

A quick dip into salvaged pine floor boards on the internet showed a price of 60 - 75 quid / m2. Perhaps a architectural salvage firm would give you an offer to remove and take away. That way you don't get the work of removal and get a bit of cash into the bargain.

18mm Floorboard options

Jonti — Sat, 13 Jul 2024 11:13:54 +0100

Posted By: owlman18mm x 40mm T&G; what a strange size?...........Secret 3" nailed on every joist ( 100s of 'em ) ? You are going to need a big bag full of multitool blades to get through that lot.

40mm is a very unusual size but if correct then doubtful it will have a nail in every joist with every plank. Yu should manage to get at least 25 nails done with each blade and this would leave the boards in good condition. Much more cost effective than replacing and much greener as well (That is the main theme of this site after all). Having said that, Tony is correct. Once you get the first few up the rest will lift no problem so you should be fine with two or three blade max,

18mm Floorboard options

Victorianeco — Sun, 14 Jul 2024 10:45:45 +0100

It's all up now (in one room)

I think I'm going to tackle the rest of the project from the underside. I think ceiling wills be easier to redo than the T&G floors. We shall see

18mm Floorboard options

wookey — Sun, 18 Aug 2024 12:59:51 +0100

If fitting over UFH plates, I'd use Hideck overlay 18, or screedboard 20 from Cellecta. It's very tough, T&G edges to avoid differential movement, and quite conductive for good UFH heat transfer, but not 'tile cold'.

18mm Floorboard options

Victorianeco — Thu, 22 Aug 2024 13:02:33 +0100

Is T&G essential for 18mm OSB or can you just use OSB in sheet format?

18mm Floorboard options

fostertom — Thu, 22 Aug 2024 22:53:56 +0100

On a noggin, either timber or 100x0.7mm dryliner's galv flatstrap PK screwed @ frequent intervals

18mm Floorboard options

Peter_in_Hungary — Thu, 22 Aug 2024 23:19:46 +0100

Posted By: VictorianecoIs T&G essential for 18mm OSB or can you just use OSB in sheet format?

Posted By: wookeyT&G edges to avoid differential movement

18mm Floorboard options

fostertom — Fri, 23 Aug 2024 06:29:31 +0100

Often at edges/corners you can't keep T&G going - have to cut and butt - then noggins essential underneath. In fact, plain edge sheet is fine, as long as all edges are nogged, much fewer edges if 8x4 sheets, and the flatstrap, as I described, is dead easy compared to timber noggins.

18mm Floorboard options

Victorianeco — Fri, 23 Aug 2024 17:48:20 +0100

Do you have a link to said flatstrap?

I did think full size sheets would be faster and easier and then cut to joists or noggins. Some guidance suggests putting noggins for all the long edges also? Not sure why that would be needed even at perimeters?

18mm Floorboard options

Peter_in_Hungary — Fri, 23 Aug 2024 19:30:13 +0100

On UK spacings of joists with T&G I don't use noggings, with square edged boards noggins on unsupported edges are needed

18mm Floorboard options

fostertom — Fri, 23 Aug 2024 20:06:05 +0100

Posted By: VictorianecoDo you have a link to said flatstrap?

https://ceilinganddryliningsupplies.co.uk/products/0130000000844
or get galv sheet sliced up. For other purposes like plasterboard or sheathing noggins to stud walls/raftering, ditto bent lengthwise to required angle (e.g. eave) is useful - can eliminate much timber that's only there to nail boards to.

18mm Floorboard options

Victorianeco — Sat, 24 Aug 2024 08:48:06 +0100

Great thankyou

Am I right in saying that when using 2400 x 600 t&g OSB I would use these straps under the 2400 section, even if they are locked in and the joists are only 400mm centres?

The Sterling technical data doesn't seem to suggest this, but it does say:
The following general fixing
instructions should be noted:
• Panels must be laid with long
edges at 90° to supports and
short edge joints must be
staggered.
• All short edges must be
supported on joists/studs
or noggins.
• Panel edges must bear approx.
18mm onto joists.
• Nailing must be at least 8mm
from the panel edges.
• All T&G joints should be glued
with a PVA adhesive.
• Panels should be fixed using
approx. 3mm ring-shank nails
or screws whose length is 2.5
times the thickness of the panel
in flooring or 50mm in roofing.
• Whilst not essential, gluing of
the panels to joists increases
the stiffness and strength of
the structure. Additionally
gluing can help reduce any
potential squeaks or creaks.
We recommend you use our
NoSqueak glue.

18mm Floorboard options

fostertom — Sat, 24 Aug 2024 08:53:42 +0100

Posted By: Victorianecousing 2400 x 600 t&g OSB I would use these straps

Such flatstraps shouldn't be needed with T&G boards, except poss instead of timber noggins in awkward corners etc, where there are butt joints.

18mm Floorboard options

Peter_in_Hungary — Sat, 24 Aug 2024 10:21:24 +0100

Posted By: fostertomhttps://ceilinganddryliningsupplies.co.uk/products/0130000000844
or get galv sheet sliced up.

How are these flat straps fixed to the boards, straps presumably placed on the underside of the boards (????) and perhaps fixed from the top with self tapping screws (like plasterboard with metal studs) or what ?

18mm Floorboard options

Peter_in_Hungary — Sat, 24 Aug 2024 10:26:41 +0100

Posted By: VictorianecoThe Sterling technical data doesn't seem to suggest this, but it does say:
The following general fixing
instructions should be noted:
.............
• All short edges must be supported on joists/studs or noggins.

Yes - stagger the short ends and glue the joints
but I have never put noggins under the short ends and I haven't had any problems with that.

I have always use screws, never nails.

18mm Floorboard options

Victorianeco — Sat, 24 Aug 2024 10:34:32 +0100

Perfect, thanks gents

While the floor is up, should I parge coat the outer wall ( where now exposed) or will the cavity bead take care of any potential air leakage?

18mm Floorboard options

fostertom — Sat, 24 Aug 2024 21:25:19 +0100

Posted By: Peter_in_HungaryHow are these flat straps fixed to the boards

Plonked in place across the joists, couple of screws to hold in place, boards laid fixed as normal to the joists, the straight joints central on the flatstraps, edges gapfilled glued. PK (self tapping) screws thro the boards 25 in from the butt joint, at close c/cs, pulling the flatstrap tight up to the boards' underside. The flatstrap doesn't support the boards, just connects one to the next, like T&G does.

Even better, apply gapfilling glue to the top of the flatstrap as well, before dropping the boards onto them, provided you can pull the PK screws tight while the glue is still 'open'. That's what we do when similarly fixing straight-edge 11OSB3 or 12 ply to studs/rafter soffits as sheathing that forms the airtight layer.

18mm Floorboard options

wookey — Sat, 24 Aug 2024 22:05:45 +0100

Posted By: VictorianecoPerfect, thanks gents

While the floor is up, should I parge coat the outer wall ( where now exposed) or will the cavity bead take care of any potential air leakage?

Parge it, (or seal plasterboard pieces in). Cavity beads don't make things airtight. And in my experience there are a lot of holes in the bit betwixt ceiling and floorboards, including missing bricks, and big gaps around joists.
e.g. http://wookware.org/house/retrofit/pics/html/114-joist-air-gap.jpeg.html
or at the very least small gaps because they have shrunk a bit.

So some taping: http://wookware.org/house/retrofit/pics/html/117-kitchenjoist-after.jpeg.html
or Tony-style plasterboard+tape: http://wookware.org/house/retrofit/pics/html/115-joist-taping.jpeg.html
is in order.