# Reducing waste on tongue and groove 22mm chipboard flooring options?



## Rob Cheetham (22 Jan 2022)

I have just finshed laying my dpm and 50mm celotex board down on the concrete base floor and am now ready to lay the 22mm t&g chipboard. The space comes out at 16.2m2 and each board is 1.44m2. So in reality plus 10% should be 12..37 boards. I have bought 12 but im still feeling that I will need more if im not too lose the tongue or groove on some off my areas where I have to do cuts. 

I have gone on my sketchup design and found that I will get 10 full boards down with staggered joints. Then be left with two 9cm full length strips, 5 other 38x60cm gaps and one 38x9cm gap

My question is once I have cut the boards down that give me the tongue and the groove in tact still then for the rest I was thinking cutting a 45 degree angle on both joins to act as the joint and then to make sure they glue tight I will put temperary wedges in the expansion gaps to make sure it they push it up tight and creates a tight strong joint.

Would this work or am I going to have to go out buy extra boards just so I have got the tongue and the groove,

I have a router table but I have heard that to get a cutter to cut the exact t&g profile would probably mean getting one speicially made. So that is out of the question.

Any advice would be greatly appreciated. Thanks


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## Jameshow (22 Jan 2022)

Biscuit joiner???


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## Jones (22 Jan 2022)

Use the offcut ( minimum 300mm) to start the next run. If you don't have enough buy more it's not expensive.


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## baldkev (23 Jan 2022)

If you value your time into the equation, its cheaper to buy an extra sheet or 2 and you wont need to worry about the joints


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## Rob Cheetham (23 Jan 2022)

Jameshow said:


> Biscuit joiner???


Havent got one unfortunately but its on my wish list for the future lol. Thanks for the response


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## Rob Cheetham (23 Jan 2022)

Jones said:


> Use the offcut ( minimum 300mm) to start the next run. If you don't have enough buy more it's not expensive.


Think I will just buy extra like you say. You say minimum 300mm off cut is that width or length as I have two full length strips at the end that are only 90mm wide. Thanks


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## Rob Cheetham (23 Jan 2022)

baldkev said:


> If you value your time into the equation, its cheaper to buy an extra sheet or 2 and you wont need to worry about the joints


Think your rite lol. Any good ideas for a use of a load of chipboard flooring offcuts after though would be much appreciated. I hate wastage lol


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## Rob Cheetham (23 Jan 2022)

This is what I am left with offcut wise. I have 12 boards at 600mm x 2400. Thinnk 2 more boards would be enough or 3?


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## TomGW (23 Jan 2022)

Make sure you leave an expansion gap all the way around the room, to be covered by the skirting. 
At the edge of the room, if you’re going to have a narrow gap, just trim the tongue/groove off the last full board to create a square edge and butt join a strip, glued with wood glue. On 22mm chipboard it will be 100% ok. I did it 35 years ago on a 18mm floating floor on white polystyrene and no issues. Celotex is much more supportive and 22mm is a greater surface area so I would have no concerns whatsoever.


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## eribaMotters (23 Jan 2022)

What happens if you run the boards across the room width as opposed to along the room length?

Colin


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## Rob Cheetham (23 Jan 2022)

TomGW said:


> Make sure you leave an expansion gap all the way around the room, to be covered by the skirting.
> At the edge of the room, if you’re going to have a narrow gap, just trim the tongue/groove off the last full board to create a square edge and butt join a strip, glued with wood glue. On 22mm chipboard it will be 100% ok. I did it 35 years ago on a 18mm floating floor on white polystyrene and no issues. Celotex is much more supportive and 22mm is a greater surface area so I would have no concerns whatsoever.


So your saying for the offcuts that I dont have any tongue or groove edges left to just butt join them together and they will be ok? Obviously with the wedges in between the expansion gap (which I have included) pushing the joint up tight to make a secure tight bond.


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## MikeH (23 Jan 2022)

Rob,
Are you sure that the 2400mm, and the 600mm, measurements don't already include the tongue. i.e. make sure that the useable floor area is what you are actually getting and isn't actually something like 2380mm x 580mm per board and the tongues make it up to 2400 x 600. I have been looking at the same sort of stuff for a project but it doesn't seem to mention if the dimensions are with or without the tongue.


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## Rob Cheetham (23 Jan 2022)

MikeH said:


> Rob,
> Are you sure that the 2400mm, and the 600mm, measurements don't already include the tongue. i.e. make sure that the useable floor area is what you are actually getting and isn't actually something like 2380mm x 580mm per board and the tongues make it up to 2400 x 600. I have been looking at the same sort of stuff for a project but it doesn't seem to mention if the dimensions are with or without the tongue.


