Daft question #999,999

[terryplumb]

Fit full bore isolation valves . Its quite simple to work out how much needs to be cut out of your existing pipes to accommodate isolators. Just measure how much pipe goes into each end of the valve. For instance ,if 15 mm of pipe goes into each end ,you cut out 30 mm of pipe. Using a wheel cutter will make it very easy.

 

[Roger465]

Fit full bore isolation valves . Its quite simple to work out how much needs to be cut out of your existing pipes to accommodate isolators. Just measure how much pipe goes into each end of the valve. For instance ,if 15 mm of pipe goes into each end ,you cut out 30 mm of pipe. Using a wheel cutter will make it very easy.

You're going to think I'm very stupid here, but... surely that isn't right, as the two lengths of pipe don't meet in the middle? There's the little ball valve, isn't there... so wouldn't you just have to remove a total amount of pipe equivalent to the length of the internal valve of the isolator?

Or am I really missing something... probably...

 

[terryplumb]

Let's say the valve is 60 mm total length. Pipe goes in 15 mm each end ,total 30 mm. So the bit in the middle is 30 mm isn't it. If you cut out 30 mm of pipe section ,and insert the valve ,the top of the pipe will be exactly the same height as it was. Its basic maths ,fek all to do with plumbing really.
Didn't explain very well in my previous post ,sorry !!

 

[Roger465]

Let's say the valve is 60 mm total length. Pipe goes in 15 mm each end ,total 30 mm. So the bit in the middle is 30 mm isn't it. If you cut out 30 mm of pipe section ,and insert the valve ,the top of the pipe will be exactly the same height as it was. Its basic maths ,fek all to do with plumbing really.
Didn't explain very well in my previous post ,sorry !!

Thanks Terry, got it now

 

[Roger465]

I like to keep you all entertained here, as a kind of payment for all the valuable advice… as mentioned above, the main reason for doing all this is that the waste is horribly corroded, and it mings from time to time, no matter how much bleach etc I chuck down it.

The pedestal is very narrow, and the water pipes completely obscure the waste pipe, no absolutely no chance of doing anything with the waste without removing the sink. Sink is siliconed to the wall, so can’t ease it up and lift the pedestal out, unfortunately – it all had to come down (big saw knife down between the basin and tiled wall).

Anyway, taps, waste etc removed from the basin now, basin all cleaned up and ready to reassemble with new taps, waste, and trap. For your amusement, here’s a piccie of the waste I took out (which took a LOOOOONG time and much swearing, as it was badly corroded and all fused together). Think somebody overdid it with the Plumber’s Mate, or whatever you call that stuff…

 

[Roger465]

On the last stretch now, hopefully, but still a problem as always… taps, water pipes all done, and no problems; but can’t get the waste to seal. I’ve fitted a new rubber seal and fibre washer, but the problem is that the waste pipe coming out of the ground is at a slight angle, and he trap isn't. At least I assume that’s why it’s leaking.

The leak is slight, but I can’t leave it like that, can I… there’s no way I can see of straightening the waste pipe, as it’s concreted into the floor, and pretty short. I’m working in a very cramped space too, making everything very awkward.

Any suggestions please? I have to use the “S” word, but must I resort to silicone?

Thanks

 

[HERTS P&D]

One of these is needed:

https://www.screwfix.com/p/thomas-d...VAuDtCh1CIg0TEAQYASABEgIK-_D_BwE&gclsrc=aw.ds

Andy

 

[terryplumb]

Your correct it's the angle of the waste pipe meeting the trap ,if your sure it's leaking at the bottom of the trap. Check the top end ,to be certain it's not leaking higher up and misleading you.
Can the waste pipe be moved to be close to the wall ,is there any play ?
If so you could change the trap for a small bottle trap . Use an elbow and coupler to marry up.

 

[Roger465]

One of these is needed:

https://www.screwfix.com/p/thomas-d...VAuDtCh1CIg0TEAQYASABEgIK-_D_BwE&gclsrc=aw.ds

Andy

Thanks Andy, but it's not leaking from under the basin - it's from the bottom of the trap, where it joins to the pipe in the floor..

 

[Roger465]

Your correct it's the angle of the waste pipe meeting the trap ,if your sure it's leaking at the bottom of the trap. Check the top end ,to be certain it's not leaking higher up and misleading you.

Cheers Terry, but it’s definitely leaking from the joint between the bottom of the trap and the grey pipe coming up out of the floor. If I move the joint slightly, some more dribbles out. I always wrap a dry bit of bogroll around all the joints, right up to the basin, to check for leaks anywhere.

Can the waste pipe be moved to be close to the wall ,is there any play ?

Unfortunately not… the whole setup is perfectly designed to frustrate me at every turn. The pedestal is narrow, and the hot and cold pipes block the opening at the back of it – there isn't any space to get the waste pipe through.

Somehow I’ve got to get this joint to seal

 

[CBW]

Could try x2 of the 135 degree spigot elbows? Presuming pushfit. https://www.hunterplastics.co.uk/products/plumbing/pushfit-waste/

 

[terryplumb]

Maybe possible to introduce a short flexible waste pipe. Cut the one from the floor ,make it shorter.

 

[CBW]

Maybe possible to introduce a short flexible waste pipe. Cut the one from the floor ,make it shorter.

Was going to suggest that, but didn’t want people to judge me.

 

[Roger465]

Was going to suggest that, but didn’t want people to judge me.

Is that because flexible pipes are generally regarded as a bit naff, or is there another reason? Must admit, I'm considering it (if I can figure out which one to get...)

 

[terryplumb]

Rigid waste pipes makes for a neater and more professional job ,and offer less resistance to flow ,and as the inner walls are smooth are less likely to hold solids and blockages.
However they do come in useful ,and in your circumstances won't cause any problems and behind a pedestal ,not to conspicuous. And will solve your misalignment problem fairly easily.