Flooring, T&G or splines?

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Forum topic by jeth posted 12-26-2011 03:30 PM 3945 views 0 times favorited 15 replies Add to Favorites Watch
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258 posts in 2801 days

12-26-2011 03:30 PM

Topic tags/keywords: question milling flooring

Morning all, hopefully folks here with some experience of flooring can answer a couple of questions.

I have to do some solid wood flooring, prefabbed is not an option as it all has to come out of available rough lumber. I don’t have a particularly good/heavy/stable router table set up.
It seems to me that the easiest way to “tongue & groove” the boards would be to cut grooves both edges and use splines in place of the tongue.
Any reason why not? If splines make sense then solid wood or ply, glued or floating? Ends will be butted, only edges need “joining”...

I would appreciate any suggestions :)

15 replies so far

View Dennisgrosen's profile


10880 posts in 3079 days

#1 posted 12-26-2011 03:51 PM

how many squaremeters are you talking about or better yet how many meters of board
do you think you need to make tongue and groove on
if its only a few squaremeters I wuold do it with a T & G plane or a stanley 45 , 50 , 55 or
simular planes from other factorybrands since you will have matching wood in the tongue
when they dry and swell you will be able to see the tongue partly some times in a year
I wuold allso make it at the end of the boards too …. maybee alot more difficult to build the floor
with it but will help the ends to stay flat with each other
the people I know that have used the spline metode has made it so it looks like a boatdeck
with contrasting sealing in a groove between the boards

I´ll bett when the proffessionells wake up after the festivitas they come up with alot better
answer /explanation of why you shuold do what and when you shuold do it

good luck with your floor

View jeth's profile


258 posts in 2801 days

#2 posted 12-26-2011 04:05 PM

Thanks Dennis, I don’t have a moulding or rabbeting plane of any description, and tbh i wouldn’t want to run moulding for 54 m2 of 3.5” boards by hand :)

Good point regarding the visibility of the tongue or spline, though the existing floor, which I am only replacing about half of, is pretty rough. The choice of butted ends is based on this fact, that’s how the existing floor was done and don’t want to complicate things. I could use splines made of the same wood anyway, just seems a whole lot easier to groove it all than to produce a decent male/female joint.

Enjoy the rest of your holidays, if you have them and thanks again :)

View casual1carpenter's profile


354 posts in 2439 days

#3 posted 12-26-2011 04:05 PM

jeth, Sorry this is not a real answer, mostly a few questions. This available rough lumber, is it holding at the right moisture content throughout it’s entire thickness? What is the final thickness of the flooring? How are you going to attach the flooring to the joists?

Lumber normalized to the conditions where it will spend the rest of it’s days is more dimensionally stable I believe. Additionally one would think that the plywood is dimensionally stable so, wood seasonal changes and changes as the rough cut acclimates to it’s environment could loosen or tighten the joint. Probably not an issue if the lumber was properly dried. I have seen arguments for using plywood splines in that the plywood has grain direction support across both the width and length of spline so as to virtually eliminate the chance of grain splitting and joint failure if one sees any uplift forces from pieces as they try to warp a bit.

Thickness is a determining factor in spline or T&G dimensions.

With T&G attachment can be made by nailing into the groove driving the pieces together. Me thinks the spline situation would require visible nailing toward both edges along the width.

I’m not a pro or accomplished woodworker, just a novice. Good luck with your project jeth, and remember prefabbed flooring has issues too.

View jeth's profile


258 posts in 2801 days

#4 posted 12-26-2011 04:39 PM

Thanks Casual, final thickness is about 13/16”, I mentioned gluing the splines with that thought in mind, if the spline is fixed it would be possible to pin nail through the splines during assembly, like a normal T&G. As mentioned, the existing floor is rather rough, uneven and with visible nailing so that would be acceptable if necessary, and I think I can do a neater job on it at least.

The wood is properly (air) dried, and the useful thing here is that due to the tropical climate there is rarely much difference between interior and outside conditions.

View jeth's profile


258 posts in 2801 days

#5 posted 12-26-2011 05:46 PM

Anyone else with any thoughts(bump :)???

View Jacob Lucas's profile

Jacob Lucas

100 posts in 2395 days

#6 posted 12-26-2011 06:00 PM

I had to make an aromatic cedar floor one time, I layed 1/2 inch plywood as a sub floor glued and screwed to the concrete pad. On the floor planks I tongue and grooved the edges and the ends, if you make them all the same way (ie: all tongues on the right side and the back side of the board, and all grooves on the left and front of the board) it will be a really easy process of just snapping them all together. Personally I wouldnt lay the floor unless I had the ends T&G’ed, you really dont want the ends to start to bow up on you. Professional wood floor installers will tell you that you shouldnt glue the floor to the sub floor but I couldnt find a reason not to, so I did and Ive seen no changes in the floor since I made it. Its been through about 3 seasons so far.

