Wiring in 17th C Timber Framed house

[dans]

Renovation work is going great and moving on at a fast rate! I will post some pictures shortly of work to date...

I have a question for those who have experience in the past with wiring old buildings. Whilst I want to expose wall beams, I have in turn left myself with very little room for hiding wiring and pipework. What have people done in the past with running pipes through walls and floors? Ideally, I don't want to take up my floorboards which have been down for hundreds of years...

Many thanks,
Dan

 

[biffvernon]

Don't hide them.

 

[dans]

Don't hide them.

Legally, they now have to be in trunking. Which looks ugly!

 

[FamilyWiggs]

It's tricky. I lifted the boards to hide them, and some minor channeling in the plaster.

If you're lifting boards to lay cable, you may as well run pipework at the same time.

if you screw rather than anil the boards back down then it makes lfting them next time less destructive; albeit screws are more visible than nails.

 

[Jellyfire]

I'm currently in the same dilemma. All the cables are exposed at the moment, mainly running down the middle of beams which just looks awful, so I'd love to hide the wiring whilst I have the chance. I'm currently removing all the gypsum, repairing the daub where necessary and replastering in lime, I'm thinking of having the cables in trunking and then covering them in daub, apart from a gap for access top and bottom. Any thoughts on whether that would work? I'm loathe to lift floorboards as wouldn't want to damage them, and I suspect the ceilings would probably come crashing down too!

On a similar cautionary note, whilst hacking cement off the interior plinth over Easter (well its a kind of resurrection), I managed to slice my chisel through a live cable which was buried in the cement! I assumed all our wiring was visible, now I know they managed to hide some of it, which is why I think trunking may be safer for future custodians who attempt to hack through my daub!

 

[MdB]

Legally, they now have to be in trunking. Which looks ugly!

My understanding is surface runs are fine if combined with RCD / RCBO when in a position that is unlikely to be damaged. I'm not an expert on this though.

 

[Zebra]

To clip cables direct to the surface with cable clips is legal and an acceptable way of wiring. Not pretty perhaps but quite fine. Cables can also be chased into a wall and plastered over with no trunking or conduit, it is not a legal requirement to have it, it is only there to protect the cable from damage whilst plastering and is not considered to offer mechanical protection.

Any cables chased into a wall have to be in a direct vertical or horizontal line to the outlet that they supply, you cannot go in diagonal lines, or in higgledy piggledy routes up and over doors etc. This is to avoid the situation Jellyfire got into, because you'd be able to figure out where cables are likely to be buried.

Any cables chased into a wall now have to have RCD protection (17th Edition wiring regulations came in 2008) unless they are in EARTHED METAL conduit / at least 50mm deep in the wall, I don't imagine it is practical in your situation to comply with either of these. (This doesn't mean that you have to put RCD protection on existing cables chased into the wall, just that any new ones must have RCD protection.)

As far as ways of wiring an old house are concerned, it's tricky. I'm an electrician so I'm doing mine myself, and ery glad that I am, because there's a lot of head scratching going on. I shall plaster some walls, and have exposed timber on others, and I'm only putting outlets on walls which will be plastered. I've run cables in the void between the floorboards and the downstairs ceiling, and I got into it from below, I removed the ceiling and reinstated the laths. But I won't drill into any timber. Therefore I'm also running cables around the edges of the junction between the floor and the ceiling, ie weaving around the outside of the joist edges and the inside of the studs. It's quite intricate and unusual but doesn't contravene any regulations.

Hope this helps...

 

[FamilyWiggs]

But I won't drill into any timber. Therefore I'm also running cables around the edges of the junction between the floor and the ceiling, ie weaving around the outside of the joist edges and the inside of the studs. It's quite intricate and unusual but doesn't contravene any regulations.

Faced with a similar conundrum, I notched joists or drilled through them. I was concerned at the possibilty of movement of timbers with your method and then rubbing through the insulation.

 

[robgil]

I have one ambilical cord running the length of the house in a small section of cieling serving each room, central heating and electrics.
Anythiong surface mount will be very tidy and nice to look at , the bulk of it will be hidden.
You just have to sit down and think it through, a compramise might have to be made such as a false section of ceiling for example.

My light switchewws (edwardian brass dolly switches and bakelite) are surface mount and have that cloth covered cable serving them from junction boxes, much nicer than T+e.

What colour are your wires? red and black?
Where are you Dans?

 

[Jellyfire]

Any cables chased into a wall now have to have RCD protection (17th Edition wiring regulations came in 2008) unless they are in EARTHED METAL conduit / at least 50mm deep in the wall

My understanding is surface runs are fine if combined with RCD / RCBO when in a position that is unlikely to be damaged. I'm not an expert on this though.

I have a feeling I may need to get an electrician in! So much for my plans for using hosepipes embedded in the daub!

 

[Flyfisher]

We have lots of surface metal conduit and it seems to blend in rather better than bare cables and clips. Perhaps because looks more like pipework than wiring?

Adding RCD protection to existing and new wiring should be quite a simple and non-invasive thing. We've had it done by simply replacing the old fuse box. The safety advantages are such that I wouldn't want to be without such protection.

 

[agbagb]

Any cables chased into a wall have to be in a direct vertical or horizontal line to the outlet that they supply, you cannot go in diagonal lines, or in higgledy piggledy routes up and over doors etc. This is to avoid the situation Jellyfire got into, because you'd be able to figure out where cables are likely to be buried.

You might want to check on this. I was recently told that if you record the position of hidden cables in a file, they can go anywhere you like. The file should be a permenant record that gets past on with the house.

I'm going through the same process at the moment, some first fix wiring and plumbing just in yesterday. It makes for a challenging puzzle.
Pull cords for light switches have solved a few tricky bits.

