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

[Rob Cheetham]

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

 

[Jameshow]

Biscuit joiner???

 

[Jones]

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

 

[baldkev]

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

 

[Rob Cheetham]

Biscuit joiner???

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

 

[Rob Cheetham]

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

 

[Rob Cheetham]

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

 

[Rob Cheetham]

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?

 

[TomGW]

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.

 

[eribaMotters]

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

Colin

 

[Rob Cheetham]

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.

 

[MikeH]

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.

 

[Rob Cheetham]

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

 

[Rob Cheetham]

@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?

 

[Jameshow]

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!

 

[TomGW]

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.

 

[Distinterior]

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.

 

[peterw3035]

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.

 

[Jones]

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.

 

[Molynoox]

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