Thread: T&G flooring / lining boards, one router table or two?

You could do the groove with a hand held router, and the tongue/s with the table router, if you need to do them a few at a time?
If all in one go, I'd be doing the changeover in the table.

I am thinking about batches of about 20 at a time, run a batch, fix them off, run another batch and so on. That way, if (or, in reality, when) I make a stuff-up I will only have that batch of boards to turn into kindling. If I do the router change-over in the table I should be able to minimise the problems associated with setting the cutters to match. The next question is if there is a better (easier?) method of getting a neat join on lining boards?

several things come to mind.

1. keeping the boards flat to the router table can be a challenge

2. do you really need tongue and groove boards? Would a ship-lap join work for you?

3. lining boards often incorporate a bead where they join to "conceal" movement at the join.


in terms of set-up, you could cut a set of master templates from UHMW plastic that you use to reset the bit height each time you need to create the set-up.

I've run off lots of both flooring & lining on a router table. Three houses worth to date. From timber I'd felled, cut, dried, cured & dressed myself: Tas Myrtle (Nothofagus cunninghamii), Wattle (Acacia dealbarta), Tas Oak (Euc. obliqua), Blackwood (A. melanoxylon) & English Elm (Ulmus procera).

All done with (initially) an Alaskan mill (horrible) & later a Lucas Mill, basic Elu saw bench, Kity under & over & a Triton Mk III with an Elu 177 router mounted. The floors & linings are just lovely, esp. the Wattle & Myrtle. A slow but extremely cost effective process.

Just a couple of do & don't suggestions. The planks need to be more or less uniform (obviously). This is not easy with this process, as butt-jointed boards need to be virtually micrometer perfect & ever so slightly undercut to look best. I always used a "centred" staggered edge fixed "Glue Joint" bit for flooring, inverting each plank's alternate sides for continuity of mating edges. This was the most economical use of timber, as the grooves were a mee 3mm or so deep on each side of the boards. Much less wastage than conventional "stacked" T&G arrays. It allowed just enough overlap for carefully applied but invisible secret nailing.

I also broke every safety rule in the book by sandwiching the inverted plank between the fence & a totally unguarded rotating bit for the second cut to allow for totally parallel sides & uniform width. This is highly dangerous, as there's no guarding around the naked bit, no effective dust extraction and I really can't recommend this course of action to anybody else. It might be effective (there's no real viable alternative if you need close butt joints & parallel plank sides) but also extremely irresponsible and dangerous too. You've been warned! Paired push-sticks & hold-downs are all but mandatory if you're stupid enough to attempt this! A "tailer-out" or at the very least a roller stand at the outfeed is also highly recommended.

For the linings I used much thinner (10mm) blanks with a "Stacked" 3-wing V/J Cutter array, with the centre of the stack interchanged between a groover & a plain washer of the same thickness. Obviously the boards are fed the same way up for each alternate side.

You need to estimate your board coverages accurately, and ensure the planks are correctly acclimated to their site if you're using the same shallow flooring edge profile as I have. To ensure uniformity & compatibility all boards need to be run as one: first one side, then the other. This prevents squeaks or other undue movement, and don't spare the pressure when laying them either: quality flooring clamps (Record) or paired slender wedges on alternate joists work equally well for flooring. Linings are much more forgiving, of course. Often just some gentle encouragement with a rawhide hammer is all that's required for alignment & butt joints.

Ian, I was going to set up a bench long enough to support a 2.4M board while it was being processed. Shiplap would be fine, as would be a 45 degree bevel on the edges of the boards. I did this with some reclaimed bamboo flooring I was given after it's owners got sick of it developing humps and hollows when the weather changed from dry to damp. It looked good but was a real pain to cut and the splinters........ Oh dear, those splinters!
"Ratbag", I am planning on using North Coast Ironbark for the boards, cut on a "baby" Lucas mill and thicknessed and edged on a planer/thicknesser. I plan to run the boards vertically so there need be no end joins and if the widths are slightly random it won't matter. I was planning to use Ironbark for decking boards but there seems to be some concern that the location of the building might mean that hardwood decking is too much of a bushfire hazard and something totally non-flammable might be needed.
Thinking back to shiplap, would it be an idea ti fir an extra "noggin" to the wall frame to help with keeping the boards in line? 1.2M is a long span for a shiplap join but 800mm would give better control over bowing and twisting.

vertical lining boards might behave better if fixed on 450 centers.
If fixing over OSB (which I think is the current norm for thin, 10 mm, lining boards) is too costly, perhaps you could use 25 x 35 battens

25x35 battens on a wall with just 1 stud? I never thought much of that OSB board stuff, I have my doubts about nails holding in it but as a draft barrier it would be OK. I was going to use 19mm boards but if I come back to 12 or 15mm I would save some timber and the router would do less work so thank you for the suggestion.

The battens would only be spanning between studs -- which are at 450 (or is it 600?) centers.

In Canada, OSB is very common and no one appears to have any issues with its ability to hold nails.

Must be different stuff to what I am thinking of, will have to consult Dr. Google for more info.