ETC

Exactly - there is the idea that cavity insulation may be combustible and until this can be proved/disproved FR cavity closers will be required.

The other thing that comes to mind is the idea/notion/concept that where there isn’t a cavity (where the cavity is fully pumped with insulation) why on earth would you need a cavity closer? No cavity - no closer.🤷🏼‍♂️

The Approved Document is quite clear. You need to install FR cavity barriers to the perimeter of all external doors and windows. There are a number of ways of doing this and are listed in the AD - including the installation of calcium silicate board - https://www.promat.com/en-gb/construction/products-systems/products/fire-resistant-boards/supalux/ And yes - builders do cut calcium silicate board on site - I see it everyday. Some builders will line the complete jamb, head and cill with the board - others will cut a 50mm strip and close the cavity.

I suppose where these are used the FR is provided by some other means. Don’t forget that timber windows do not need a cavity barrier as long as the frame covers the cavity.

I’d like to see a test certificate for a 30 minute FR floor using insulated plasterboard below the floor joists.

I’m surprised that your BCO will allow you to put insulated PB to the underside of a FR floor.

Thinking how you insulate the garage walls. You will need self-closers on the fire-doors.

Had a look at your drawings - to be honest not great. Drawings look OK but the notes are - IMO - poor especially for a self- builder. I don’t see a heat detector/alarm in either in the Kitchen or Utility Room. Nor do I see smoke detectors in any of the Bedrooms - are they needed in England? I’m outside your jurisdiction and we need them here where I am. I presume your fire doors will have self-closers?

Q: Are these all the drawings? Have you got BC plan approval? Is your garage heated?

Post their identity. £1 says they’re not registered!

See my reply above - and read the diagram again - carefully!

You need to close the cavity to the perimeter of ALL external doors and windows with an 1/2HRFR cavity barrier irrespective of what insulation is in your cavity. The only “get out” for not installing a cavity closer is at the eaves and verge ONLY and that is on condition that the cavity is fully filled with insulation (pumped bonded bead being one example). However, until I see conclusive evidence that the insulation in a cavity is non-combustible I will always ask for the cavity to be closed at the eaves and verge.

1:40 fall for 4” pipes. 1:60 fall for 6” pipes.

300mm cover is required above all drainage pipes in pedestrian areas. 600mm cover is required above all drainage pipes In vehicular accessible areas. If you can’t get this put a bit of concrete over the pipes - 150mm minimum.

Read the BBA/BRE certificates. They will tell you if you need ventilation-some do and some don’t.

Don’t forget that a cavity barrier can be as simple as timber and plasterboard.

What centres are your links?

Your drawings should have been clear enough to determine if it’s a two or three-storey house. Building Control will have determined this from your drawings and would have asked for a protected staircase if they deemed it a three-storey house. I can’t believe that your drawings were that unclear.

https://www.instagroup.co.uk/our-products/insulation/cavity-wall/ Other suppliers are available.

Hi all, I want to add internal wall insulation to my 1970's block cavity walls. Pump the walls with insulation.

Pump the cavity.

Yes you can.