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Chat Area => General Discussion Area => Topic started by: Sir Tigger KC on 27 April 2019, 14:30:47

Title: Denso Tape
Post by: Sir Tigger KC on 27 April 2019, 14:30:47
I had a leak in a buried pipe where it goes under the kitchen floor to the bathroom which I've dug out and fixed the leak.  :y

This morning I wrapped the pipes in Denso tape before cementing over, but after wrapping the pipes, I washed my hands in the bathroom and when I went back to the kitchen I found that the tape on the hot pipe had turned to mush!  :o

This dosn't seem normal to me, so I thought I'd better get professional advice from the OOFeratti before I bury the pipes in cement.  :)
Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 14:50:21
Don't bury copper pipe in cement/concrete  :o

copper pipe will corrode, you will get massive heat sink into the concrete (underfloor heating )

obviously you will ignore that advice  ;D

 so.......

 put closed cell insulation lagging on clicky  (https://www.wickes.co.uk/Wickes-Pipe-Insulation-Byelaw-22-x-1000mm-Pack-3/p/210012)wrapped with waterproof tape  :-X


Title: Re: Denso Tape
Post by: Sir Tigger KC on 27 April 2019, 15:03:26
Don't bury copper pipe in cement/concrete  :o

copper pipe will corrode, you will get massive heat sink into the concrete (underfloor heating )



Whoever laid the pipes there in the first place wrapped the pipes with duct tape, which obviously wasn't up to the job of protecting the pipes from the corrosive alkaloids in the cement.  I thought that Denso tape was the proper stuff to use?  :-\ 

The 'trench' isn't deep enough for the foam insulation stuff you linked to, so that's no good.  ::)

If I hadn't washed my hands, it would all be nicely encased in cement now and odds on I wouldn't have been any the wiser...  ::)  :P
Title: Re: Denso Tape
Post by: STEMO on 27 April 2019, 15:06:25
Denso tape is for a temporary repair on cold water systems where there is no pressure, i.e. rainwater pipes, gutters, etc. It's basically no more than grease held together with fabric.
Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 15:12:41
Don't bury copper pipe in cement/concrete  :o

copper pipe will corrode, you will get massive heat sink into the concrete (underfloor heating )



Whoever laid the pipes there in the first place wrapped the pipes with duct tape, which obviously wasn't up to the job of protecting the pipes from the corrosive alkaloids in the cement.  I thought that Denso tape was the proper stuff to use?  :-\ 

The 'trench' isn't deep enough for the foam insulation stuff you linked to, so that's no good.  ::)

If I hadn't washed my hands, it would all be nicely encased in cement now and odds on I wouldn't have been any the wiser...  ::)  :P

ask the OOF mod team to delete this thread, cover pipes up, take a blue memory loss pill, job jobbed  :y
Title: Re: Denso Tape
Post by: STEMO on 27 April 2019, 15:13:25
Piccy please.
Title: Re: Denso Tape
Post by: Andy H on 27 April 2019, 15:13:41
Wrapping pipe in Denso tape is an age old attempt to prevent the cement burning through the copper but as you have rediscovered Denso is not heat resistant (I think it is fabric impregnated with wax or grease :-\)

Running pipes in the screed pretty much guarantees that screed will crack along the line of the pipe - (this might not matter to you depending on what your final floor covering is)

Insulating the pipes is probably not an option as the overall diameter of the insulated pipes will be close to the depth of the screed.

When I pulled up the floor screed of the downstairs bathroom in my house the copper pipes had a factory PVC sleeve which seems to have prevented corrosion and coped with heat. When I re-piped it I clipped the pipes to the wall....
Title: Re: Denso Tape
Post by: STEMO on 27 April 2019, 15:22:05
Wrapping pipe in Denso tape is an age old attempt to prevent the cement burning through the copper but as you have rediscovered Denso is not heat resistant (I think it is fabric impregnated with wax or grease :-\)

Running pipes in the screed pretty much guarantees that screed will crack along the line of the pipe - (this might not matter to you depending on what your final floor covering is)

Insulating the pipes is probably not an option as the overall diameter of the insulated pipes will be close to the depth of the screed.

When I pulled up the floor screed of the downstairs bathroom in my house the copper pipes had a factory PVC sleeve which seems to have prevented corrosion and coped with heat. When I re-piped it I clipped the pipes to the wall....
There's an echo in here. ::)
Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 15:23:16
what floor covering is going down on top ?
if laminate planks, you could use expanding foam rather than concrete
(giving the pipe insulation )

or re-route the pipe ,as Andy says

or swap for b-pex pipe if you want the underfloor heating aspect  :-\
Title: Re: Denso Tape
Post by: Sir Tigger KC on 27 April 2019, 15:40:34
Piccy please.

