Timber framed buildings... and the temple of doom

[l4urence]

All. Bear with me. I'm doing some research into electrical installation into timber framed buildings. This is not about a new build in first fix but much later modification. These constructions provide a thin service void which may or not be fit for purpose but I'm specifically interested in any thoughts, advice, links about travelling through the inside wall to the outside - through the membrane and the puncture damage to it - a potential stramash (thanks @richy3333).

I understand from a rather dated NICEIC book I have from the 90's referring to the 16th Edition warning that puncturing this membrane will result in catastrophic failure later, things we really don't like if we would be providing a certificate with our name on it. We know this already. There appears to be little real detail about this on google, codes of practice, documentation or advice. Part B is a long read but I am trawling through it.

NAPIT recently put this up on PE Wiring Timber-Frame Buildings - https://professional-electrician.com/technical/wiring-timber-frame-buildings/ - which has got me started on this question.

Imagine a timber framed home build that that later needs an EV charger for their brand new car, a socket outside, lighting in the garden, shed power, jacuzzi or anything else you had think of. The cable will need to travel at some point through a wall to the outside and resealing this membrane is important. Proving that this was done correctly is my quest. Since, I'm pretty certain there will be other holes made in this membrane (or holes already) and I would like to be able to prove that any 'catastrophic failure' in the future wasn't caused by my work.

This is just research and provoking comment right now, links, reading material, experience and thoughts appreciated. In return, I can summarise information and publish for review in the resources section of this site. Thanks in anticipation.

 

[Pretty Mouth]

It's difficult to imagine the tiny amount of condensation that might form on the cold side of the insulation from such an opening would ever cause any problems.

 

[Bellendian]

If it's a draughty hole from a humid room...say an outside socket fed from kithen or utility...then the volume of humid air drawn through the hole could be significant. I'd suggest that all you can do is holesaw a big enough hole in the drylining to allow access to the vcl and seal the hole with sealant prior to making good the plasterwork.

 

[Dustydazzler]

If we are talking about vapour barriers then no the barrier should not be broken.
If it needs to be broken then a large hole in the wall should be cut , the cable or pipe fed through and a new barrier seal In stated

 

[telectrix]

i blame all these new-fangled uni degree spit-outs. come up with wonderful ideas with no concept of the reality that mundane things like gas, water, electrickery need installing. bricks and mortar have stood the tests of time, been around since me and pete999 worked on Rameses's tomb.

 

[telectrix]

remember a job once back in the early 90's, old monastery next to a pub. big refurb, builders erecting acrows on the "concrete" floor of the 1st storey. they were totally confude by the fact that the floor was sinking. turned out the "concrete " floor was 12" thick straw, skimmed top and bottom with a hard lime and something compound back i the 16th century.

 

[Pretty Mouth]

This is a theoretical problem only, surely? I almost never see vapour barriers installed in ceilings, yet the loft insulation immediately above is always bone dry. Timber frame's hardly a new method of construction, has anyone here ever heard of failure due to cables, pipes and so on passing through the vapour barrier? I certainly haven't.

 

[l4urence]

This is a theoretical problem only, surely? I almost never see vapour barriers installed in ceilings, yet the loft insulation immediately above is always bone dry. Timber frame's hardly a new method of construction, has anyone here ever heard of failure due to cables, pipes and so on passing through the vapour barrier? I certainly haven't.

You have good points here. I don’t know of any ‘catastrophic’ failures but... perhaps it’s the designers get out clause. There is documentation about not puncturing the membrane though and (and I’m being selfish) I don’t want to be someone a finger is pointed at IF EVER a catastrophe happens! These things come back to bite us (much) later and it’s the rich developers of these cheap houses that’ll want to be blame us! Hence some research needed.

 

[l4urence]

i blame all these new-fangled uni degree spit-outs. come up with wonderful ideas with no concept of the reality that mundane things like gas, water, electrickery need installing. bricks and mortar have stood the tests of time, been around since me and pete999 worked on Rameses's tomb.

Totally agree but that’s the stramash <g> we are dealing with. You did a great job of Rameses's tomb but no documentation... tut tut!

 

[l4urence]

If we are talking about vapour barriers then no the barrier should not be broken.
If it needs to be broken then a large hole in the wall should be cut , the cable or pipe fed through and a new barrier seal In stated

Do you have any documentation or codes of practice for the repair that I can research. I’m not doubting you’ve not done this at all but looking for ‘official sources’ to comply. They built these house and appear to have little responsibility in providing working practices in the real world.

 

[Edtwozeronine]

If ever I wanted to be sure something was sealed after drilling a large hole I'd ram it full of grip-fill.