How to mark positions from plastic pipes in walls?

[OneMoreFarang]

I am renovating and there will be some new plastic pipes. With some of those pipes it is easy. They go straight from the ceiling to stop valve. The stop valve will be visible so it's easy to know the positions of those pipes.

But how about irregular pipes like i.e. drainage pipes from ACs? They are somewhere in the wall and they need a slope. Obviously it is theoretically possible to mark the exact position in a plan. But that has to be done and has to be done 100% correct that that might be a challange.

 

With electric lines or metal pipes it's easy to detect them with the correct tools - and not even expensive.

 

But what to do with plastic pipes?

If later I want to hang something on a wall and I know there is a plastic pipe somewhere how do I know exactly where it is?

Would it make sense to i.e. include a piece of wire, without any connection, near the pipe? Or maybe some kind of metal tape which can later be detected?

What do people do to know where exactly there are plastic pipes in the walls?

 

This is a picture of such a pipe in a wall. It's just one example. 

 

[Peterw42]

I think you will find the more expensive stud finders can pick-up plastic pipes. but otherwise, cheaper ones can detect the pipes when water is flowing in them, if that helps. Also, you can hear the water flow putting an ear and a glass to the wall.

[yeahbutif]

All pipes and wire Should run vertical from the socket or valve if hidden in a wall.. Aircon drain pipes would be in trunken...on surface of walls..

[OneMoreFarang]

21 minutes ago, yeahbutif said:

All pipes and wire Should run vertical from the socket or valve if hidden in a wall.. Aircon drain pipes would be in trunken...on surface of walls..

Why should I look at ugly AC drainpipes on the surface of the wall when they can be hidden inside the walls? 

[RayWright]

Did something similar with air-con drip pipe in Spain and UK. Supply is easy as copper. For drip used mini fixing plates every 150mm. BluTak/mastic/silicon to fix to chased plastic pipe. Left note stuck to A/C for any future owner/engineer.

[Peterw42]

40 minutes ago, yeahbutif said:

All pipes and wire Should run vertical from the socket or valve if hidden in a wall.. Aircon drain pipes would be in trunken...on surface of walls..

Most new builds or renovations have the pipes hidden in the walls, and connected to the kitchen/bathroom/stormwater drainage, ducting (and draining out to the balcony) is usually only when air-conn is fitted later. I've lived in 4 condos in Thailand and they all had the pipes hidden, 

Edited September 1, 2022 by Peterw42

[HighPriority]

If the wall is a cavity block or similar ie 90mm wide with a 30mm “skin” on each side and therefore a 30mm cavity would allow you to hang pictures etc.

If the wall is rendered it gives you a bit more tolerance. 
Ideally as mentioned above, any pipe work should run vertically rather than 45 deg/60 deg or whatever.

[The Hammer2021]

25 minutes ago, OneMoreFarang said:

Why should I look at ugly AC drainpipes on the surface of the wall when they can be hidden inside the walls? 

Perhaps your original  question answers  this.

[OneMoreFarang]

5 minutes ago, HighPriority said:

If the wall is a cavity block or similar ie 90mm wide with a 30mm “skin” on each side and therefore a 30mm cavity would allow you to hang pictures etc.

If the wall is rendered it gives you a bit more tolerance. 
Ideally as mentioned above, any pipe work should run vertically rather than 45 deg/60 deg or whatever.

Thanks

the "problem" with the AC drainage pipe is that they need a slope - otherwise they don't work as intended.

[Crossy]

If you take photos of the pipes before plaster / render and file them you have a record. Do ensure there's a reference point that won't get hidden so you can match photo to pipe later.

 

For your A/C drain maybe run it just off horizontal across from the A/C to a corner, then straight down.

[HighPriority]

1 hour ago, OneMoreFarang said:

Thanks

the "problem" with the AC drainage pipe is that they need a slope - otherwise they don't work as intended.

I comprehendo, but you either run them with a 5/10% fall direct from the ac to the external wall (keep ‘em up high babe) or you drop them vertically to 100/200mm above floor level and then fall them 5/10% to the external wall.

Running diagonally across the wall is just asking for future dramas.

[carlyai]

3 hours ago, OneMoreFarang said:

Why should I look at ugly AC drainpipes on the surface of the wall when they can be hidden inside the walls? 

Then run them vertically and horizontally. 

[NanLaew]

9 hours ago, OneMoreFarang said:

This is a picture of such a pipe in a wall. It's just one example. 

 

What on earth does that achieve? A n% overall saving in pvc pipe?

 

I'm with the "run vertical or horizontal" brigade of running stuff parallel with walls, floors, etc... Also that's why they make elbows.

[carlyai]

4 hours ago, OneMoreFarang said:

Thanks

the "problem" with the AC drainage pipe is that they need a slope - otherwise they don't work as intended.

You can always put a pump on the drain outlet and run it thru the ceiling.

[HighPriority]

6 hours ago, carlyai said:

You can always put a pump on the drain outlet and run it thru the ceiling.

Remember Murphy’s first law of thermodynamics… if it’s mechanical it’ll shiite itself sooner or later. 

[DrDave]

There's a product called Walabot that was heavily promoted in the US a couple of years ago that attaches to your phone and claims to see just about anything up to 4" deep into the wall. Not sure how well it works on block walls, but you might want to have a look to see if it would be of any use for your situation.

