Breaking open a toungue and groove overlay floor for underfloor access

[cf-leeds]

My worst nughtmare has come true. I have a leak in a cold water pipe which is under the floor of the loft room.

Assuming i get the leak location right, I will have to rip open the ceiling below the pipe, to repair it, then patch up the ceiling again afterwards. It's an overboarded lath ceiling, so that should be fun.

If I can't get to the pipe in that way, I will have to break open the Oak T &G plank floor that I laid in the loft room, in order to get to the pipe. A s you can guess, the problem is in the middle of the room, 1 m from the edg e.

I used tongue-tight screws to lay this plank floor, as it's on top of chipb oard. I was thinking of sacrificing one of the planks near the problem area and t hen removing a small area of planks. I figured that I could then maybe re-l ay the removed plank area and on the final plank, remove half of the groove and the end tongue, in order to screw it down from above, then fill over t he screw heads.

Well, it's either that, or completely remove the half the entire floor + sk irting etc.

Has anyone done such a "surgical removal" of a plank area and can you give me any tips, e.g. how the break into the first plank - what would be the be st type of saw to use ?

Or, would you just tell me to bite the bullet and rip up the floow from one end. Just the thought of that spoils my day....

Cheers

cf

[Nick]

Assuming i get the leak location right, I will have to rip open the ceiling below the pipe, to repair it, then patch up the ceiling again afterwards. It's an overboarded lath ceiling, so that should be fun.

If I can't get to the pipe in that way, I will have to break open the Oak T&G plank floor that I laid in the loft room, in order to get to the pipe. As you can guess, the problem is in the middle of the room, 1 m from the edge.

I used tongue-tight screws to lay this plank floor, as it's on top of chipboard. I was thinking of sacrificing one of the planks near the problem area and then removing a small area of planks. I figured that I could then maybe re-lay the removed plank area and on the final plank, remove half of the groove and the end tongue, in order to screw it down from above, then fill over the screw heads.

Well, it's either that, or completely remove the half the entire floor + skirting etc.

Has anyone done such a "surgical removal" of a plank area and can you give me any tips, e.g. how the break into the first plank - what would be the best type of saw to use ?

Or, would you just tell me to bite the bullet and rip up the floow from one end. Just the thought of that spoils my day....

Could you crosscut the required boards and then cut the tongue(s) with something like a universal saw? Then prise the board out somehow. Nice thin kerf and *might* cut through screws. Similar process for the chipboard beneath. Then make good as required. All the best, Nick.

[Mike Barnes]

IME it's a mistake to assume that where you see the water emerging is directly below the location of the leak. You could end up removing a lot of boards searching from above. I'd start by cutting a small easily-patchable hole from below, for a periscope. A multimaster-type tool is ideal for this.

[cf-leeds]

That's good point - I'll do that first.

[spuorgelgoog]

I don't know whether screw placing could upset use of the tool, but the usual answer to through-floor access is a router and inlay set eg

You do end up with a visible access hole but at least it's neat and flush.

Owain

[Dave Liquorice]

A jigsaw with blade broken off such the the maximum excursion is the same or only just more than the thickness of the boards. Ease it down into the interboard joint by rotating the saw until the plat is fully down and cut along to half way across a joist. Turn saw round cut along to another joist. Similar process across the boards starting in the middle and cutting to the corners.

This will have cut the tounge off and right through the board at each end. There may now be enough freedom of movement to lift the board along the cut edge and prise it out. But I suspect that as this is a newly laid floor it is very tight. Cut along the otherside and the board will lift out..

As there are screws in the joints choose a metal cutting jigsaw blade with the smallest kerf you can find.

But are you sure of the location of the leak. Is there a joint in the pipe about where the damp is showing? What is the pipe? Copper doesn't generally spontaneously just leak and we haven't had any hard frosts yet. Plastic might have been nibbled.

[newshound]

+1.

[cf-leeds]

h is under the floor of the loft room.

ng below the pipe, to repair it, then patch up the ceiling again afterwards . It's an overboarded lath ceiling, so that should be fun.

T&G plank floor that I laid in the loft room, in order to get to the pipe. As you can guess, the problem is in the middle of the room, 1 m from the e dge.

then removing a small area of planks. I figured that I could then maybe re

-lay the removed plank area and on the final plank, remove half of the groo ve and the end tongue, in order to screw it down from above, then fill over the screw heads.

skirting etc.

e me any tips, e.g. how the break into the first plank - what would be the best type of saw to use ?

ne end. Just the thought of that spoils my day....