View TCCcabinetmaker's profile


932 posts in 2318 days

#7 posted 12-26-2011 06:11 PM

Tounge and Groove, if you’re gonna do it, you might as well do it right.

You don’t glue the tounges as they need to be able to expand and contract with teh seasons.

Also make sure when you are running your flooring, to look at the end of the boards you want your top side to be the crown side of the grain.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

View reggiek's profile


2240 posts in 3233 days

#8 posted 12-26-2011 06:58 PM

T & G is the way to go. If you don’t have a decent router, but have a good TS you can do it there. A simple jig will suffice.

If not…you can make a bench top router table fairly easy or they sell some fairly inexpensive ones that would do the trick. Personally, I would go the router route (though I have done it on a TS) it is easier to set up (make a couple of setup blocks from scrap so that you can quickly set up each bit as you change over for the tongue or for the groove (You can use the single bits (they have both profiles on the same bit)...but they require bit raising and lowering – which is more of an issue on a table without a lift).

Also, I would not recommend that you ever try to free hand router this profile – Though I have seen a jig made to do it this way.

Lastly, I would recommend you do not glue T&G to anything….except for the edges (finish nailing is preferred here though – or a decorative edge cap).

If all else fails – you can cut half laps on the TS and use deck screws – or even try the kreg hidden deck screw jig. Floating splines would be a very difficult task – if you do not get them perfect – your floor would get loose and have a tendency to trap dirt and debris in the slots….

-- Woodworking.....My small slice of heaven!

View jeth's profile


258 posts in 2801 days

#9 posted 12-27-2011 04:59 AM

Thanks for the further replies folks.

TCC, sorry if I wasn’t clear, I meant gluing the splines into the groove on one side of every board to create the tongue, rathert than gluing the boards down or together.

Unfortunately I don’t have a decent table saw easier, I do have a router and a basic table, but the router is old and likes to readjust itself which doesn’t help for these kind of tasks, and the table itself is, as I say, basic, and not especially great for precision work, normally I set it up if I have to run a lot of chamfers, roundovers etc

To be honest after checking out the material it might be convenient to go with splines, it means I can make the boards a a little narrower and reduce waste a lot considering the dimensions of the slabs. I honestly can’t see a huge difference between a “real” tongue & groove machined into the edge or a groove with a glued in tongue, but then, if I was sure of that, i wouldn’t have been asking the question :)

View TCCcabinetmaker's profile


932 posts in 2318 days

#10 posted 12-27-2011 05:52 AM

no, you’ll get squeeze out which will go into the next board, and won’t allow for movement.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

View jeth's profile


258 posts in 2801 days

#11 posted 12-27-2011 06:00 AM

was thinking to stick them prior to install, not during..

View TCCcabinetmaker's profile


932 posts in 2318 days

#12 posted 12-27-2011 06:09 AM

Then you are liable to still get glue squeeze out, except it will keep your tounges from going into the grooves properly.

It seems easier, but honestly it just adds more things that can possibly go wrong. Not to mention if you use a different material to make the tounges, it can expand and contract differently effectively busting your groove that you put the spline in.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

View BentheViking's profile


1782 posts in 2527 days

#13 posted 12-28-2011 04:45 AM

do all of your T&G on a table saw. take some work to set everything up right, but once you have things dialed in you may be able to just run with it…just make sure you give room for expansion and contraction in your joints

-- It's made of wood. Real sturdy.--Chubbs Peterson

View HerbC's profile


1740 posts in 2823 days

#14 posted 12-28-2011 04:57 AM


Jeth says he doesn’t have a decent table saw.

And since his router is in bad condition, I don’t know how he’s going to make either T&G or splines…


-- Herb, Florida - Here's why I close most messages with "Be Careful!"

View jeth's profile


258 posts in 2801 days

#15 posted 12-29-2011 04:52 AM

Hi Herb.. splines, bandsaw, planer, grooves, set my little craftsman saw up the best I can and have at it ;) Probably the best option in the light of my set up, will use same wood as the boards. I have checked the existing floor and it’s the same so that’s a good enough excuse for me to keep things simple. I ask top learn but at the end of the day down here the reality is not always perfect, it’s making do with what you got and what you can do. Also expectations are lower, and I am sure the floor will look and last better than what is being replaced.

Thanks for all answers anyways folks, always interesting to know how those with “perfect” shops get things done :)

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