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Just imagining you cutting through the tanking to put in a back box, or putting retaining screws ... I worked in an undersea road tunnel once and all drills were kept under guard :)
 
Neither I believe surface mount and stick them on as there should be no holes in the membrane, if they are screwed in then the damp will penetrate to the back box via the screws.

Is there an architect involved on the job?

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If you "damage" the membrane then you will be up sh!t creek without a paddle.
 
Just imagining you cutting through the tanking to put in a back box, or putting retaining screws ... I worked in an undersea road tunnel once and all drills were kept under guard :)

Yeah but the drill for the Channel Tunnel wasn't a battery operated jobbie that you bought from Screwfix........
 
Double sided sticky tape in true Blue Peter fashion.

I've never worked on a tanked installation, but don't they frame out in timber after the tanking? Then you run cables and fix boxes within the frame as normal. No damage to membrane at all
 
Neither I believe surface mount and stick them on as there should be no holes in the membrane, if they are screwed in then the damp will penetrate to the back box via the screws.

Is there an architect involved on the job?

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If you "damage" the membrane then you will be up sh!t creek without a paddle.

Surely that's puddle? :)

Those fixings will not be suitable for mounting standard backboxes,and rely on drilling in to sound masonry,no joints or soft material,or re-sealing applies.

A lot will depend on what type of board or finish system is being used. Keeping the accessory mounting and installation,to the inner of any membrane.

Hydraulic head is relentless,and you only need to be an inch,the wrong side,above or below,to have moisture ingress through the inner sheath of a t&e cable,never mind the entry points.

If you want an easy example of this,get yourself a bucket full of water,and put it on a table. Cut two feet of t&e,bend it in to a "U" shape,and hook it over the edge of the bucket,so one side is in the water,and the other hangs down,past the bottom.

Check it in a few days.

As mentioned,any perforating of a designed system,whether tanking,or insulation,ventilation etc,should be done to the architect's spec...although they are quite often "eel" like,in this regard.

And remember,a good architect always has the time honoured,statutory reply of "Conditions,methods and practices should be assessed by a qualified and experienced professional,on site,and during progress,and appropriate steps taken to ensure compliance with all relevant....blah blah..."

Ring said architect up,and second sentence is "If your man is an experienced professional,he should know how to sort it..."

Small rant over- due to recent heated discussion with alleged qualified architect,who believed it was possible to get stone and sand,to a tricky access job,via a concrete pump...

He was quite sure they had "got round that issue,by pumping..." right up to the point where i suggested i ring my youngest son,and he could ask him...he finally wilted,and mentioned he may have got confused with a render-pumping job...he then composed himself,and chirpily ask "So is your son in the building trade,then?"

I think he got the message,after i explained me lad was 10,and at junior school... :rolleyes:
 
Depends what's going in after the membrane my only experience of it is dry lining boxes nothing screwed to the membrane
 
If you are tanking a place its not uncommon for any cable drops and accessories to come down from ceiling and stop at the 1.2m in your case to avoid breaking the seal and sometimes use drylining to have an offset from the protected wall to avoid any holes. You would amazed at how water and moisture can find a route in even the tiniest of holes
 
Double sided sticky tape in true Blue Peter fashion.

I've never worked on a tanked installation, but don't they frame out in timber after the tanking? Then you run cables and fix boxes within the frame as normal. No damage to membrane at all
Hope fully the ones doing the boarding didn't drill through the membrane.......
 
@magnoliafan89 You will quite often come across 'tanking' when doing basement refurbs or where there is a high risk of moisture penetrating through walls and nowadays most often seen when turning normal bath or shower rooms into wet rooms or walk in showers. you in effect create a rubber like coat on the walls, floor etc to stop moisture penetrating. its sort of like turning the whole room into one water containment zone. on a smaller scale its used when tiling in bathrooms before the tiles go on to stop water going through the wall and damaging plaster.
 
The use of plastic or rubber membrane to contain water is simple enough for even me to understand, but shouldn't it be on the outside? In the case of a wet room the walls support the membrane from any water pressure, but how can this work in a basement built below the water table? Does my head in o_O .
 
The use of plastic or rubber membrane to contain water is simple enough for even me to understand, but shouldn't it be on the outside? In the case of a wet room the walls support the membrane from any water pressure, but how can this work in a basement built below the water table? Does my head in o_O .
I did a temporary supply with basic CU and small radial and light circuit when a building was being refurbed. they literally dug around the house and put a thick coat of latex type stuff on the outer walls of the basement, then coated in sheets of polystyrene and then coated that in a thick rubbery substance before back filling... once set it was 100% water proof, this with all layers ended up around a foot thick, on the inside they did something similar but much thinner,starting with the floor, it made the basement like a giant plastic tray... set forward from the lining inside was metal stud work on which dry lining etc sat on. it allowed them to put an extra flat in the basement and made them quite a bit of money. its quite common around here with so many basements being converted to accommodation from storage.
 
I've done wiring in such basement rooms where we've chased as normal first then the chases are coated with the tanking compound and the tubing and boxes fixed in with the cement rendering.
 
I've done wiring in such basement rooms where we've chased as normal first then the chases are coated with the tanking compound and the tubing and boxes fixed in with the cement rendering.
thats far too much common sense and straightforward for the stasi building control folks in bath... if there is a roundabout way of doing something they will dictate that is the way and god help anybody who might suggest otherwise!
 
The use of plastic or rubber membrane to contain water is simple enough for even me to understand, but shouldn't it be on the outside? In the case of a wet room the walls support the membrane from any water pressure, but how can this work in a basement built below the water table? Does my head in o_O .

Hi bud,in the case of a wet room,the tanking or waterproofing,is to prevent the water getting out. This is an easier proposition,as the floor and walls,support the membrane,and any pressure acting on it,by way of hydraulic head.

In the case of a cellar,the treatment or tanking,is there to prevent water getting in. In this regard,it is not supported,other than by adhesion,and will not prevent ingress by way of hydraulic head.

This applies no matter what any salesman or advert will tell you.

It resists against moisture which moves via absorption,migration,osmosis,etc

Any hydraulic head,that is sitting water above such a structure,ground water etc,is coming in. The end.

This is mitigated for,in proper work,by forming a ring channel,behind the tanking/support,which allows any water ingress,condensation,etc,to either drain via gravity,or to a sump arrangement,and then pumped to waste.

Try pushing a 25 litre plastic drum,with the lid cut off,in to a larger tub of water...300mm in and it will fold. What happens to your body,if you dive down to the depth of a cellar?
Remember,head can build up in localised areas,and does not need to immerse an entire property.

You work with nature,not against it,and any product salesman who thinks he has fixed that quandary,is a fool indeed :)
 

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