Thanks for all the responses - I suppose this thread has a part B:

">Copper doesn't generally spontaneously just leak and we haven't had any h ard frosts yet. Plastic might have been nibbled. "

The piping is Speedfit, not copper.

I think it's more than a coincidence that this leak started while I was rep lacing the bath on the floor below. While doing the plumbing for the new ba th, I was regularly turning the water off and on at the stop c*ck.

It was during this time that the leak occured. It's as if depressurising th e feed and repressurising it has somehow started the leak. first as a tiny wet patch, and now a persistent drip, if I leave the water on.

I've had to isolate the water supply to the loft, which passes up the wall in the downstairs bathroom via two chrome surface pipes. The leak is nowher e near that point, but looking at my vast foto archive of when the loft con version was in progress (2+ years ago), it seems the leak is in the vicinit y of pipe junctions.

Does this sound consistent with a push fit failure ?

Thanks Chris

[Capitol]

IMO, this is where you need a 3" circular saw with a thin carbide tipped blade. Lidl/Aldi sell them from time to time. I have a Sears one and it has been my tool of choice for board cutting on almost all occasions. The saw depth can be set to just cut through the tongue and being carbide won't care about the screws. They are extremely accurate to use and only cut a 2mm wide slot at the most. The underlying chipboard can be removed by cutting a smaller hole in the chipboard layer on a second cut. As the depth is adjustable, it can be set to just the chipboard thickness. A starting plunge cut is easily achieved. Sorry, I don't have a link available at this time.

[Capitol]

I'm old and embittered, I won't use push fit plumbing.

[cf-leeds]

Now you mention it, I did see some circular saws on offer at Aldi last week . I might see if they stil have any.

RE: Pushfit

I too do everything in copper, but the guys we had do the loft conversion u sed them. When I saw the plumber using pushfit, I said I wanted copper and we then had a long conversation about the pros and cons. He convinced me it was ok to use them. OK - I know, he was just making his own life easier an d I should have held out.

Cheers

Chris

I too am now old and embittered.

[DICEGEORGE]

multitool, theyre coming up in aldi on Thursday

[Tricky Dicky]

Got to agree with the multi tool as it enables you to cut right on the jois t. I find this gives a much better levelling when replacing the floor board than securing a support batten to the side of a joist. Only downside it is probably slower than circular saw but can give a neater cut without the o ver cuts into the neighbouring boards.

Richard

[Adam Funk]

Yes, definitely. I got one of these recently & it's much better for several reasons:

• you can cut in the middle of the joist (as you said);

• it cuts down rather than "on the pull" so it doesn't splinter the floorboard upwards;

• it cuts down so you can work (carefully!) over pipes.

[Adam Funk]

I already have a Bosch one but thanks very much for bringing that to my attention --- I see will be selling spare blade sets too, & I could use some of those.

[Bob Minchin]

+1 I will only ever use copper. These problems might only appear rarely on UK DIY but often enough for me to still to "luddite?" ways.

[RJH]

I have a battery one of those. I wouldn't fancy using it on 18mm floorboards. It'd get there but slowly. Would a mains version be much better?

[Chris French]

I've used my mains one for cutting floorboards and it's fine. Obviously not as quick as a circular saw, but much more controlled. And really, if you are lifting a few boards the time factor really doesn't matter.

[Adam Funk]

Same here, for a small number of boards. I guess I could use a circular saw but with the following disadvantages:

1. much thicker kerf, unless I buy a thin blade for the purpose (my circular saw is on indefinite loan from my brother-in-law, who has a better one now);
2. harder to control depth (set in advance & hope it's right, rather than cut down until the board comes loose);
3. because of (2), a bit riskier over pipes (or even worse, cables);
4. more likely to cut into adjacent boards that don't need to be cut.

[PeterC]

Although I've found the straight blade on the Bosch to be best for floorboards, the 'semi-circular' one has a depth of cut to the er, change of thickness in the middle that is almost c*ck-on the same as the thicknes of (my) floorboards. This is good for unknown areas as it shouldn't get as far as pipes etc. - especialloy useful if there are plastic pipes as they don't complain when cut. Tha replacement blade from Aldidl is plain, so it can cut deeper.