 

[MdB]

You might want to check on this. I was recently told that if you record the position of hidden cables in a file, they can go anywhere you like. The file should be a permenant record that gets past on with the house.

I don't have a copy of the regs to look up but I can't believe that this is true. Vertical or horizontal from fixture or within 100mm(??) of an edge, buried more than 50mm or RCD or metal earthed trunking.

 

[agbagb]

Yes you still need the RCD, I'll be getting a new fuse board to sort that out.
I'm going on the advice of 17th edition electician about the file, it'll to good to have this advice confirmed.

I'm also contending with de-rating or providing air gaps around cableing passing through the new loft insulation and not bunching cables together eg. altogether through the same holes.
The now prefered radial instead of rings make things a bit easier. As many sockets as I like off one 2.5mm t&E of a 20amp breaker (baring in mind total likely load)
Some of the lighting will be done making the distribution connections in the switch backs instead of at the rose. So only one 1.5mm t&e to route to the ceiling.

On the plumbing side I'm using 10mm copper pipe for the final runs to radiators, much easier to route through and tidier to box in / hide behind skirting.

 

[Zebra]

You might want to check on this. I was recently told that if you record the position of hidden cables in a file, they can go anywhere you like. The file should be a permenant record that gets past on with the house.

No I don't think that's correct, but is it in the regulations? I'd be interested to know which regulation number it is...

 

[Zebra]

The now prefered radial instead of rings make things a bit easier. As many sockets as I like off one 2.5mm t&E of a 20amp breaker (baring in mind total likely load)
Some of the lighting will be done making the distribution connections in the switch backs instead of at the rose. So only one 1.5mm t&e to route to the ceiling.

In fact the limitation in terms of what you can put on a circuit (radial or ring) depends on circuit length and floor area rather than number of outlets, although it's also down to the person who designs it to make sure it's not likely to be overloaded.
Yes I've done the same thing with having lighting junctions in junction boxes elsewhere so that only one 1.5mm T&E has to go up to the upstairs ceiling.

 

[Zebra]

You might want to check on this. I was recently told that if you record the position of hidden cables in a file, they can go anywhere you like. The file should be a permenant record that gets past on with the house.

No I don't think that's correct, but is it in the regulations? I'd be interested to know which regulation number it is...

I've been thinking about this, the Wiring Regulations aren't statutory, you can have something which doesn't comply, if you declare it on the certification as a deviation. This is perhaps the option that the person who suggested that was thinking, as I'm pretty sure that the situation you describe isn't in the Regulations. However, if you do something which is a deviation from the Regulations, you have to demonstrate that the installation would be no less safe than if you had complied. So I still don't think this is a very good option, because the file could get lost or not passed on.
Once you get into deviation from the Wiring Regulations, then what is or is not OK gets rather subjective! You'd think Wiring Regulations would be cut and dried, but as with everything, there are differences of opinion...
Sorry everyone who's moved on from this point, just needed to clarify!

 

[MdB]

Put it like this, I wouldn't bury wires outside of the recognised areas - it just doesn't seem sensible.

 

[dans]

To clip cables direct to the surface with cable clips is legal and an acceptable way of wiring. Not pretty perhaps but quite fine. Cables can also be chased into a wall and plastered over with no trunking or conduit, it is not a legal requirement to have it, it is only there to protect the cable from damage whilst plastering and is not considered to offer mechanical protection.

Any cables chased into a wall have to be in a direct vertical or horizontal line to the outlet that they supply, you cannot go in diagonal lines, or in higgledy piggledy routes up and over doors etc. This is to avoid the situation Jellyfire got into, because you'd be able to figure out where cables are likely to be buried.

Any cables chased into a wall now have to have RCD protection (17th Edition wiring regulations came in 2008) unless they are in EARTHED METAL conduit / at least 50mm deep in the wall, I don't imagine it is practical in your situation to comply with either of these. (This doesn't mean that you have to put RCD protection on existing cables chased into the wall, just that any new ones must have RCD protection.)

As far as ways of wiring an old house are concerned, it's tricky. I'm an electrician so I'm doing mine myself, and ery glad that I am, because there's a lot of head scratching going on. I shall plaster some walls, and have exposed timber on others, and I'm only putting outlets on walls which will be plastered. I've run cables in the void between the floorboards and the downstairs ceiling, and I got into it from below, I removed the ceiling and reinstated the laths. But I won't drill into any timber. Therefore I'm also running cables around the edges of the junction between the floor and the ceiling, ie weaving around the outside of the joist edges and the inside of the studs. It's quite intricate and unusual but doesn't contravene any regulations.

Hope this helps...

Thanks zebra!

Looks like I'm going to have to surface mount a lot on mine, as I'm also exposing cielings downstairs...

Want to quot a rewire job in Norwich??

 

[Flyfisher]

I've been thinking about this, the Wiring Regulations aren't statutory, you can have something which doesn't comply, if you declare it on the certification as a deviation. This is perhaps the option that the person who suggested that was thinking, as I'm pretty sure that the situation you describe isn't in the Regulations. However, if you do something which is a deviation from the Regulations, you have to demonstrate that the installation would be no less safe than if you had complied. So I still don't think this is a very good option, because the file could get lost or not passed on.

That's very interesting. I take the point about the possibility of a file being lost or not passed on, but surely that also applies to any declarations on a certificate?

As for safety, knowing where a cable is buried in a wall doesn't miraculously protect it from being drilled into (he says with a red face ), so I'm not sure that's a particularly good safety argument. What makes buried cables safe, I think, are protective devices such as RCDs. Drill into such a protected cable and the RCD trips with no (human) harm done. In which case, why not have zig-zagging buried cables if absolutely necessary?