Lifting flooring

[spiidey]

Have decided to have a bit of a rethink on this, as we're not keen on getting the joist hangers/noggins all correct down the full strip of flooring at the side to give us enough piece of mind.

So, we've thought of a potential other workaround, and would appreciate guidance on feasibility.

Looking at the picture below, the room with the flooring up is obviously on the left, with an internal partition, then one of our other upstairs rooms on the right.

What we would intend doing is the following:-


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1. Take off the skirting on the LEFT AND RIGHT hand sides of the internal partition;

2. Knock out the plasterboard on the RIGHT side of the partition up to a height of approx 40cm from the floor. Note we can't knock the plasterboard out on the LEFT hand room as the missus has wallpaper on the wall and she can't find the same and doesn't want to change it)

3. This would allow us access to the joist that sits directly underneath the partition (along with access for our power tools to get at the existing flooring/screw the new flooring down).

4. Cut the existing floorboard panels that remain in the room on the left (see bottom pic which shows how much of the flooring remains "sticking out"), to the MIDDLE of the joist that sits underneath the partition, using a circular saw (joists 65mm wide). We'd access this from the knocked out plasterboard hole in the right hand room. We'd obviously have to cut around the vertical timber trusses that will be in the partition.

5. Lay the T&G floorboards in the room on the left, starting at the internal partition, sliding the first of each row of floorboards underneath the plasterboard on that side of the partition, so that the end of each panel rests on the joist that sits underneath the partition, and flush with the edge of the existing floorboard panel that floors the room on the right.

6. Stick the skirting back on the left hand room.

7. Resheet the bottom of the plasterboard wall, and stick the skirting back on, in the right hand room.


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Will this work or is there anything obvious that we've missed / simply won't work?

Maybe seems like a bit more work (I'm not 100% sure it is but seems that way), but it prevents us playing around with joist hangers / noggins when we're just not confident enough to do so, and patching back the plasterboard is a simply enough task.

 

[spiidey]

A few other queries.

A. Our joists are at 400mm centres (or thereabouts as having laid the rockwool between them they ain't bloody parallel with each other!!). Each joist is 65mm wide. We need 22mm thick T&G flooring to get same height as existing. Is there any specific sized sheets of T&G flooring that would work best for this layout? Total room is 4.6m wide (i.e. at right angles to joists) by 3m long (the joist direction).

B. Is there any specific type of T&G flooring we should get - e.g. P5 graded for moisture resistance? Any other considerations?

C. On the joist at the very left hand side of the room, the handyman we had in cut the flooring back so that 20mm of the joist was exposed i.e. 20mm of the new flooring can be laid directly over the joist. How far over the joist do the ends of each panel need to be - is 20mm enough, what is the minimum?

D. Is there a power tool that can cut the flooring so its flush with the edges of the skirting around the remainder of the room i.e. doesn't leave a gap of 30-50mm like the bloody handyman left?

 

[spiidey]

Ok, have taken the skirtings off and we actually have quite a bit to play with.

IF we were able to cut along the red line as shown in the pic below, we'd be able to get the edges of each floorboard in the room to sit on at least 20mm of the joist underneath.

Is there a power tool that will allow us to cut the floorboards along the red line? Floorboards are 22mm thick.

LINK TO ORIGINAL FULL SIZE IMAGE:- http://tinypic.com/view.php?pic=xgcq69&s=8#.VRw39OHkrRk

 

[Deleted member 174758]

We need 22mm thick T&G flooring to get same height as existing. Is there any specific sized sheets of T&G flooring that would work best for this layout?

Pretty much all of it is 2400 x 600. If your end joints don't land on a joist you'll need to fix a batten beneath that joint. I always PVA glue (Exterior D3 or D4 PVA) my tongues and screw at 150 or 200mm centres on the joist which seems to work well (i.e. they don't squeak). Always go for green (P5) if you can

C. On the joist at the very left hand side of the room, the handyman we had in cut the flooring back so that 20mm of the joist was exposed i.e. 20mm of the new flooring can be laid directly over the joist. How far over the joist do the ends of each panel need to be - is 20mm enough, what is the minimum?

Just about, providing thayt you angle the screws and re-pilot/countersink before screwing on

D. Is there a power tool that can cut the flooring so its flush with the edges of the skirting around the remainder of the room i.e. doesn't leave a gap of 30-50mm like the bloody handyman left?

Two that I can think of - a jamb saw (specialised flooring tool - it would be a hire job as they are VERY expensive) or a multitool (although it's going to be a long, noisy task with one of them (as well as potentially using lots of blades). TBH I'd consider having a go with a 1st fix hand saw, wide chisel (1-1/2in) and a hammer. The joint doesn't need to be perfect, after all

BTW the issue of noggins is probably a non-issue for a joiner - all I'd do would be to cut and nail noggins between the joists (90mm ring annulars). With a gun the first end is skew nailed, the second is through nailed. The noggins won't really be taking that much weight, they are more there to stiffen-up the chipboard above them. No need for hangers which are overkill IMHO

 

[spiidey]

Pretty much all of it is 2400 x 600. If your end joints don't land on a joist you'll need to fix a batten beneath that joint. I always PVA glue (Exterior D3 or D4 PVA) my tongues and screw at 150 or 200mm centres on the joist which seems to work well (i.e. they don't squeak). Always go for green (P5) if you can

Thanks - yeah we were looking at the P5 sow ill go for that. What type of glue should be used on the tongues?