Sorry no piccys available till Tuesday as I'm not back  there until then, which is why I wanted to cement it over today so it could dry out undisturbed for a few days.  ::)


what floor covering is going down on top ?

Ceramic tiles, so it'll need a solid base to stop the tiles from cracking.  :(

Re-routing the pipes isn't an option, as that would be a massive job pulling the kitchen units out and they'll get wrapped in duct tape again before that happens!  ;)  ;D

Nothing is ever ficking straight forward is it?  >:(  ::)

Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 15:56:16
this is why,when designing a kitchen etc, you need to plan ,starting with the services .
don't clicky  (https://www.youtube.com/watch?v=p6lTIk1iC5I) :-X  :y
Title: Re: Denso Tape
Post by: Doctor Gollum on 27 April 2019, 16:39:06
Fill the 'trench' with sand and lay the tile over it :-\
Title: Re: Denso Tape
Post by: Lizzie Zoom on 27 April 2019, 18:07:31
How about using gaffer tape? ;)
Title: Re: Denso Tape
Post by: biggriffin on 27 April 2019, 18:49:48
Another wurzel bodge up, have you been on ch5 yet dodgey old landlords.
Title: Re: Denso Tape
Post by: Bigron on 27 April 2019, 19:11:05
Bitumen roofing sealant?

Ron.
Title: Re: Denso Tape
Post by: Sir Tigger KC on 27 April 2019, 19:35:12
Another wurzel bodge up, have you been on ch5 yet dodgey old landlords.

Good landlords fix problems. Dodgy landlords don't.  :P
Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 19:50:51
Another wurzel bodge up, have you been on ch5 yet dodgey old landlords.

Good landlords bodge problems. Dodgy landlords don't.  :P
FTFY  :y
Title: Re: Denso Tape
Post by: biggriffin on 27 April 2019, 21:07:25
Another wurzel bodge up, have you been on ch5 yet dodgey old landlords.

Good landlords bodge problems. Dodgy landlords don't.  :P
FTFY  :y

That's what I meant.. :)
Title: Re: Denso Tape
Post by: dave the builder on 27 April 2019, 21:14:50
had you disconnected the boiler,removing heating and hot water from the equation ,denso tape may have sufficed
tip for next time  :y
or have a cowboy builder on speed-dial  ;D
Title: Re: Denso Tape
Post by: aaronjb on 29 April 2019, 08:41:17
My old house had copper pipes buried in the concrete floor when it was built in 1970.

In 2017 they leaked, 47 years later.

Will you still own the house in 47 years? Of course not, you're on OOF, you probably won't be alive in 47 years  :P :P Bury them and forget about it. :y ;)
Title: Re: Denso Tape
Post by: Doctor Gollum on 29 April 2019, 12:11:46
My old house had copper pipes buried in the concrete floor when it was built in 1970.

In 2017 they leaked, 47 years later.

Will you still own the house in 47 years? Of course not, you're on OOF, you probably won't be alive in 47 years  :P :P Bury them and forget about it. :y ;)
Some poor bastid will remember tales from Gramps about a site where no questions went unanswered and will be jumping up and down when this thread pops up in a search ::)
Title: Re: Denso Tape
Post by: aaronjb on 29 April 2019, 12:35:07
 ;D But that's their problem ;)

Unless Sir Tig has some children he's leaving the place to.. in which case, maybe do the job 'properly' ;D
Title: Re: Denso Tape
Post by: Doctor Gollum on 29 April 2019, 12:41:13
;D But that's their problem ;)

Unless Sir Tig has some children he's leaving the place to.. in which case, maybe do the job 'properly' ;D
Denso tape should be just fine then :D
Title: Re: Denso Tape
Post by: Sir Tigger KC on 29 April 2019, 12:45:08
;D But that's their problem ;)

Unless Sir Tig has some children he's leaving the place to.. in which case, maybe do the job 'properly' ;D
Duct Denso tape should be just fine then :D

 ::)
Title: Re: Denso Tape
Post by: Doctor Gollum on 29 April 2019, 12:45:59
If only to hold the tiles down :P
Title: Re: Denso Tape
Post by: Marks DTM Calib on 29 April 2019, 16:00:49
Use Kuterlux plastic coated copper pipe if you have no buried joints, if not wrap it in a couple of layers of PVC tape (cheap and available in decent widths).

I would then add insulation over the top as this will help the heat loss to the slab a bit, even a thin layer will bee better than nothing (assuming there is enough room).

Title: Re: Denso Tape
Post by: STEMO on 29 April 2019, 16:16:39
Brain fart  ;D