Insulating the flat roof and tiling the pitched roof

Day 22: Pitched Roof Tiled and Flat Roof Insulated and Felted, Radiator Pipes and Mains Electric Cables Laid

August 12th 2013

Today was a busy day and building seems to be speeding up. 2 builders were working on the roof, one tiling and the other building the flat roof section. The other 2 builders were working inside. They installed the electric cables and plates (5 double sockets, one in each corner plus an extra behind the TV), my audio cables (4 speaker cables and a coax with RCA for a sub-woofer). Also set up was the extension pipe from a radiator. And the 2 windows arrived – although not Velux as expected. I think cheaper than Velux so I am not complaining.

Very handy witnessing the electrics going in (and photographing) as I will now always know exactly where it is safe to drill holes in the future. Most cable will be under the floor with just a uprights directly under the sockets.

This is not the standard way though, ideally the electrics should have gone up and over. If they ever need to be replaced it will be a nightmare, so let’s hope they do not. Had an independent electrical inspector look and he gave it the all-clear.

Lots of photos.

A double socket and my audio cables.

Insulation board above the rafters on the flat roof. More insulation will go between the rafters.

Old outside light socket – I think the new ceiling light will feed off this

A flexible pipe from a radiator (will be covered) and an electric socket which has been taken for the living room. A new fitted bookcase will conceal all of this. UPDATE: this was all ripped out when a plumber saw how crap it was.

The first tiles go up. Or down.

Another socket

Mains electric from the house. Those stupid pipes were replaced by a proper plumber.

Speaker cables

My speaker cable runs along the front of the room. Will hopefully be able to test it before the floor goes in!

2013-08-13 15.23.55

Main wall with 3 double sockets. I will still need an extension lead for the home cinema

Main wall with 3 double sockets. I will still need an extension lead for the home cinema

2013-08-13 15.24.00

Radiator pipes with the mains electric cable


Tiles over the felt, over the fascia board

Tiles over the felt, over the fascia board

2013-08-13 16.43.15

Layer of flat roof insulation visible

Tar ready for the flat roof

Tar ready for the flat roof

The roof windows

The roof windows – Tyrem DPX500 – “standard double glazing with argon gas and low E coating”


2013-08-13 16.40.26

Just needs a gutter

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  13 comments for “Insulating the flat roof and tiling the pitched roof

  1. tel
    August 19, 2013 at 9:55 pm

    who the hell installed those cables, stevie wonder? certainly not a qualified spark. i hope your building inspector is blind as well.

  2. Jon
    August 19, 2013 at 10:16 pm

    All the electrics are being checked and certified properly. What is the problem with them? If there is something specific I should raise with the builder please let me know!

  3. ben
    August 20, 2013 at 12:10 am

    why would you need an extension lead for the home cinema. can’t they put sockets in for you to run it.

  4. Jon
    August 20, 2013 at 12:18 am

    There are sockets Ben, 3 double sockets on one wall, and 2 doubles on the other. But for all the home cinema I would need at least 4 double sockets in one spot and I was advised on an electrical forum to just use an extension lead like everybody else.

    I am surprised that there are not 8 socket wall plates with ethernet etc. added too.

  5. August 20, 2013 at 9:14 am

    The person who installed the cabling was not an electrician..fact..almost certainly a builder..and why the hell would u build a new extension … then have to use an extension lead! you have been misinformed then misled.,,probably by your builder, who will be checking and certifying the electrics!! its a mess mate ,get a sparky in to do it properly

  6. Jon
    August 20, 2013 at 9:22 am

    I understand you. However, when I said extension it is not to extend the distance of the electrics, but simply because I have around 10 things plugged in to the tele area, i.e.

    dvd player
    sat box
    av amp
    stereo amp
    record player
    wireless router
    old dvd player (although almost defunct)
    blu-ray player
    sometimes games console

    So even with 6 sockets on that wall, I will still need extension lead. Does anybody have 10 sockets on the wall? Before the build I did search online extensively and found nothing – only advice to use an extension lead.

    “8 sockets for a tv sounds like a lot to me; I would consider a multiway extension depending on how much current is likely to be drawn.” Adam W, Electricians Arms Member,

  7. Steve
    August 22, 2013 at 7:22 pm

    Jon I would get an electrician in, use a builder for building a plumber for plumbing and an electrician for electrical. The electrical installation looks poor to say the least .

  8. Jon
    September 1, 2013 at 9:23 am

    In the process of speaking to electricians now for the rest of the work.

  9. donveeto
    January 4, 2014 at 11:35 pm

    Hi Jon,
    Just came across your website about your extension.
    Looking really good!
    We had a ground floor kitchen extension with a pitched tile roof similar to yours completed 4 years ago.
    During the recent storms, high winds and rain we have had leaks seeping through the new extension especially where the extension joins the house. Having checked the pitched roof I noticed the flashing was not properly fitted to the main building ( it was not chased into the wall but just folded up and held up with cement only, which is now cracking and letting in rain.
    Can you please tell me what insulation you have under your tiled pitched roof between the tiles and your ceiling plaster board. i think our roofer did not insulate the roof properly because when I take out one of the ceiling spot lights I can feel a strong drought coming through and when I shine a torch into the spotlight gap I cannot see any insulation but just a gap. I am trying to find out if it is compulsory to fit insulation and whether we have been short changed.



  10. Jon
    January 5, 2014 at 11:09 am

    Hi Donveeto,

    We had two layers of insulation in the roof, Immediately under the felt was a rockwool / loft type of insulation, and then wedged between each of the rafters was solid insulation (Celotex). This was cut to size and then hammered in (with a mallet) so it was in tight.

    The third photo on this page shows both types of insulation:

    As it happens there is some water still getting where I think it should not be – a little came through the vents in the soffit during the heavy rain, which suggests to me that some got past the tiles and ran down the felt. Tsk. Awaiting reply from my builder …..

  11. Donveeto
    January 7, 2014 at 5:44 pm

    Hi Jon,
    Thanks for your reply.
    We certainly do not have any rockwool or solid insulation, which is very worrying!
    The only difference with our extension is we have multiple spotlights, would that affect the amount of insulation used so it does not interfere with the electrics??
    I am getting a second opinion from another roofer to check over everything.

  12. Danil
    October 17, 2015 at 6:29 pm

    thanx, but very little about single pitch roof

  13. Jon
    January 3, 2016 at 8:33 pm

    Hi Danil, this is site is mostly about my extension, so I do not discuss every option available, just what I have had done on my house.

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