Just checked for you @MikeH and the dimensions are actual useable floor area so with tongues on top they are actually slightly bigger than 2400 x 600


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## Rob Cheetham (23 Jan 2022)

@eribaMotters this is what I get going the other way. So 8 full boards. Will use a 9th to get the shorter width of the full length. Three more boards would cover 6 of the 9 left over spcaes. if I buy one more can then sort up to 8 ofcut spaces then for the 9th think ill just use whats left to butt joint up in a place that wont have any traffic like a bench corner mayby etc. Think this way will be better than the other so thanks.

Still though let me know what you think?


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## Jameshow (23 Jan 2022)

I would plank it running... 

So the end of one board becomes the start of the next line of flooring. Saves on boarding and means joints are random.... 

Might not suit OCD Types!


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## TomGW (23 Jan 2022)

Rob Cheetham said:


> So your saying for the offcuts that I dont have any tongue or groove edges left to just butt join them together and they will be ok? Obviously with the wedges in between the expansion gap (which I have included) pushing the joint up tight to make a secure tight bond.



Yes, butt join two square edges with glue and wedge for 24 hours. 
Ours is 18mm with the edges of most rooms like this and no movement at all. Actually, the living room has a strip of 6 or 8 inches along one side and a piano has sat there for over 30 years, with the rear feet on the strip and front feet on the full sheet and no movement at all. Try a test piece - glue it up, wait a few days, set it on Celotex and see if you can break the joint with a sledge hammer. 
I don’t know what you’re thinking of for doorways. When I did this there was no internet and I’d never known of anyone to do it before. I cut a series of pieces, maybe seven to span the gap, less 1/4” and glued them alternatively to each room, a bit like an interlocking comb. This allows expansion movement. Again it has worked without any issue.


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## Distinterior (23 Jan 2022)

Jameshow said:


> I would plank it running...
> 
> So the end of one board becomes the start of the next line of flooring. Saves on boarding and means joints are random....
> 
> Might not suit OCD Types!



So would I and have done so on many occasions.
My workshop floor is done like this and has many heavy machines sitting on it without issue.


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## peterw3035 (23 Jan 2022)

Same here, random joints are fine and they will be less obvious than your first layout. I used one of the 5 minute type adhesives, draw the joints up tight and it works far better than working on top of the new floor and avoids the risk of boards moving & joints opening up.


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## Jones (23 Jan 2022)

Use random joints. Lay a full board then cut a piece to fill the gap leaving 10 mm min expansion gap to perimeter. The next row starts with the offcut and you carry on like that. Start with the tounge facing out and a tounge to the end then it's easy to drop in the last board. Run a fat bead of pva on the tounge before pushing the boards together. I've never felt the need to wedge , but do put spacers behind first run to keep it off the wall ,remove after glueing to allow expansion gap to work. Usually length 300mm width 150mm minimum piece. If you're butt jointing boards then something went wrong with the cutting, you should always have a tounge on the offcut ready to push the next board on to.


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## Molynoox (26 Jan 2022)

I encountered this exact same problem with my build - it had a small sliver at the front edge maybe 150mm, 4 boards wide, all along the front. I wanted to just use one board for the 4 length width.
I looked at getting router bits to put the grooves back into offcut boards but gave up looking in the end and just bought 4 extra boards. Seems wasteful but seems like the only way
Martin


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## Rob Cheetham (30 Jan 2022)

Molynoox said:


> I encountered this exact same problem with my build - it had a small sliver at the front edge maybe 150mm, 4 boards wide, all along the front. I wanted to just use one board for the 4 length width.
> I looked at getting router bits to put the grooves back into offcut boards but gave up looking in the end and just bought 4 extra boards. Seems wasteful but seems like the only way
> Martin


For my last three full boards with three cut pieces at the ends I ended up just cutting each end at 90 and gluing up with a buttt joint and leaving wedged tight for 24 hours. Seems to be solid for me now and im putting 7mm pvc interlocking tiles down on top so should be ok. If there is any movement in them spots in the future I will lift tiles inspect and if they have come loose I will count my losses and remove the butted boards and replace with new t&g boards. Still had the top edge with the tongue into the groove so should stay put.


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## Molynoox (30 Jan 2022)

I'm guessing your joints fall on a joist in that case. Mine don't.
Martin


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## Rob Cheetham (1 Feb 2022)

Molynoox said:


> I'm guessing your joints fall on a joist in that case. Mine don't.
> Martin


In your case I agree with you. I would just buy the extra boards but mine is a floating floor consisting of dpm - 100mm concrete base - dpm - 50mm celotex - vapour barrier - 22mm chipboard t&g - 7mm pvc interlocking floor tiles so luckily no joists to have to sit joints on


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## Molynoox (1 Feb 2022)

Ah yeah, so in that case you don't even need to think about it the joists. Glued butt joints the winner for that application

Martin


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