[OneMoreFarang]

11 hours ago, HighPriority said:

I comprehendo, but you either run them with a 5/10% fall direct from the ac to the external wall (keep ‘em up high babe) or you drop them vertically to 100/200mm above floor level and then fall them 5/10% to the external wall.

Running diagonally across the wall is just asking for future dramas.

Thanks, good idea!

Now let's look how successful I will be to explain that to the AC guys... 

[OneMoreFarang]

8 hours ago, carlyai said:

You can always put a pump on the drain outlet and run it thru the ceiling.

Yes, that is an option and I thought about it.

But in general I prefer not to add anything electric if a mechanical solution is sufficient.

[degrub]

Put an ac drain isolation valve near the evaporator. This is a ball valve kitted with a schraeder valve  (like on your car tire) fitting on each side of the valve.  Allows you to blow the line clear with a short blast of compressed air  when you get a biofilm plugging the drain line. 
 

you also will want to be able to isolate the drain vent from the evaporator so that you can put a little bleach in the line every month to kill  biofilms that will grow. Chlorine gas from the bleach will attack the evaporator coil metal over time.

[degrub]

And make sure you pressure test the line if you are going to cover it up permanently. Too easy to get a bad glue joint on pvc that you don’t find until you have to unclog the line. 
 

you can also run the drain line outside and just cover it with U shaped gutter or similar to hide it.

[IvorBiggun2]

Youtube is your friend.  

 

 

Edited September 2, 2022 by IvorBiggun2

[IvorBiggun2]

Also

 

 

[OneMoreFarang]

1 hour ago, degrub said:

Put an ac drain isolation valve near the evaporator. This is a ball valve kitted with a schraeder valve  (like on your car tire) fitting on each side of the valve.  Allows you to blow the line clear with a short blast of compressed air  when you get a biofilm plugging the drain line. 
 

you also will want to be able to isolate the drain vent from the evaporator so that you can put a little bleach in the line every month to kill  biofilms that will grow. Chlorine gas from the bleach will attack the evaporator coil metal over time.

Thanks, that sounds like a good idea.

If you don't mind can you please add a link and/or a picture to such a valve?

I want to make sure I don't select the wrong type.

[OneMoreFarang]

3 hours ago, OneMoreFarang said:

14 hours ago, HighPriority said:

I comprehendo, but you either run them with a 5/10% fall direct from the ac to the external wall (keep ‘em up high babe) or you drop them vertically to 100/200mm above floor level and then fall them 5/10% to the external wall.

Running diagonally across the wall is just asking for future dramas.

Thanks, good idea!

Now let's look how successful I will be to explain that to the AC guys... 

A little follow up. I spoke with my project manager, and she will convince the AC guys to install it like @HighPriority suggested. Thanks!

 

This proves again that sometimes this forum is really useful. 

[VocalNeal]

1 hour ago, degrub said:

when you get a biofilm plugging the drain line. 

I use one of these.

If you connect the rubber hose to the side port it acts like a vacuum cleaner and sucks out the "gunge". Just be careful where you point the outlet.

 

[degrub]

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwi-hp6AlPX5AhVBLkQIHVw4CJEQFnoECBIQAQ&url=https%3A%2F%2Fwww.amazon.com%2FCondensate-Blow-Out-Valve-Ball%2Fdp%2FB00QJ0QKH2&usg=AOvVaw3fVv9WtW-Ukmvm5-RxcSSh

 

this one has a single schrader connection. You have to rotate the valve handle in the correct direction as it will direct the air one way or the other depending on direction of rotation 

[AsianAtHeart]

Could always sheath the (jointless) pipe in a segment of galvanized pipe.  A nail would be hard-pressed to pass through it, though a drill would probably still penetrate with a bit of persistence.  I'd be concerned about the quality of the joints.  Those need to be joined very well, with full insertion, held for at least 30 seconds after inserting them.  Many Thai "plumbers" are careless with the PVC joints, and they can actually blow apart sometimes under pressure, after a couple years' use.

 

It's important to understand that "PVC glue" is not glue at all.  It is a solvent that dissolves the PVC temporarily.  After the two pieces have both partly dissolved and are pushed together, they fuse--basically welded plastic.  Adding glue to the outside of the joint does nothing but delay the curing time--but I've seen many do this.  It is not a sealant, nor a glue.

[degrub]

And they better de-burr the pipe end, prime coat the pipe & fitting, “glue” coat, insert and twist quarter turn to full depth to get a good join. 
 

The “glue” never fully hardens. You can carefully cut and peel the pipe out of a fitting if you want. 

[Bill97]

23 hours ago, OneMoreFarang said:

Obviously it is theoretically possible to mark the exact position in a plan. But that has to be done and has to be done 100% correct that that might be a challange.

So you have a contract that does not include “as built plans”? 
 

Or is your problem about 100% correct?

[OneMoreFarang]

1 hour ago, Bill97 said:

So you have a contract that does not include “as built plans”? 
 

Or is your problem about 100% correct?

A lot of the work in my renovation project is supervised by the main contractor. But some work, like the AC installation, is done by another team.

I have the current plans and I should get “as built plans”, and maybe they will be 100% correct.

But obviously I don't know how correct they will be. And for that reason it would be good to be able to "see" where the pipes are, and not where they should be.

I will for sure take some pictures of the walls when it's still possible to see the exact locations of the pipes.