Just about, providing that you angle the screws and re-pilot/countersink before screwing on

Thanks, will ensure we've got at least 20mm and angle the screws + repilot/countersink before screwing on.

JTwo that I can think of - a jamb saw (specialised flooring tool - it would be a hire job as they are VERY expensive) or a multitool (although it's going to be a long, noisy task with one of them (as well as potentially using lots of blades). TBH I'd consider having a go with a 1st fix hand saw, wide chisel (1-1/2in) and a hammer. The joint doesn't need to be perfect, after all

Ok, I'm keen to try the last option unless there is a power tool that will definitely work.

So for the 1st fix hand saw, chisel and hammer, what's the process?

Try and cut some of the board with the 1st fix saw, and then once say half way try and chisel/hammer the remainder of the board off? What risk of damaging/warping/twisting the joist have I got from doing this?

Although, I've never heard of a multitool - what are these and how do they work?

 

[Deleted member 174758]

yeah we were looking at the P5 sow ill go for that. What type of glue should be used on the tongues?

I edited my response above to comment on glues and joist hangers. You need a D3 or D4 (exterior grade) PVA. Something like Bostik Resin W (blue bottle)

So for the 1st fix hand saw, chisel and hammer, what's the process?

Try and cut some of the board with the 1st fix saw, and then once say half way try and chisel/hammer the remainder of the board off? What risk of damaging/warping/twisting the joist have I got from doing this?

Use the wall to run the saw against and saw as deep as you can for a couple of feet - right up to the first joist and just above it. If you put a slight score in the top of the joist it doesn't really matter that much - just don't saw through it! Use the hammer and chisel to chop out the stuff you've already weakened by sawing. Be careful not to hit the chisel so hard that you go through the ceiling below! (maybe pop an offcut of floorboard or the like beneath the cut point). Once you've got it started you can probably saw 95% of the rest out just using the hammer and chisel above the joists to sever the last bit of the wood fibres

I've never heard of a multitool - what are these and how do they work?

Fein Multimaster FMM250Q multitool:

Untitled

• Deleted member 174758
• 18 Jun 2014
• 1

Other brands are available from £35 to £200 + blades. The sawblades (3rd from the right) oscillate through a 3 degree arc at extremely high speed

 

[spiidey]

Would this multitool work?

http://www.screwfix.com/p/energer-enb518htl-200w-multi-cutter-220-240v/61122

And are these the correct type of screws to fix the new floorboards?

http://www.diy.com/departments/bq-8...25_BQ&ef_id=VHucQAAABesrQz5K:20150401210638:s

And is this the correct type of glue?

http://www.screwfix.com/p/evo-stik-...oogleBase-_-Datafeed-_-Sealants and Adhesives

 

[Deleted member 174758]

Would this multitool work?
http://www.screwfix.com/p/energer-enb518htl-200w-multi-cutter-220-240v/61122[/QUOTE]
Don't see why not. It will go through lots of blades though (nature of the task, not the machine), With a hand saw you should still only need the multitool to start the cut and maybe for the bits over the joists - for the rest a 1st fix hand saw will be much faster

And are these the correct type of screws to fix the new floorboards?
http://www.diy.com/departments/bq-8mm-60mm-wc-cistern-fixing-pack-of-2/254725_BQ.prd[/QUOTE]
They are cistern screws! Try Floor-Tites, like these - the unthreaded bit at the top means they pull up better than full-length thread screws

And is this the correct type of glue?
http://www.screwfix.com/p/evo-stik-wood-adhesive-interior-1ltr/37901[/QUOTE]
It will do, although that's the green interior stuff (D2). If you are using moisture resistant boards then you should surely also be using moisture resistant glue, like the blue (D3) stuff I recommended

 

[spiidey]

Thank you for all of the above - and what a school boy error on the cistern screws!

Will give it a go with a combo of the multitool and the 1st fix saw.

Once again thanks for all your help.

 

[spiidey]

http://www.toolstation.com/shop/Scr...Range/sd3339/Floor-Tite+Tri-Lock+Screw/p51501

Is it the 45mm or 55mm version of these for fitting 22mm floorboards?

 

[Deleted member 174758]

Either. 23mm into the joists should be enough, especially as you are putting them in at close centres

 

[spiidey]

Does the P5 come in different shades? Company we're buying from us saying they'll give us P5 but it's not dyed green.

 

[Deleted member 174758]

Some manufacturers add green dye to indicated that the material contains a damp-proofer, but not all (same as MR-MDF). There is no universal standard

 

[spiidey]

Some manufacturers add green dye to indicated that the material contains a damp-proofer, but not all (same as MR-MDF). There is no universal standard

So if it doesn't come with the green dye, but is labelled P5, is this still moisture resistant?

 

[Deleted member 174758]

P1 is the most ‘basic’: a general purpose board for no specific end use; whereas P2 and P3 are for furniture and interior fitments. What we commonly call ‘flooring grade chipboard’ is actually a range of types: P4, P5, P6 & P7, all described as ‘load-bearing’. Where P4 and P6 are for use in dry situations and P5 and P7 are for use in places where moisture, dampness or spillages might be an issue: especially bathrooms and kitchens, of course.

Moisture resistant boards are generally indicated by a green colouration; either throughout the board, or as a band or layer within the board’s construction. But this is purely a green dye, to make those boards easy to identify as being the ‘moisture resistant’ type.

The above is referring to standardised European grades of particle board (hence "P1", "P2", etc)