shop made T&G flooring question

[Martin Rock]

Hi all


I will be milling my own maple flooring with tongue and groove. To maximize the planks width, I plan to get a final thickness of about 5/8. My question is: Is 5/8 too thin for t&g flooring? I am afraid that the top lip of the groove will be too fragile.

thanks

Martin

[Chris Padilla]

It will only be too thin if you:

(1) cut it too thin or
(2) use commercial cutters (router/shaper bits) designed for 3/4"

This is a mountain of work for sure!

[Bobby Knourek]

You can consider doing a simple ship lap, rather than T&G.
or minimize the depth and width of the mate, and a custom adjustment may be in order.
Woodworkers Tool Works in Wi. can modify or maufacter the size you need.
But if you have close enough nailers (rafters/joists) I would suggest the ship lap cut.

Bobby.

[Peter Quinn]

Hi all


I will be milling my own maple flooring with tongue and groove. To maximize the planks width, I plan to get a final thickness of about 5/8. My question is: Is 5/8 too thin for t&g flooring? I am afraid that the top lip of the groove will be too fragile.

thanks

Martin

Hi Martin, You may be getting a bit thin on the groove side at 5/8" using a regular 3/4" cutter set. At 5/8" you already have a thinner wear layer, so keep that in mind. It might be tempting to cheat the 1/8" mostly to the bottom of the tongue on the groove side of the cut to maximize the wear layer, but this is what holds the board to the floor on one side. If this is wide plank you will be gluing down or screwing/face nailing, then it is less of a concern. Bit if its a standard application, especially with an unstable species like maple, I'd worry about lifting. So if you divide the 1/8" you have lost over both top and bottom of the groove, or center the 1/4" groove on the 5/8" board, you have 3/16" left of wear layer. Basically you have eliminated one or two sanding opportunities over the life of the floor. This may be an acceptable situation to get the widths you are after or not depending on your goals.

We have flooring sets at work for thinner floors generally meant to go over an existing floor or in other special elevation situations. They produce flooring as thin as 7/16", and the tongues are thinner rather than weaken the groove side more than is necessary. I am not sure what brand they are, but you could certainly get either HSS or carbide backed corrugated knives ground if the volume warrants a custom geometry but custom brazed tooling is too expensive. I'm not sure how you could have stock brazed tooling modified toe reduce the tongue thickness as part of the equation as that would involve ADDING material to the cutter, not subtracting, but changing tongue thickness is really the best approach IMO if the thinner wear layer is unacceptable to you.

[Martin Rock]

Peter, I have a basic adjustable T&G cutter for routers, so I can have my tongue the thickness I want.

My planks are flitch sawn hard maple (mostly QS and rift sawn boards). they were ripped at the pith or mid board to maximize stability. the planks width is from 4" to 7". I plan on gluing the boards over 6" only.

My plan is to have the plank thickness to about 21/32 (1/32 over 5/8) the tongue and both groove lips will be 7/32. The reason I want the same thickness over and below the tongue, is that is will permit me to select the plank face on installation and also simplify the milling. And also, like you mentionned I don`t want to have the bottom lip too fragile.

Martin

[Peter Quinn]

So no relief cuts on the bottom face?

[Martin Rock]

well, I don`t know about the relief cuts, does it really help reducing the cupping or crowning?

if so, I may do these cuts on board over 5" that are not Quarted Sawn.

Martin

[hank dekeyser]

You didn't say how many sq ft of flooring you will be making ? Just curious -

[Peter Quinn]

I don't really know iif the reliefs reduce cupping, I know wide planks still cup even with them. At work we make up to 20" wide planks and they sure will cup a bit. But they do seem to lay down better with reliefs, and it gives the extra glue a place to go on instalation. I think most of these wide floors get set in an elastic mastic to keep them flat over time. More of a concern is the geometry at the edges which form a back bevel that forces the edges into allignment at the faces. I have not seen flooring that was milled reversible for this reason, though the wall paneling is often milled with a different V on each face. I have also seen a local outfit that makes rustic floor where they simply nail and glue wide plank oak barn boards down with no t&g, butt edges and cut nails through the face. These are striking handsome floors and they seem to work fine though there is a lot of sanding involved and the aesthetic is very different.

[Martin Rock]

I have about 600sq feet to do, all with basic shop tool: jointer, planer, table saw and router table. Indeeed a mountain of work!

Peter, you brougth a good point: the bevel on the edges for aligment and for ease of installation. I need to give it a tought.

As for the glue, any recommendation? I have heard that PL Premium does allow for wood movement.

Martin

[Philip Johnson]

One concern I would have is keeping the edges perfectly straight so the joints fit tight and the other is cutting the tongue and groove on a router table. If your boards have any bow the groove will not follow the edge you really need a shaper with a power feed to keep the board flat on the table or your tongue and grooves will not line up good. You may have better luck using the router out of the table so it follows the bow in the boards. I would try a few and see how the fit is before I mill it all.

Phil

[Brad Shipton]

This is about 45hrs of labor rough to ready to install with the equipment you have. Then comes the install, sanding and finish. I have made about 1,000sqft thus far. Not one of my best decisions during my reno, but once pride kicked in, I was stuck with it.

I cannot quite follow the reason why the 5/8" thickness allows you to maximize your plank width? If you are starting from 4/4 stock, I can't see how your yield will change from 5/8" to 3/4". Some manuf. offer 5/8" solid, but I must admit I have never looked closely to see if the profiles are modified. I would stick to 3/4" unless there is some other flooring you are matching. One bonus of doing so is that if you need any transitions, misc. stair parts, or hardwood registers, they are easy to find. Trust me, you will be sick of this job by the time it is done.

I suggest you use either the Sika or Bostick Best flooring adhesives. They are a polyurethane meant for exactly what you are doing. They are rated for solid planks up to 8" wide. Keep in mind if you ever want to remove this finished floor, the subfloor will come up too. It is also very messy to work with.

What is the max. plank width you are planning? If your home does not have a humidifier to minimize moisture swings I would be very careful about this decision. I made some 10" wide planks on my last batch and when the season shifted from summer to winter I have three planks where there are gaps almost 1/16" wide. I was fairly careful during my milling, but there were a few nice boards that I fought with at ever go, and wouldn't you know it, these are the ones. The gaps bug me. The max gap in my rooms with 5" flooring is less than 1/32", and that I can live with. Nobody but me notices these.

Brad

[Martin Rock]

thanks for the tip Philip

I will make sure to keep the boards flat on the table top.

I will mill the t&G in place prior to installation, so I will only mill a few boards at a time, then install them. It is a slow process but I am in no hurry, and if something goes wrong or gets out of alignment, I will notice it soon enough.

Martin

[Martin Rock]

Brad

My board are from 4" to 7" wide and 4 to 9 feet long. I will loose lots of wood while jointing and planing. I don't think I will be able to get 3/4 thick without further crosscutting or ripping the boards to smaller length or width.

If the boards were shorter and narrower then 3/4 would be doable

thanks for the comments

Martin

[Brad Shipton]

I take it your stock is not starting as 4/4 rough then? 4/4 will yield 3/4" quite easily.

Brad